Suspension losses

Not that convinced to be honest, for a starters folks aren’t going to be
riding rumble strips but by mistake!

And if you’re going to be real world testing, testing on dirt roads with
all of the inconsistencies that brings is what gravel riders do. With the
dips as well as the bumps, plus ruts etc.

Rumble strip testing seems somewhat misleading ie it’s not that controlled
nor what riders do.

As ever claims that they influence pro athletes etc and started the wider
tire use, IMO it along with disks was adapted by consumers/commuters with
pro racers lagging behind with adoption and haven’t gone quite as wide, ie
stopped at 28 for the Pros where as 30/32 are fairly common among club
riders.

Post by Frank Krygowski
BTW, Jobst Brandt is mentioned in the article. I recall that in
discussing rolling resistance here, he insisted that "rolling
resistance" should be defined _only_ as the losses generated by tire
rubber's hysteresis. I disagreed, because that implied that solid rubber
tires a la 1880, or near infinite tire pressure, or even metal rims with
no tire, would be best. Anyone who has ridden an antique solid tire
"safety" bike knows how slow those tires were.

As ever is a what you want as well, on the old school road bike, I commute
on, 28mm felt on the twitchy side 32mm much more planted, the speed
difference I’m less concerned about, though at that level maybe wider is
faster? What is faster would depend on road/bike/rider.

Roger Merriman

AMuzi

2025-01-02 13:35:15 UTC

Post by Roger Merriman

Not that convinced to be honest, for a starters folks aren’t going to be
riding rumble strips but by mistake!
And if you’re going to be real world testing, testing on dirt roads with
all of the inconsistencies that brings is what gravel riders do. With the
dips as well as the bumps, plus ruts etc.
Rumble strip testing seems somewhat misleading ie it’s not that controlled
nor what riders do.
As ever claims that they influence pro athletes etc and started the wider
tire use, IMO it along with disks was adapted by consumers/commuters with
pro racers lagging behind with adoption and haven’t gone quite as wide, ie
stopped at 28 for the Pros where as 30/32 are fairly common among club
riders.

I don't have a coherent argument either way but a rumble
strip test introduces a repeatable experience so that
various data may be compared. Each rider on a dirt or
gravel path, and each ride experience by any given rider, is
an unique set of impedimenta such that data cannot be as
readily compared.

In short you make an interesting point but it's not
measurable for comparative purposes.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

b***@www.zefox.net

2025-01-02 15:42:31 UTC

Post by AMuzi
I don't have a coherent argument either way but a rumble
strip test introduces a repeatable experience so that
various data may be compared. Each rider on a dirt or
gravel path, and each ride experience by any given rider, is
an unique set of impedimenta such that data cannot be as
readily compared.
I don't have a coherent argument either way but a rumble
strip test introduces a repeatable experience so that
various data may be compared. Each rider on a dirt or
gravel path, and each ride experience by any given rider, is
an unique set of impedimenta such that data cannot be as
readily compared.

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.

In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.

Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.

A pair of series RLC circuits (one for the road-tire interface
and a second for the suspension-rider interface) would be a good
start. I'm not skilled enough to do the calculations, but others
on this group likely are. The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid mass but
rather a dissipative blob....8-)

Thanks for reading,

bob prohaska

AMuzi

2025-01-02 16:06:08 UTC

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.
A pair of series RLC circuits (one for the road-tire interface
and a second for the suspension-rider interface) would be a good
start. I'm not skilled enough to do the calculations, but others
on this group likely are. The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid mass but
rather a dissipative blob....8-)
Thanks for reading,
bob prohaska

Clever.

I take from that, you think the actual impact/height
change/velocity change etc from various irregular surfaces
can be quantified for any given random gravel (or road)
experience and used to compare efficiency for other iterations.

I hadn't thought of that, but if that's true then the rumble
strip test isn't necessary for comparison. Which assumes
sensors have adequate sensitivity across whatever range and
that software for that data truly derives actual impedimenta
values.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

b***@www.zefox.net

2025-01-02 17:06:09 UTC

Post by AMuzi
I take from that, you think the actual impact/height
change/velocity change etc from various irregular surfaces
can be quantified for any given random gravel (or road)
experience and used to compare efficiency for other iterations.

To a decent approximation, yes. Any surface profile can be represented
by a spectrum. Music is usually represented by "pink" noise, thermal
noise is white (uniform) and most real systems have noise proportional
to 1/f (imagine turn-on transients as singularities). A real road would
likely be some combination with the radius of the tire serving as a high
frequency filter.

Post by AMuzi
I hadn't thought of that, but if that's true then the rumble
strip test isn't necessary for comparison. Which assumes
sensors have adequate sensitivity across whatever range and
that software for that data truly derives actual impedimenta
values.

One would have to measure the force/deflection curves for both tires
and suspension elements, along with the masses of the sprung and unsprung
elements. Since losses are rate dependent, especially for suspensions
with hydraulic damping, a range of speeds/frequencies would have to be
measured. I think an accurate model would get fairly complicated, especially
if the rider were included. Each compliance (tire, suspension spring, seat
spring and rider body part that deflects) would have to be accounted for.

There are potentially four coupled resonators: Tires, swingarm/forks and
finally rider (divided into arms/torso sections probably). Overall, tests
on a rumble strip or drum with some kind of ergometer might be simpler.

Very likely the motor racing industry already has software that can do the
analysis. Most of the interest in that market is controlling resonances,
not minimizing losses, but otherwise the problems are very similar.

Thanks for writing!

bob prohaska

Frank Krygowski

2025-01-02 17:32:25 UTC

One would have to measure the force/deflection curves for both tires
and suspension elements, along with the masses of the sprung and unsprung
elements. Since losses are rate dependent, especially for suspensions
with hydraulic damping, a range of speeds/frequencies would have to be
measured. I think an accurate model would get fairly complicated, especially
if the rider were included. Each compliance (tire, suspension spring, seat
spring and rider body part that deflects) would have to be accounted for.
There are potentially four coupled resonators: Tires, swingarm/forks and
finally rider (divided into arms/torso sections probably). Overall, tests
on a rumble strip or drum with some kind of ergometer might be simpler.
Very likely the motor racing industry already has software that can do the
analysis. Most of the interest in that market is controlling resonances,
not minimizing losses, but otherwise the problems are very similar.

One further thought: If we accept (as I do) that jiggling the human
pedaler does cause loss in energy and speed, why aren't we all using
saddles with some sort of damped springing?

I know suspension seatposts exist, but even those are not popular on
road bikes.

ISTM that if more "suspension" is valuable via wider tires, it might
also be valuable via sprung saddles, if done right.

My wife used to ride a Brooks B72. Its four curly support wires gives
just a bit of spring action. It's now on my about-town 3 speed. That
bike never goes far, but I don't detect any detriments to the slight
springiness.

--
- Frank Krygowski

Roger Merriman

2025-01-02 19:34:57 UTC

One would have to measure the force/deflection curves for both tires
and suspension elements, along with the masses of the sprung and unsprung
elements. Since losses are rate dependent, especially for suspensions
with hydraulic damping, a range of speeds/frequencies would have to be
measured. I think an accurate model would get fairly complicated, especially
if the rider were included. Each compliance (tire, suspension spring, seat
spring and rider body part that deflects) would have to be accounted for.
There are potentially four coupled resonators: Tires, swingarm/forks and
finally rider (divided into arms/torso sections probably). Overall, tests
on a rumble strip or drum with some kind of ergometer might be simpler.
Very likely the motor racing industry already has software that can do the
analysis. Most of the interest in that market is controlling resonances,
not minimizing losses, but otherwise the problems are very similar.

Is some on gravel bikes and stem’s which tend to be fairly basic and move
in less than ideal ways, ie the stems tend to pivot which some riders
really don’t like.

Also while lighter they are outperformed by suspension ie Gravel suspension
forks.

But probably mostly that roadies and most Gravel riders are, are as roadies
are ie fairly conservative with technology choices.

Post by Frank Krygowski
ISTM that if more "suspension" is valuable via wider tires, it might
also be valuable via sprung saddles, if done right.

There is a difference between the bike being sprung and the rider,
something Specialised talked about with the Diverge and specifically the
one with suspension in the frame as well as the fork.

Which gives a different feel to for example suspension such as MTB has even
reduced down to gravel travel. Plus performance as well clearly.

Post by Frank Krygowski
My wife used to ride a Brooks B72. Its four curly support wires gives
just a bit of spring action. It's now on my about-town 3 speed. That
bike never goes far, but I don't detect any detriments to the slight
springiness.

Its not really a saddle intended for more than that, and for that use-case,
probably more that roadie and even MTBers are unlikely to like the feel of
the saddle moving in relation to the bottom bracket even if mildly.

Roger Merriman

b***@www.zefox.net

2025-01-03 01:45:49 UTC

Post by Frank Krygowski
One further thought: If we accept (as I do) that jiggling the human
pedaler does cause loss in energy and speed, why aren't we all using
saddles with some sort of damped springing?
I know suspension seatposts exist, but even those are not popular on
road bikes.

I'm using a suspension seatpost now, removed from a town bike. It's
slightly more comfortable. No idea if it's more efficient. Certainly
heavier, probably lossy unless I balance pedal effort to keep pressure
on the saddle constant. That difference is small at most.

Thanks for writing,

bob prohaska

Frank Krygowski

2025-01-03 04:36:02 UTC

FWIW, when coasting - especially on rough downhills - my habit is to
take some of my weight off the saddle, hoping the "suspension" offered
by my legs causes less jiggling of my body mass, so less energy loss.

--
- Frank Krygowski

AMuzi

2025-01-03 14:13:49 UTC

Post by Frank Krygowski
One further thought: If we accept (as I do) that jiggling
the human
pedaler does cause loss in energy and speed, why aren't
we all using
saddles with some sort of damped springing?
I know suspension seatposts exist, but even those are not
popular on
road bikes.

I'm using a suspension seatpost now, removed from a town
bike. It's
slightly more comfortable. No idea if it's more efficient.
Certainly
heavier, probably lossy unless I balance pedal effort to
keep pressure
on the saddle constant. That difference is small at most.

FWIW, when coasting - especially on rough downhills - my
habit is to take some of my weight off the saddle, hoping
the "suspension" offered by my legs causes less jiggling of
my body mass, so less energy loss.

+1 and very relevant to this discussion.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Radey Shouman

2025-01-03 15:46:33 UTC

To get back to the question of how this might be modeled, it's really
complicated. Sometimes all your weight is probably off the saddle,
meaning that any computation would have to figure out when there was
contact, and the forces generated by that contact.

You can read a whole book about it online, if you're ambitious:

https://www.yastrebov.fr/LECTURES/Yastrebov_NMCM_Wiley_ISTE.pdf

Not to mention that there is a poorly understood nonlinear control
mechanism involved, somewhat different for each individual.

--

Frank Krygowski

2025-01-03 16:44:17 UTC

Post by Radey Shouman

To get back to the question of how this might be modeled, it's really
complicated. Sometimes all your weight is probably off the saddle,
meaning that any computation would have to figure out when there was
contact, and the forces generated by that contact.
https://www.yastrebov.fr/LECTURES/Yastrebov_NMCM_Wiley_ISTE.pdf
Not to mention that there is a poorly understood nonlinear control
mechanism involved, somewhat different for each individual.

Wow. Yes, it's probably good to remind ourselves that whatever topic we
tyros discuss here has probably been the life's work of some true expert.

--
- Frank Krygowski

Catrike Rider

2025-01-03 17:43:25 UTC

On Fri, 3 Jan 2025 11:44:17 -0500, Frank Krygowski

Post by Radey Shouman

To get back to the question of how this might be modeled, it's really
complicated. Sometimes all your weight is probably off the saddle,
meaning that any computation would have to figure out when there was
contact, and the forces generated by that contact.
https://www.yastrebov.fr/LECTURES/Yastrebov_NMCM_Wiley_ISTE.pdf
Not to mention that there is a poorly understood nonlinear control
mechanism involved, somewhat different for each individual.

Wow. Yes, it's probably good to remind ourselves that whatever topic we
tyros discuss here has probably been the life's work of some true expert.

<LOL> "True experts" are a dime dozen.

Frank Krygowski

2025-01-02 17:17:22 UTC

Post by b***@www.zefox.net
But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.

I think that would be true only if the smooth pavement were as smooth as
a linoleum floor. Or a wooden track. IIRC, what got Jan Heine started on
investigations of rolling resistance vs. tire width was coast-down tests
on a Soapbox Derby track. I suspect that was quite smooth. Soapbox cars
have hard tires and no suspension, AFAIK.

Post by b***@www.zefox.net
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.
A pair of series RLC circuits (one for the road-tire interface
and a second for the suspension-rider interface) would be a good
start. I'm not skilled enough to do the calculations, but others
on this group likely are.

I _may_ have been able to do such calculations 50 years ago, but I'm not
sure. I certainly can't do them now.

Post by b***@www.zefox.net
The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid mass but
rather a dissipative blob....8-)

I actually think physically modeling that dissipative blob might be
valuable for the tire industry. Using such a blob to apply weight during
a rolling drum test might give better information than what those tests
give now.

Post by AMuzi
Clever.
I take from that, you think the actual impact/height change/velocity
change etc from various irregular surfaces can be quantified for any
given random gravel (or road) experience and used to compare efficiency
for other iterations.
I hadn't thought of that, but if that's true then the rumble strip test
isn't necessary for comparison. Which assumes sensors have adequate
sensitivity across whatever range and that software for that data truly
derives actual impedimenta values.

There are ways of quantifying roughness, with varying scales, varying
tools. I'm most familiar with roughness measurement of machined parts,
with tools varying from sample cards for "fingernail" test comparisons,
to RMS readers akin to phonograph needles or laser scattering devices.

https://en.wikipedia.org/wiki/Surface_roughness

ISTR reading about systems for evaluating pavement fairly crudely, as in
whether it should be repaved or not. I don't know of a system actually
used for measuring pavement roughness at a scale affecting bike tire
choice.

--
- Frank Krygowski

AMuzi

2025-01-02 17:35:05 UTC

Post by b***@www.zefox.net
But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.

I think that would be true only if the smooth pavement were
as smooth as a linoleum floor. Or a wooden track. IIRC, what
got Jan Heine started on investigations of rolling
resistance vs. tire width was coast-down tests on a Soapbox
Derby track. I suspect that was quite smooth. Soapbox cars
have hard tires and no suspension, AFAIK.

Post by b***@www.zefox.net
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire
and
suspenesion. In that limit, suspension would be faster if
used
with very hard tires on very smooth surfaces. In the
limit of
hard tires and no suspension, the dissipative element
becomes
the rider whose elastic properties are apt to be poor,
perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will
affect
dissipation depending on internal resonances of the bike/
rider
system. A real road likely corresponds to a 1/f spectrum,
but
a rumble strip will likely be something else. How much
difference
that makes isn't clear but it could be estimated using a
mechanical
analogy equivalent circuit of the kind used to model
loudspeakers.
A pair of series RLC circuits (one for the road-tire
interface
and a second for the suspension-rider interface) would be
a good
start. I'm not skilled enough to do the calculations, but
others
on this group likely are.

I _may_ have been able to do such calculations 50 years ago,
but I'm not sure. I certainly can't do them now.

Post by b***@www.zefox.net
The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid
mass but
rather a dissipative blob....8-)

I actually think physically modeling that dissipative blob
might be valuable for the tire industry. Using such a blob
to apply weight during a rolling drum test might give better
information than what those tests give now.

Post by AMuzi
Clever.
I take from that, you think the actual impact/height
change/velocity change etc from various irregular surfaces
can be quantified for any given random gravel (or road)
experience and used to compare efficiency for other
iterations.
I hadn't thought of that, but if that's true then the
rumble strip test isn't necessary for comparison. Which
assumes sensors have adequate sensitivity across whatever
range and that software for that data truly derives actual
impedimenta values.

There are ways of quantifying roughness, with varying
scales, varying tools. I'm most familiar with roughness
measurement of machined parts, with tools varying from
sample cards for "fingernail" test comparisons, to RMS
readers akin to phonograph needles or laser scattering devices.
https://en.wikipedia.org/wiki/Surface_roughness
ISTR reading about systems for evaluating pavement fairly
crudely, as in whether it should be repaved or not. I don't
know of a system actually used for measuring pavement
roughness at a scale affecting bike tire choice.

Yes, I'm familiar with surface finish (roughness) numbers in
machining, but an offroad bicycle, for example on a gravel
path (bianca strada) or babyheads (much of Paris Roubaix)
would be a series of variable impedimenta in some chaotic
non-order for height & frequency. The principle is the same
but the amount of data is staggering.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

b***@www.zefox.net

2025-01-03 02:26:32 UTC

Post by AMuzi
Yes, I'm familiar with surface finish (roughness) numbers in
machining, but an offroad bicycle, for example on a gravel
path (bianca strada) or babyheads (much of Paris Roubaix)
would be a series of variable impedimenta in some chaotic
non-order for height & frequency. The principle is the same
but the amount of data is staggering.

But, what matters is the sum of impediments over the path, regardless
of where in the path they turn up. So long as the potholes aren't
missed it doesn't matter exactly where they are. For something
regular, like Belgian block pavement, impediments line up and certain
paths might find or miss more or less of them, but over the course of
the path _most_ paths have essentially the same sum of deflections.

Gravel is a special case, because some of the losses occur in the
road surface. For that problem a tire that minimizes deflection of
the road is best.

Thanks for writing,

bob prohaska

b***@www.zefox.net

2025-01-03 02:03:51 UTC

Post by b***@www.zefox.net
But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.

I think that would be true only if the smooth pavement were as smooth as
a linoleum floor.

To first principles, it's the compliance of the tire that keeps alternating
forces out of the suspension. If suspension doesn't deflect there can't be
any losses. Since the tire always deflects it's always lossy. On a very
hard (10 bar) tire, that might take a linoleum floor. But, it's the tire
that decides what's "smooth".

Thanks for writing,

bob prohaska

Jeff Liebermann

2025-01-04 04:46:32 UTC

On Thu, 2 Jan 2025 12:17:22 -0500, Frank Krygowski

I _may_ have been able to do such calculations 50 years ago, but I'm not
sure. I certainly can't do them now.

Actually, the analogy between a mechanical system and RLC (resistance,
inductance and cazapitance) calculations are fairly simple. For
example:

"Mechanical-electrical analogies"
<https://en.wikipedia.org/wiki/Mechanical%E2%80%93electrical_analogies>

"Electrical Analogies of Mechanical Systems"
<https://www.tutorialspoint.com/control_systems/control_systems_electrical_analogies_mechanical.htm>

"RLC circuit: Analogy with mechanical systems." (From Brazil)
<https://proceedings.sbmac.org.br/sbmac/article/download/134486/3384/0>

Post by b***@www.zefox.net
The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid mass but
rather a dissipative blob....8-)

If you're going to build a computer simulation, there are cut-n-paste
mechanical models of various human bodies available.

"A mechanical model to determine the influence of masses and mass
distribution on the impact force during running"
<https://pubmed.ncbi.nlm.nih.gov/10653036/>
"Simple spring-damper-mass models have been widely used to simulate
human locomotion. However, most previous models have not accounted for
the effect of non-rigid masses (wobbling masses) on impact forces."

Ok, a running model is not going to work well on a bicycle. So, look
around for something that's a better fit. I'll admit that I've never
done anything like this, but I can see how it might be possible to
model a wobbling blob on a bicycle.

Also, modeling is NOT the hardest part of the problem. In my never
humble opinion, the most difficult part is dealing with the large
number of significant figured necessary to maintain accuracy. I human
or bicycle model might work accurate to maybe 1/10th of a watt, while
the power produced by a road bump powered energy harvesting system
might be on the order of fractions of a milliwatt. This forces the
human model to be accurate well beyond reasonable limits.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

Frank Krygowski

2025-01-04 18:02:24 UTC

Post by Jeff Liebermann
On Thu, 2 Jan 2025 12:17:22 -0500, Frank Krygowski

I _may_ have been able to do such calculations 50 years ago, but I'm not
sure. I certainly can't do them now.

Actually, the analogy between a mechanical system and RLC (resistance,
inductance and cazapitance) calculations are fairly simple. For
"Mechanical-electrical analogies"
<https://en.wikipedia.org/wiki/Mechanical%E2%80%93electrical_analogies>
"Electrical Analogies of Mechanical Systems"
<https://www.tutorialspoint.com/control_systems/control_systems_electrical_analogies_mechanical.htm>
"RLC circuit: Analogy with mechanical systems." (From Brazil)
<https://proceedings.sbmac.org.br/sbmac/article/download/134486/3384/0>

I'm pretty familiar with the RLC analogy to mechanical vibrations.

Actually, I remember sitting in a Vibrations class taught by my least
favorite professor on the day he brought in a large, demonstration-sized
Analog Computer (Remember those?) to model something we had been
calculating. To the amusement of the students, he was not able to get
the thing to work properly.

Post by b***@www.zefox.net
The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid mass but
rather a dissipative blob....8-)

If you're going to build a computer simulation, there are cut-n-paste
mechanical models of various human bodies available.
"A mechanical model to determine the influence of masses and mass
distribution on the impact force during running"
<https://pubmed.ncbi.nlm.nih.gov/10653036/>
"Simple spring-damper-mass models have been widely used to simulate
human locomotion. However, most previous models have not accounted for
the effect of non-rigid masses (wobbling masses) on impact forces."
Ok, a running model is not going to work well on a bicycle. So, look
around for something that's a better fit. I'll admit that I've never
done anything like this, but I can see how it might be possible to
model a wobbling blob on a bicycle.
Also, modeling is NOT the hardest part of the problem. In my never
humble opinion, the most difficult part is dealing with the large
number of significant figured necessary to maintain accuracy. I human
or bicycle model might work accurate to maybe 1/10th of a watt, while
the power produced by a road bump powered energy harvesting system
might be on the order of fractions of a milliwatt. This forces the
human model to be accurate well beyond reasonable limits.

My idea wasn't to model a human body for computation purposes, although
others are probably interested in doing that. I'm thinking more of
coming up with a physical device, perhaps for weighting a tire during a
rolling drum test, so the test would more accurately reflect behavior of
tires when ridden by a human pedaling a bicycle. Maybe 75 pounds of raw
meat?

--
- Frank Krygowski

AMuzi

2025-01-04 18:35:20 UTC

Post by Jeff Liebermann
On Thu, 2 Jan 2025 12:17:22 -0500, Frank Krygowski

I _may_ have been able to do such calculations 50 years
ago, but I'm not
sure. I certainly can't do them now.

Actually, the analogy between a mechanical system and RLC
(resistance,
inductance and cazapitance) calculations are fairly
simple. For
"Mechanical-electrical analogies"
<https://en.wikipedia.org/wiki/
Mechanical%E2%80%93electrical_analogies>
"Electrical Analogies of Mechanical Systems"
<https://www.tutorialspoint.com/control_systems/
control_systems_electrical_analogies_mechanical.htm>
"RLC circuit: Analogy with mechanical systems." (From
Brazil)
<https://proceedings.sbmac.org.br/sbmac/article/
download/134486/3384/0>

I'm pretty familiar with the RLC analogy to mechanical
vibrations.
Actually, I remember sitting in a Vibrations class taught by
my least favorite professor on the day he brought in a
large, demonstration-sized Analog Computer (Remember those?)
to model something we had been calculating. To the amusement
of the students, he was not able to get the thing to work
properly.

Post by b***@www.zefox.net
The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid
mass but
rather a dissipative blob....8-)

If you're going to build a computer simulation, there are
cut-n-paste
mechanical models of various human bodies available.
"A mechanical model to determine the influence of masses
and mass
distribution on the impact force during running"
<https://pubmed.ncbi.nlm.nih.gov/10653036/>
"Simple spring-damper-mass models have been widely used to
simulate
human locomotion. However, most previous models have not
accounted for
the effect of non-rigid masses (wobbling masses) on impact
forces."
Ok, a running model is not going to work well on a
bicycle. So, look
around for something that's a better fit. I'll admit that
I've never
done anything like this, but I can see how it might be
possible to
model a wobbling blob on a bicycle.
Also, modeling is NOT the hardest part of the problem. In
my never
humble opinion, the most difficult part is dealing with
the large
number of significant figured necessary to maintain
accuracy. I human
or bicycle model might work accurate to maybe 1/10th of a
watt, while
the power produced by a road bump powered energy
harvesting system
might be on the order of fractions of a milliwatt. This
forces the
human model to be accurate well beyond reasonable limits.

My idea wasn't to model a human body for computation
purposes, although others are probably interested in doing
that. I'm thinking more of coming up with a physical device,
perhaps for weighting a tire during a rolling drum test, so
the test would more accurately reflect behavior of tires
when ridden by a human pedaling a bicycle. Maybe 75 pounds
of raw meat?

Analog computer?
Like the fluid logic plate in an automatic transmission?

https://www.carid.com/acdelco/gm-original-equipment-automatic-transmission-valve-body.html--

Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Jeff Liebermann

2025-01-04 19:36:56 UTC

Post by AMuzi
Analog computer?
Like the fluid logic plate in an automatic transmission?
https://www.carid.com/acdelco/gm-original-equipment-automatic-transmission-valve-body.html--

Nope. The automobile automatic transmission is actually a digital
fluidic switch. When all the inputs and outputs are either on, off,
in, out, left, right, up down etc, it's digital. There are fluidic
analog computers. The key difference is how numbers are stored. In a
digital computer, numbers are stored as discrete numbers. In an
analog computer, numbers are stored as a range of values that require
interpolation to produce an output. When I asked Google the same
question, I received a rather wide range of answers:
<https://www.google.com/search?q=difference+between+analog+and+digital+computer>
That was a common point of contention as computers were being
developed (roughly 1960 thru 1990). I don't think anyone successfully
produced an answer that covered all types of computing devices.
Instead of an official answer, everyone just gave up by about 1990.

User manual on an early analog computer including a few useful
examples. Try to visualize what those problems might look like on a
slide rule or today's personal computers:
<https://www.analogmuseum.org/english/collection/eai/tr10/>
<https://www.analogmuseum.org/library/eai_tr-10.pdf>

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

AMuzi

2025-01-04 19:52:37 UTC

Post by AMuzi
Analog computer?
Like the fluid logic plate in an automatic transmission?
https://www.carid.com/acdelco/gm-original-equipment-automatic-transmission-valve-body.html--

Nope. The automobile automatic transmission is actually a digital
fluidic switch. When all the inputs and outputs are either on, off,
in, out, left, right, up down etc, it's digital. There are fluidic
analog computers. The key difference is how numbers are stored. In a
digital computer, numbers are stored as discrete numbers. In an
analog computer, numbers are stored as a range of values that require
interpolation to produce an output. When I asked Google the same
<https://www.google.com/search?q=difference+between+analog+and+digital+computer>
That was a common point of contention as computers were being
developed (roughly 1960 thru 1990). I don't think anyone successfully
produced an answer that covered all types of computing devices.
Instead of an official answer, everyone just gave up by about 1990.
User manual on an early analog computer including a few useful
examples. Try to visualize what those problems might look like on a
<https://www.analogmuseum.org/english/collection/eai/tr10/>
<https://www.analogmuseum.org/library/eai_tr-10.pdf>

Ah, such as a slide rule. Got it, thanks.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Frank Krygowski

2025-01-04 21:28:21 UTC

Post by Jeff Liebermann
User manual on an early analog computer including a few useful
examples. Try to visualize what those problems might look like on a
<https://www.analogmuseum.org/english/collection/eai/tr10/>
<https://www.analogmuseum.org/library/eai_tr-10.pdf>

Ah, such as a slide rule. Got it, thanks.

The device I was talking about was nothing like a slide rule. It looked
vaguely like the one in Jeff's last link above, but the classroom
demonstrator was much larger - maybe 3' x 4' IIRC - with much bigger
knobs (4" diameter?) and meters.

We were talking about electrical analogies for vibrating masses, and
that's one of the things the analog computer could simulate. One would
have to calculate the values of voltage, inductance and resistance to
correctly simulate the damped spring-mass system, set initial
conditions, then let the circuit run. The system's meters would then
swing back and forth in a manner analogous to the position of the mass.
All this was before digital computers were desktop devices.

(In those days, the programs I wrote for vaguely similar problems were
room sized and run by full time technicians, and I'd turn in a program
stored as a thick deck of punched cards, hoping output would be ready
the next day.)

As I recall, we students never did any actual work with that analog
computer.

--
- Frank Krygowski

AMuzi

2025-01-04 21:44:24 UTC

On Sat, 4 Jan 2025 12:35:20 -0600, AMuzi
User manual on an early analog computer including a few
useful
examples. Try to visualize what those problems might
look like on a
<https://www.analogmuseum.org/english/collection/eai/tr10/>
<https://www.analogmuseum.org/library/eai_tr-10.pdf>

Ah, such as a slide rule. Got it, thanks.

The device I was talking about was nothing like a slide
rule. It looked vaguely like the one in Jeff's last link
above, but the classroom demonstrator was much larger -
maybe 3' x 4' IIRC - with much bigger knobs (4" diameter?)
and meters.
We were talking about electrical analogies for vibrating
masses, and that's one of the things the analog computer
could simulate. One would have to calculate the values of
voltage, inductance and resistance to correctly simulate the
damped spring-mass system, set initial conditions, then let
the circuit run. The system's meters would then swing back
and forth in a manner analogous to the position of the mass.
All this was before digital computers were desktop devices.
(In those days, the programs I wrote for vaguely similar
problems were room sized and run by full time technicians,
and I'd turn in a program stored as a thick deck of punched
cards, hoping output would be ready the next day.)
As I recall, we students never did any actual work with that
analog computer.

Right. The values shown on that meter with a swinging
needle are analog, not digital; the scale and range can
approximate the value to an acceptable degree without a
specific digital value.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Jeff Liebermann

2025-01-04 23:20:03 UTC

On Sat, 4 Jan 2025 16:28:21 -0500, Frank Krygowski

Ah, such as a slide rule. Got it, thanks.

The device I was talking about was nothing like a slide rule.

I called the analog computer that I build in a briefcase an
"electronic slide rule". I didn't want to, but that made it more
acceptable to the college bureaucracy.

Post by Frank Krygowski
It looked
vaguely like the one in Jeff's last link above, but the classroom
demonstrator was much larger - maybe 3' x 4' IIRC - with much bigger
knobs (4" diameter?) and meters.

I couldn't find anything with such huge knobs. Maybe something like
these from Edmund Scientific?
<https://www.google.com/search?q=edmund+scientific+analog+computer&udm=2>

Would you believe a Heathkit EC-1 analog computer?
<https://www.google.com/search?q=heathkit+ec-1&udm=2>
<https://www.nutsvolts.com/magazine/article/may2016_heathkit_restoration>
Fig 7 is a bouncing ball simulation, which is similar to the bouncing
bicycle simulation.

Post by Frank Krygowski
We were talking about electrical analogies for vibrating masses, and
that's one of the things the analog computer could simulate. One would
have to calculate the values of voltage, inductance and resistance to
correctly simulate the damped spring-mass system, set initial
conditions, then let the circuit run. The system's meters would then
swing back and forth in a manner analogous to the position of the mass.
All this was before digital computers were desktop devices.

Meters? Too crude. We used an oscilloscope or X-Y pen plotter.

Post by Frank Krygowski
(In those days, the programs I wrote for vaguely similar problems were
room sized and run by full time technicians, and I'd turn in a program
stored as a thick deck of punched cards, hoping output would be ready
the next day.)
As I recall, we students never did any actual work with that analog
computer.

We did. My guess(tm) that would 1969. We had groups of 5 or 6
students sharing one machine. I got some extra experience because I
worked for the "calibration department" repairing them. The problem
was we had a large number of foreign exchange students from Iraq. Most
had never done any manual labor or learned to use tools. When faced
with a knob that had reached its end of rotation, they simply applied
more force to help it rotate. That usually broke the expensive 10
turn potentiometer (Helipot).
<https://www.google.com/search?q=helipot&udm=2>

I was the idiot who found a solution to the broken potentiometer
problem. Between the knob/turn_counter and the pot was a short shaft
extension. I machined a few of these and added a plastic shear pin.
If they hit the end of rotation and break the pin, all they had to do
was rotate everything full counter clockwise, push the pin out of the
hole, and replace it with a new pin (or toothpick). The reason I was
an idiot was because I had found the solution, I sentence to working
overtime retrofitting all the analog computers with shear pins.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

zen cycle

2025-01-05 10:40:18 UTC

Post by Jeff Liebermann
On Sat, 4 Jan 2025 16:28:21 -0500, Frank Krygowski

Ah, such as a slide rule. Got it, thanks.

The device I was talking about was nothing like a slide rule.

I called the analog computer that I build in a briefcase an
"electronic slide rule". I didn't want to, but that made it more
acceptable to the college bureaucracy.

I couldn't find anything with such huge knobs. Maybe something like
these from Edmund Scientific?
<https://www.google.com/search?q=edmund+scientific+analog+computer&udm=2>
Would you believe a Heathkit EC-1 analog computer?
<https://www.google.com/search?q=heathkit+ec-1&udm=2>
<https://www.nutsvolts.com/magazine/article/may2016_heathkit_restoration>
Fig 7 is a bouncing ball simulation, which is similar to the bouncing
bicycle simulation.

Meters? Too crude. We used an oscilloscope or X-Y pen plotter.

We did. My guess(tm) that would 1969. We had groups of 5 or 6
students sharing one machine. I got some extra experience because I
worked for the "calibration department" repairing them. The problem
was we had a large number of foreign exchange students from Iraq. Most
had never done any manual labor or learned to use tools. When faced
with a knob that had reached its end of rotation, they simply applied
more force to help it rotate. That usually broke the expensive 10
turn potentiometer (Helipot).
<https://www.google.com/search?q=helipot&udm=2>
I was the idiot who found a solution to the broken potentiometer
problem. Between the knob/turn_counter and the pot was a short shaft
extension. I machined a few of these and added a plastic shear pin.
If they hit the end of rotation and break the pin, all they had to do
was rotate everything full counter clockwise, push the pin out of the
hole, and replace it with a new pin (or toothpick). The reason I was
an idiot was because I had found the solution, I sentence to working
overtime retrofitting all the analog computers with shear pins.

I worked with a curmudgeonly older engineer many years ago who quipped
"do a shitty job well and it's yours forever".

Frank Krygowski

2025-01-05 16:25:33 UTC

Post by zen cycle
I worked with a curmudgeonly older engineer many years ago who quipped
"do a shitty job well and it's yours forever".

One of my colleagues had a sign in his classroom:
"If you don't have time to do it right, when will you have time to do it
over?"

--
- Frank Krygowski

AMuzi

2025-01-05 17:27:48 UTC

Post by zen cycle
I worked with a curmudgeonly older engineer many years ago
who quipped "do a shitty job well and it's yours forever".

"If you don't have time to do it right, when will you have
time to do it over?"

Per Ray Gasiorowsky, "There are two ways to do anything. The
right way and again."

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Jeff Liebermann

2025-01-05 21:26:09 UTC

Post by zen cycle
I worked with a curmudgeonly older engineer many years ago
who quipped "do a shitty job well and it's yours forever".

"If you don't have time to do it right, when will you have
time to do it over?"

Per Ray Gasiorowsky, "There are two ways to do anything. The
right way and again."

One of my former employers was very much into "first to market"
project design. Everything we did was fast and furious. His tag line
was something like "Do it right the first time because there won't be
a second time if the company goes broke".

This was somewhat put to the test when we were working on the
AN/SRD-22 Doppler direction finder for the USCG (US Coast Guard):
<https://www.learnbydestroying.com/jeffl/AN-SRD-22/>
We were at the point where the PCB's were being laid out when I had a
better idea, which would eliminate two of the major PCB's (printed
circuit boards), replace a control cable full of wires with one coax
cable, and substantially reduce the complexity and cost. I camped out
in my office for a weekend and built a working proof of concept
prototype.

Everyone agreed that it was better in every way. The problem was that
if we stopped the design process and switched to my new and improved
design, we ran the risk of missing the delivery deadline. It took a
few days to debate the change in direction, but when done, management
decided to go with the superior product. Amazingly, we met the first
article delivery deadline without any fatalities. It was about 3(?)
months between the decision and delivery. I got very little sleep and
was sweating bullets for the duration.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

John B.

2025-01-06 00:37:25 UTC

Post by zen cycle
I worked with a curmudgeonly older engineer many years ago
who quipped "do a shitty job well and it's yours forever".

"If you don't have time to do it right, when will you have
time to do it over?"

Per Ray Gasiorowsky, "There are two ways to do anything. The
right way and again."

Try that scheme when fixing airplanes... or submarines :-{

--
Cheers,

John B.

Jeff Liebermann

2025-01-05 20:46:28 UTC

On Sun, 5 Jan 2025 05:40:18 -0500, zen cycle

Post by Jeff Liebermann
I was the idiot who found a solution to the broken potentiometer
problem. Between the knob/turn_counter and the pot was a short shaft
extension. I machined a few of these and added a plastic shear pin.
If they hit the end of rotation and break the pin, all they had to do
was rotate everything full counter clockwise, push the pin out of the
hole, and replace it with a new pin (or toothpick). The reason I was
an idiot was because I had found the solution, I sentence to working
overtime retrofitting all the analog computers with shear pins.

I worked with a curmudgeonly older engineer many years ago who quipped
"do a shitty job well and it's yours forever".

True. However, that wasn't the problem. No sooner had I demonstrated
my solution, the calibration lab (and repair) manager was accosted by
literally everyone involved, each of which had a better idea. Since
everyone was also busy with something else and therefore could not
spare the time to prototype and test their ideas, and since I had
somehow managed to find some time to build and test my idea, and since
the manager didn't want anyone wasting their precious time working on
the problem, it was logically determined that I should be the chosen
one to build and test everyone else's ideas. Swell. Just what I
didn't need. Somehow, the Dean of Engineering became involved
(because blaming the Iraqi exchange students for creating the problem
was politically incorrect) and ordered that everyone working on it
should find something else to do. My good enough solution was
declared "good enough" and installed on all the Helipots that showed
damage (i.e. held together with electrical tape) until we ran out of
parts. I wasn't involved and moved on to (create) bigger and better
problems.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

AMuzi

2025-01-05 15:57:46 UTC

Post by Jeff Liebermann
On Sat, 4 Jan 2025 16:28:21 -0500, Frank Krygowski

Ah, such as a slide rule. Got it, thanks.

The device I was talking about was nothing like a slide rule.

I called the analog computer that I build in a briefcase an
"electronic slide rule". I didn't want to, but that made it more
acceptable to the college bureaucracy.

I couldn't find anything with such huge knobs. Maybe something like
these from Edmund Scientific?
<https://www.google.com/search?q=edmund+scientific+analog+computer&udm=2>
Would you believe a Heathkit EC-1 analog computer?
<https://www.google.com/search?q=heathkit+ec-1&udm=2>
<https://www.nutsvolts.com/magazine/article/may2016_heathkit_restoration>
Fig 7 is a bouncing ball simulation, which is similar to the bouncing
bicycle simulation.

Meters? Too crude. We used an oscilloscope or X-Y pen plotter.

We did. My guess(tm) that would 1969. We had groups of 5 or 6
students sharing one machine. I got some extra experience because I
worked for the "calibration department" repairing them. The problem
was we had a large number of foreign exchange students from Iraq. Most
had never done any manual labor or learned to use tools. When faced
with a knob that had reached its end of rotation, they simply applied
more force to help it rotate. That usually broke the expensive 10
turn potentiometer (Helipot).
<https://www.google.com/search?q=helipot&udm=2>
I was the idiot who found a solution to the broken potentiometer
problem. Between the knob/turn_counter and the pot was a short shaft
extension. I machined a few of these and added a plastic shear pin.
If they hit the end of rotation and break the pin, all they had to do
was rotate everything full counter clockwise, push the pin out of the
hole, and replace it with a new pin (or toothpick). The reason I was
an idiot was because I had found the solution, I sentence to working
overtime retrofitting all the analog computers with shear pins.

Thank you, especially for the Heath Kit page (although much
of that went beyond my understanding). The reader comments
were great, especially the last one!

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Jeff Liebermann

2025-01-05 20:58:28 UTC

Post by Jeff Liebermann
<https://www.nutsvolts.com/magazine/article/may2016_heathkit_restoration>

Thank you, especially for the Heath Kit page (although much
of that went beyond my understanding). The reader comments
were great, especially the last one!

Bad news. Most sundials are certainly analog, but there are some
almost digital exceptions:
<https://www.etsy.com/listing/976269465/digital-sundial>
<https://en.wikipedia.org/wiki/Digital_sundial>
<https://www.hineslab.com/optical-projects/digital-sundial-2/>
<https://www.reddit.com/r/mildlyinteresting/comments/atmurl/digital_sundial/>
More of the same:
<https://www.google.com/search?q=digital+sundial&udm=2>

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

zen cycle

2025-01-05 10:49:53 UTC

Post by AMuzi
Analog computer?
Like the fluid logic plate in an automatic transmission?
https://www.carid.com/acdelco/gm-original-equipment-automatic-transmission-valve-body.html--

Nope. The automobile automatic transmission is actually a digital
fluidic switch. When all the inputs and outputs are either on, off,
in, out, left, right, up down etc, it's digital.

Except for CVTs

Post by Jeff Liebermann
There are fluidic
analog computers. The key difference is how numbers are stored. In a
digital computer, numbers are stored as discrete numbers. In an
analog computer, numbers are stored as a range of values that require
interpolation to produce an output. When I asked Google the same
<https://www.google.com/search?q=difference+between+analog+and+digital+computer>
That was a common point of contention as computers were being
developed (roughly 1960 thru 1990). I don't think anyone successfully
produced an answer that covered all types of computing devices.
Instead of an official answer, everyone just gave up by about 1990.
User manual on an early analog computer including a few useful
examples. Try to visualize what those problems might look like on a
<https://www.analogmuseum.org/english/collection/eai/tr10/>
<https://www.analogmuseum.org/library/eai_tr-10.pdf>

Jeff Liebermann

2025-01-04 19:06:29 UTC

On Sat, 4 Jan 2025 13:02:24 -0500, Frank Krygowski

Post by Jeff Liebermann
On Thu, 2 Jan 2025 12:17:22 -0500, Frank Krygowski

Actually, I remember sitting in a Vibrations class taught by my least
favorite professor on the day he brought in a large, demonstration-sized
Analog Computer (Remember those?) to model something we had been
calculating. To the amusement of the students, he was not able to get
the thing to work properly.

Oh yes. That brings back memories of projects that should have died
on the drawing board. In early college, I couldn't afford a real
scientific calculator (HP-35). So, I decided to build an analog
computer in a briefcase. Two 10 turn Helipots with geared dials,
discrete analog multiplier, three log amps, a large mirrored meter and
a +/-15v power supply. I couldn't find any photos. It actually
worked. However, there was some controversy over allowing me to use
it for exams instead of a slide rule. I had to demonstrate how it
functioned to the administration (several times), until they
recognized that it was actually slower than a slide rule and that
there were no stored formulas or constants. When I was finally
allowed to use it in an exam, the instructor sabotaged my efforts
creating questions that squashed the numbers into the upper end of the
log scale, which made reading the results on the meter rather
difficult. I gave up and bought a Ti SR-10, which was a mistake:
<http://www.vintagecalculators.com/html/texas_instruments_sr-10.html>
I eventually obtained an HP-35 just in time to have the administration
temporarily ban the use of calculators during exams.

Post by Frank Krygowski
My idea wasn't to model a human body for computation purposes, although
others are probably interested in doing that. I'm thinking more of
coming up with a physical device, perhaps for weighting a tire during a
rolling drum test, so the test would more accurately reflect behavior of
tires when ridden by a human pedaling a bicycle. Maybe 75 pounds of raw
meat?

Ummm... How about a crash test dummy?
<https://www.google.com/search?q=crash+test+dummy&udm=2>

"Cycling crash test dummy"

Just one problem. They're expensive. Used dummies start at about
$100,000 and can easily cost $1 million with sensors and
instrumentation.

"How Crash Test Dummies Evolved To Cost $1 Million"

Maybe you should just use a reinforced mannequin?
<https://www.google.com/search?q=human+body+mannequin&udm=2>

75 lbs of raw meat might work, but I suspect would smell rather bad.
Perhaps ballistic gel might be a suitable substitute?
<https://www.google.com/search?q=ballistic+gel+dummy&num=10&udm=2>
My guess(tm) is about $2,500 for the dummy and underlying skeleton to
help hold it together.

Last resort would be to ask the experts:
<https://www.humaneticsgroup.com>

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

Frank Krygowski

2025-01-04 21:41:25 UTC

Post by Jeff Liebermann
<http://www.vintagecalculators.com/html/texas_instruments_sr-10.html>
I eventually obtained an HP-35 just in time to have the administration
temporarily ban the use of calculators during exams.

As a HP fan, my reaction to "... bought a TI SR-10" was "ewww."

You may be vaguely interested in this company:
https://www.swissmicros.com/products

Replica HP calculators. They seem to have a good reputation.

I'm doing well with my HP48G, thank you. But I still miss my HP11C that
was stolen while I worked at a little company with bad security.

--
- Frank Krygowski

Jeff Liebermann

2025-01-05 00:28:44 UTC

On Sat, 4 Jan 2025 16:41:25 -0500, Frank Krygowski

As a HP fan, my reaction to "... bought a TI SR-10" was "ewww."

Brain rot again. The Ti SR-10 was introduced in Nov 1972. I
graduated from college (Cal Poly Pomona) in June 1971. Obviously, I
couldn't have had that calculator while still in college. Yet, 54
years later, that's the way I remember it.

Same as the HP-35. Please ignore my comments about the SR-10 until I
have some time to untangle the mess. Again, sorry about the
confusion.

Post by Frank Krygowski
https://www.swissmicros.com/products

Nice products. I've played with a few of them owned by acquaintances.
Good display and some useful added features. I wish it had a
backlighted display. However, they're too expensive for my minimal
use.

Post by Frank Krygowski
Replica HP calculators. They seem to have a good reputation.

I'm not sure if they're a replica, clone, compatible device, or
work-alike. I haven't read the reviews, but what little I've skimmed,
it seems like a well built product.

Post by Frank Krygowski
I'm doing well with my HP48G, thank you. But I still miss my HP11C that
was stolen while I worked at a little company with bad security.

I'll look in my collection and see if I have an HP11C. Offhand, I
don't think so. There are some on eBay. The one's that offer the
least risk and are likely to work are $75 and up.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann

2025-01-05 00:40:33 UTC

Post by Jeff Liebermann
I'll look in my collection and see if I have an HP11C. Offhand, I
don't think so. There are some on eBay. The one's that offer the
least risk and are likely to work are $75 and up.

There's also the PX-11c. I don't know anything about how well it's
built or how it works.

<https://www.google.com/search?q=px-11c>
It's an HP-11c clone sold as a kit. $70 plus tax and shipping. Claims
it's 4 to 5 times faster than the HP version:

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

Frank Krygowski

2025-01-05 01:51:16 UTC

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.

The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.

When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

--
- Frank Krygowski

Jeff Liebermann

2025-01-10 05:20:12 UTC

On Sat, 4 Jan 2025 20:51:16 -0500, Frank Krygowski

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.
The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.
When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

I finally remembered to look into my boxes of HP calculators. I don't
have an HP 32SII or something comparable. In the scientific
calculator section, I found an HP 31E and a 32E. Both of these are
low end RPN calculators with LED displays. The 31E had a battery leak
at some time in the past and will require that I do some battery
contact rebuilding. I can provide a complete list of what I have in
stock.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

zen cycle

2025-01-10 10:19:53 UTC

Post by Jeff Liebermann
On Sat, 4 Jan 2025 20:51:16 -0500, Frank Krygowski

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.
The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.
When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

I never could get used to the RPN data entry method

Jeff Liebermann

2025-01-10 15:25:48 UTC

On Fri, 10 Jan 2025 05:19:53 -0500, zen cycle

Post by Jeff Liebermann
On Sat, 4 Jan 2025 20:51:16 -0500, Frank Krygowski

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.
The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.
When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

I never could get used to the RPN data entry method

Humans tend to prefer whatever technology they learned first. My
first calculator was basically a mechanical "adding machine".
<https://www.google.com/search?num=10&q=marchant+adding+machine&udm=2>
I eventually ended up with an HP-35 RPN calculator and loved it. RPN
is easy, if you think like a computer that stores intermediate results
in a stack. At home, I use an HP-41CX or an emulator on my phone and
PC. There are benefits and detriments to both algebraic and RPN
notation. If we can become accustomed to QWERTY keyboards designed to
slow down typing, we can get used to anything. I can switch back and
forth between algebraic and RPN. Algebraic for financial calculations
and RPN for engineering. Evaluating long equations is easier (for me)
using RPN.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

Shadow

2025-01-10 16:28:26 UTC

Post by Jeff Liebermann
On Fri, 10 Jan 2025 05:19:53 -0500, zen cycle

Post by Jeff Liebermann
On Sat, 4 Jan 2025 20:51:16 -0500, Frank Krygowski

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.
The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.
When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

I never could get used to the RPN data entry method

There's a freeware HP-42S emulator here:

<https://thomasokken.com/free42/>

Just unzip the binary to a flashdrive (or whatever). If you
put an empty file called "portable" in the same folder it won't write
anything to your HD.

I don't use it much, but it is very actively maintained. Last
version was this year.
[]'s

--
Don't be evil - Google 2004
We have a new policy - Google 2012
Google Fuchsia - 2021

Wolfgang Strobl

2025-01-10 22:18:27 UTC

Am Fri, 10 Jan 2025 07:25:48 -0800 schrieb Jeff Liebermann

Post by Jeff Liebermann
On Fri, 10 Jan 2025 05:19:53 -0500, zen cycle

Post by Jeff Liebermann
On Sat, 4 Jan 2025 20:51:16 -0500, Frank Krygowski

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.
The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.
When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

I never could get used to the RPN data entry method

Humans tend to prefer whatever technology they learned first.

Not really. I learned programming by creating punched cards using an IBM
26 Printing Card Punch, editing those programs by using the card
duplicating feature of those machines. Followed by pinnig stretches of
pages printed by large chain printers like to a wall, in order to study
complaints from the Fortran IV compiler, or using a pen to mark logical
errors in the source code, for later correction work on said card punch.

<https://en.wikipedia.org/wiki/IBM_1403>

I prefered almost every new programming technology that I learned later.
Sometimes, technology development takes the wrong path, naturally we
shouldn't and couldn't follow every idea, just because it is new. Simply
because several competing ideas are usually in vogue and are cheered on
by their enthusiastic fans.

Post by Jeff Liebermann
My
first calculator was basically a mechanical "adding machine".
<https://www.google.com/search?num=10&q=marchant+adding+machine&udm=2>
I eventually ended up with an HP-35 RPN calculator and loved it. RPN
is easy, if you think like a computer that stores intermediate results
in a stack.

Of course. If you do. But while I did study the matter (computer
science, that is), I don't think like a computer. I don't use RPN when
writing mathematical formulas, neither on paper, nor while programming.
Before you ask, I do know FORTH, I've even ported and changed an almost
unknown FORTH like language, adding traditional operator precedences to
the implementation, as a side project.

There is nothing wrong with RPN, if it works for you. But there isn't
anything "natural" about it.

Post by Jeff Liebermann
At home, I use an HP-41CX or an emulator on my phone and
PC. There are benefits and detriments to both algebraic and RPN
notation.

Yep.

I rarely used calculators, because writing short program snippets is
more natural for me. Many decades ago I did that using PL/I-80 on my
self-built CP/M computer, nowadays I just fire up a Python REPL, or
start a Jupyter notebook, for so called "back of the envelope"
calculations.

I do have a calculator app on my phone, which doesn't emulate anything.
It is switchable between traditional algebraic and RPN, radix modes
etc., though. The most frequently used feature is the comprehensive
conversion table for units, length, area, mass, speed and such. How
would I be able to convert Fathoms to Furlongs, without such a tool? :-)

Post by Jeff Liebermann
If we can become accustomed to QWERTY keyboards designed to
slow down typing, we can get used to anything. I can switch back and
forth between algebraic and RPN. Algebraic for financial calculations
and RPN for engineering. Evaluating long equations is easier (for me)
using RPN.

I can relate to that, but personally, I just don't calculate that way, I
don't do one shot calculations often enough to earn a benefit from RPN.

My first and only HP calculator is a HP 200LX, still working fine. I
lost one of the tiny case screws, decades ago, replacing the CR2032 now
and then is still awkward. I have no real use for the device anymore,
but I still like it enough for not giving it away. AFAIR, there's still
a copy of the original DeSmet C compiler on the flash card in the PCMCIA
slot. :-)

Getting back to cycling ... :-)

27 years ago, in 1998, the HP 200LX spent a lot of time in my panniers
on my commute (~5000 km/a). While playing with and exploring tiny
Microchip PIC microcontrollers at that time as a hobby, I used a spare
and slightly defective homebrew PCB (size ~1,3 *1,4 inch) as a prototype
board, took a PC16C84 processor, a 4,194,304 Hz quartz, 3 small
capacitors, one resistor, a 9 pin RS232 connector and two sockets, in
order to build an interface between the HPLX200 and a standard reed
contact as used by most bicycle computers sold at that time.

For simplicity, I didn't implement anything fancy on the PIC, by just
measuring and counting revolutions for an adjustable time span and then
sending the data in plain ASCII via the standard null modem cable which
came with the 200LX, leaving collecting the data and perhaps doing the
calculations on the 200LX.

I worked quite well, for some definition of "well". As often, software
and electronics were not the problem. The mechanics were the problem,
more precisely, the proprietary cable from the HP to my circuit board.
So in the end, I just collected data from a single test drive by using
the log feature of the 200LXs terminal program, while carefully holding
the plug with one hand, transfered that to a PC, used Excel to produce a
table - and finally admired my work. :-)

*** from PIC *******
One Revolution s
Current speed km/s
Accum. rev #
Distance km
Time s
800 6 2531 0,62 12,5 6 0,013 50
880 9 1867 0,46 17 15 0,032 55
960 16 1174 0,29 27 31 0,067 60
1040 19 1123 0,27 28,2 50 0,108 65
1120 17 1186 0,29 26,7 67 0,144 70
1200 16 1238 0,3 25,6 83 0,178 75
1280 15 1311 0,32 24,2 98 0,211 80
1360 14 1400 0,34 22,6 112 0,241 85
1440 14 1374 0,34 23,1 126 0,271 90
1520 17 1209 0,3 26,2 143 0,307 95
1600 16 1309 0,32 24,2 159 0,342 100
1680 15 1426 0,35 22,2 174 0,374 105
1760 14 1458 0,36 21,7 188 0,404 110
1840 14 1474 0,36 21,5 202 0,434 115
1920 14 1456 0,36 21,8 216 0,464 120
2000 14 1455 0,36 21,8 230 0,495 125
2080 15 1432 0,35 22,1 245 0,527 130
2160 14 1450 0,35 21,9 259 0,557 135
2240 14 1461 0,36 21,7 273 0,587 140
2320 14 1471 0,36 21,6 287 0,617 145
2400 14 1560 0,38 20,3 301 0,647 150

Anyway, having worked exclusively with mainframes in my job during the
early years, followed by PC sized smaller computers connected to what
they call "cloud" these days, I developed an interest in tiny
microcontrollers that were actually simple and useable for a hobbyist.
This started with the early PIC from Microchip, still expensive, needing
expensive UV-erasable versions, followed by the PIC 18C84 EEPROM
version, which could be reprogrammed without needing an somewhat
expensive UV lamp. Even more joy was using much smaller 8 bit
controllers that were still able to do work that what would have needed
a lot of TTL logic, beforehand. Like for example the PIC10F200
<https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/40001239F.pdf>
Harvard architecture, DIP8, 4 MHz, 256 words program memory, 16 Bytes
RAM, 3 I/O pins, one Input only pin, internal pullups, serial
programmable using an inexpensive programmer. One doesn't need an ARM
CPU with a handfull of cores in order to operate a mid sized toy
railroad, a handfull of these tiny and cheap microcontrollers would do,
at least in principle.

There are cheaper microcontrollers of Chinese origin, Padauk comes to
mind. A quick search tells the there are still cheaper ones in the
pipeline (1.5 cents for a complete computer, wow!)
<https://zeptobars.com/en/read/Nyquest-Technology-NY8A051H-8051-smallest-microcontroller>
but frankly, that's something for the next generation to play with. Is
it possible to implement Tetris with 1k words of OTP memory and 48 bytes
of SRAM? What about a Mastermind solver? I implemented a
Mastermind/Bulls&Cows solver using the PIC16C84, complete with decoding
two buttons, driving/multiplexing a raw four-digit seven-segment
display, using most of its 2 K words of EEPROM and 68 bytes of RAM.

<https://www.mystrobl.de/ws/pic/mm47/>

Parts are still available in 2025, including PIC 16F84A (€6.30 at a
local dealer) and HDSP 5503 (between 4 and 8 $ at ebay), so building
that gadget would still be possible. Rather uninteresting, though,
because microelectronics came a long way between the 16C84 and what we
can use buy and even as hobbyists, today.

This makes me reflect on the criticism of electronics in bicycles. I'm
not talking about replacing muscle power by motor power, that's
replacing bicycles by something else. But what about measuring the
amount of power applied to the pedals, what about telling the cyclist
who balanced he splits the power between left and right, by
instrumenting the pedal or the bottom bracket? What about replacing
those awkward cables and complicated brifters with simple electric
switches and an encrypted wireless channel? Is that bad, because a
blacksmith can't repair it with his tools, like giving a horse a new
pair of horse shoes? What about LED lights, then? Shouldn't we get
back to incandescent bulbs, powered by bottle dynamos?

I think we should not and can not turn back the wheel, at least not like
this. I accept that there are reasons to keep bicycles simple, or to
keep at least some biycles simple enough to long lived and usable even
without much maintenance and without exotic stuff. But the question is,
what makes a component or material exotic? Is a specific bowden cable or
a gear hub or hub generator really less exotic and simpler to
replace/recreate than, say, a LED light or a wireless shifter? I doubt
it.

There is a point when mechanical parts become complicated enough to
create a vendor lock-in, when a second source isn't available. Just like
with electronic parts. Sometimes the relationship gets reversed, when an
over-engineered and complicated mechanical solution is replaced by a
simple construction that combines commercially available electronics
with simple mechanical parts.

In this respect, you have to take a close look at where a dependency
arises, instead of simply linking it to characteristics such as “new”,
“electronic” or “wireless”. We need open standards, either through
industry commitments, or by regulations.

--
Thank you for observing all safety precautions

Frank Krygowski

2025-01-11 01:01:26 UTC

This makes me reflect on the criticism of electronics in bicycles. ... But what about measuring the
amount of power applied to the pedals, what about telling the cyclist
who balanced he splits the power between left and right, by
instrumenting the pedal or the bottom bracket?

Yes, that can be done with enough sensors and electronics. But it seems
like useless information to me. As with much computer software, it seems
like "feature bloat." Why would anybody but a racer care?

What about replacing
those awkward cables and complicated brifters with simple electric
switches and an encrypted wireless channel? Is that bad, because a
blacksmith can't repair it with his tools, like giving a horse a new
pair of horse shoes?

Of course, you're welcome to use electric shifting if you like. (Or
brifters, which I don't!) But my life experience with electronic devices
makes me suspicious. I've seen too many examples of electronic devices
that simply stopped working, with no possible way of diagnosing the
problem - at least, not by me. And while I'm far from an electronics
expert, I'm better than the average citizen.

Two days ago, my kid asked me to figure out why an electric blanket
wasn't working. The controller refused to turn on. I opened it and
confirmed that it was getting supply voltage. Beyond that, the pile of
dozens of surface mount electronic components was incomprehensible to
me. I suspect Jeff might have been able to diagnose it, but not me.
Here's a photo:
https://www.flickr.com/photos/***@N08/54259119364/in/dateposted-public/
I know electric blankets are old technology. I know they functioned well
for decades with maybe a rheostat and perhaps a couple of other
components. Why add unrepairable complexity?

Similarly, a good friend recently told me about her adventure with her
relatively new washing machine. During an expensive service visit, a
repairman told her the problem was somewhere in the main circuit board,
and that the only solution was to replace the expensive board. Our
washer is something like 35 years old, uses an electro-mechanical timer,
and will probably work well for whichever grandkid inherits it.

I'm positive my shifters are also going to be working for whichever
grandkid inherits them. I wouldn't be confident about electronic shifters.

What about LED lights, then? Shouldn't we get
back to incandescent bulbs, powered by bottle dynamos?

I love good LED bike lights. And in some cases, the LEDs are direct
replacements for incandescent bulbs. But I still use bottle dynos on two
bikes. They can be more than fine, depending on service requirements.

I think we should not and can not turn back the wheel, at least not like
this. I accept that there are reasons to keep bicycles simple, or to
keep at least some biycles simple enough to long lived and usable even
without much maintenance and without exotic stuff. But the question is,
what makes a component or material exotic? Is a specific bowden cable or
a gear hub or hub generator really less exotic and simpler to
replace/recreate than, say, a LED light or a wireless shifter? I doubt
it.

It depends on the LED light, I suppose. Some seem to have on board
electronics as complicated as that blanket controller, and I don't know
why. (I am curious about that, having opened up one Busch & Muller
headlamp.) But I've opened and repaired both gear hubs and hub dynos
from the 1950s. They now work perfectly. That won't be true of current
electronic shifters 50 years from now.

--
- Frank Krygowski

zen cycle

2025-01-11 05:06:46 UTC

This makes me reflect on the criticism of electronics in bicycles. ...
But what about measuring the
amount of power applied to the pedals, what about telling the cyclist
who balanced he splits the power between left and right, by
instrumenting the pedal or the bottom bracket?

One doesn't need to be a racer to be interested in those types of
metrics. I know plenty of "former" racers, and "sport" cyclists that
keep diligent track of their workouts.

I'm no fan of electronic shifting - it would be just my luck to be on
planed 4-6 hour ride, and have something crap out at the furthest point
from the car/house. That said, I'm never going back to discrete shifters.

Post by Frank Krygowski
Two days ago, my kid asked me to figure out why an electric blanket
wasn't working. The controller refused to turn on. I opened it and
confirmed that it was getting supply voltage. Beyond that, the pile of
dozens of surface mount electronic components was incomprehensible to
me. I suspect Jeff might have been able to diagnose it, but not me.
public/
I know electric blankets are old technology. I know they functioned well
for decades with maybe a rheostat and perhaps a couple of other
components. Why add unrepairable complexity?

Becasue it's quite a bit cheaper to produce, and generally works just as
well.

Post by Frank Krygowski
Similarly, a good friend recently told me about her adventure with her
relatively new washing machine. During an expensive service visit, a
repairman told her the problem was somewhere in the main circuit board,
and that the only solution was to replace the expensive board. Our
washer is something like 35 years old, uses an electro-mechanical timer,
and will probably work well for whichever grandkid inherits it.
I'm positive my shifters are also going to be working for whichever
grandkid inherits them.

I'm just as optimistic about my Sram integrated system, but the idea
that they would see anything a=of value in my collection of bikes...I'm
kinda skeptical about.

Wolfgang Strobl

2025-01-11 21:22:07 UTC

Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

Post by zen cycle
I'm no fan of electronic shifting - it would be just my luck to be on
planed 4-6 hour ride, and have something crap out at the furthest point
from the car/house. That said, I'm never going back to discrete shifters.

It isn't that difficult to carry a CR2032 and a tiny 25 g rechargeable
battery somewhere. The coin cell lasts about two years, the battery is
good for about 800-1000 km. Both warn early via LED on the device or via
a Garmin Edge computer, for not having to care during a 4-6 hour ride.

--
Thank you for observing all safety precautions

Frank Krygowski

2025-01-12 00:47:52 UTC

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

But how many threads have we had here about problems with Garmin computers?

--
- Frank Krygowski

Catrike Ryder

2025-01-12 09:33:25 UTC

On Sat, 11 Jan 2025 19:47:52 -0500, Frank Krygowski

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

But how many threads have we had here about problems with Garmin computers?

Not so many. I did have the Garmin Edge 130+ computer fail, but I
don't recall any other Garmin computer failures reported.

I also have a Garmin Edge 500 that I bought in 2011 and retired in
2023 that still works perfectly. I upgraded to get some additional
features. My wife uses it currently on her Catrike Pocket which is
inside on rollers.

--
C'est bon
Soloman

Wolfgang Strobl

2025-01-12 14:54:52 UTC

Am Sat, 11 Jan 2025 19:47:52 -0500 schrieb Frank Krygowski

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

But how many threads have we had here about problems with Garmin computers?

Don't know. My Garmin GPSMap 60CSx
<Loading Image...

>
that I bought in early 2008 is still working, but I replaced it by a
better version (a 64 s), when this was sold at a very low price, in
2018. I still use it as an outdoor device, when walking or for just
recording a track on a long car ride. Can't report real problems when
using an EDGE 1030 plus, so far, because I haven't had none.

By the way, before it gets lost, while it is indeed convenient to be
warned about low battery by the Garmin 1030, it isn't necessary for
checking battery state. Both shifters display the state, when activated
(full, low, critical), and so does the derailleur. In both cases, low is
signaled early enough to still have about a day of riding left.

There _are_ problems with devices like that, just with any new
technology. But these aren't. Our bikes and their wireless shifting is
perfectly useable without a Garmin computer, or a similar device of
another brand.

In my home town, I see many cyclists riding around on almost flat rear
tires. This is somewhat dangerous. New cars have obligatory tire
pressure warning, for quite some time. Most of these need maintenance,
costing money. Such devices exist for bicycles, too. One of our sons
used such a device on his bike, out of curiosity. It caused more
problems than it solved, so he dismantled it.

I fear that some fool comes up with the idea of making such a
montitoring device mandatory for bicycles, too, perhaps by pointing to
modern bicycles, ahem, to E-Bikes. :-/ We can't be safe enough, right?
Right? :-)

--
Thank you for observing all safety precautions

Roger Merriman

2025-01-12 18:36:56 UTC

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

But how many threads have we had here about problems with Garmin computers?

99.9% are from one poster…

It’s a Him thing, Garmin/Wahoo/Hammerhead stuff is fairly mature tech now
and on the whole just works.

I have the same unit as him and unsurprisingly it hasn’t caused me any
problems!

Roger Merriman

zen cycle

2025-01-12 12:22:01 UTC

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

I can't tell you how many times I leave the house and forget my wallet.
Adding trying to remember to carry a spare battery is only part of the
problem though.

The other issue is the failure rates associated with a complex
electro-mechanical systems VS a simple cable derailleur system. (Since I
conduct FMEDAs as part of my role, I'm well-aware of the exponential
failure rates associated with increased complexity).

Since I've been seriously riding in the early 1980's, I've never had a
problem associated with a shifting mechanism that I couldn't handle with
a simple road/trail side repair, except for the few times when I've
sheared the derailleur off in the woods. If your E-shifting mechanism
fails for any reason other than the battery going dead, you're pretty
much stick in whenever gear it left you in.

I don't begrudge anyone for wanting E-shifting. I think it's a great
technological advancement. The few times I've ridden E-shifting systems,
I've been impressed with the accuracy, repeatability, and quickness of
the shifts. But I don't see those advantages of being worth the extra
cost and risk of failure. That's just my opinion, YMMV.

AMuzi

2025-01-12 17:30:44 UTC

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

Post by zen cycle
I'm no fan of electronic shifting - it would be just my
luck to be on
planed 4-6 hour ride, and have something crap out at the
furthest point
from the car/house. That said, I'm never going back to
discrete shifters.

It isn't that difficult to carry a CR2032 and a tiny 25 g
rechargeable
battery somewhere. The coin cell lasts about two years,
the battery is
good for about 800-1000 km. Both warn early via LED on the
device or via
a Garmin Edge computer, for not having to care during a
4-6 hour ride.

I can't tell you how many times I leave the house and forget
my wallet. Adding trying to remember to carry a spare
battery is only part of the problem though.
The other issue is the failure rates associated with a
complex electro-mechanical systems VS a simple cable
derailleur system. (Since I conduct FMEDAs as part of my
role, I'm well-aware of the exponential failure rates
associated with increased complexity).
Since I've been seriously riding in the early 1980's, I've
never had a problem associated with a shifting mechanism
that I couldn't handle with a simple road/trail side repair,
except for the few times when I've sheared the derailleur
off in the woods. If your E-shifting mechanism fails for any
reason other than the battery going dead, you're pretty much
stick in whenever gear it left you in.
I don't begrudge anyone for wanting E-shifting. I think it's
a great technological advancement. The few times I've ridden
E-shifting systems, I've been impressed with the accuracy,
repeatability, and quickness of the shifts. But I don't see
those advantages of being worth the extra cost and risk of
failure. That's just my opinion, YMMV.

Modern electronic shift systems work. They're different from
mechanical but IMHO neither better nor worse, just different.

https://pezcyclingnews.com/technspec/how-i-survived-a-dead-sram-etap-battery/

https://www.reddit.com/r/cycling/comments/p0vxtq/shimano_di2_options_when_battery_dies_mid_trip/

"One temporary solution would be to find someone that has a
Di2, unplug their and your rear derailleur and plug in their
cable into your derailleur. You can then change to the
comfortable gear and ride back home. "

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

zen cycle

2025-01-12 17:55:26 UTC

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

I can't tell you how many times I leave the house and forget my
wallet. Adding trying to remember to carry a spare battery is only
part of the problem though.
The other issue is the failure rates associated with a complex
electro-mechanical systems VS a simple cable derailleur system. (Since
I conduct FMEDAs as part of my role, I'm well-aware of the exponential
failure rates associated with increased complexity).
Since I've been seriously riding in the early 1980's, I've never had a
problem associated with a shifting mechanism that I couldn't handle
with a simple road/trail side repair, except for the few times when
I've sheared the derailleur off in the woods. If your E-shifting
mechanism fails for any reason other than the battery going dead,
you're pretty much stick in whenever gear it left you in.
I don't begrudge anyone for wanting E-shifting. I think it's a great
technological advancement. The few times I've ridden E-shifting
systems, I've been impressed with the accuracy, repeatability, and
quickness of the shifts. But I don't see those advantages of being
worth the extra cost and risk of failure. That's just my opinion, YMMV.

Modern electronic shift systems work. They're different from mechanical
but IMHO neither better nor worse, just different.

Which is why I wrote "The few times I've ridden E-shifting systems, I've
been impressed with the accuracy, repeatability, and quickness of the
shifts. "

https://pezcyclingnews.com/technspec/how-i-survived-a-dead-sram-etap-
battery/
https://www.reddit.com/r/cycling/comments/p0vxtq/
shimano_di2_options_when_battery_dies_mid_trip/
"One temporary solution would be to find someone that has a Di2, unplug
their and your rear derailleur and plug in their cable into your
derailleur. You can then change to the comfortable gear and ride back
home. "

Frank Krygowski

2025-01-12 19:36:27 UTC

Post by AMuzi
https://www.reddit.com/r/cycling/comments/p0vxtq/
shimano_di2_options_when_battery_dies_mid_trip/
"One temporary solution would be to find someone that has a Di2, unplug
their and your rear derailleur and plug in their cable into your
derailleur. You can then change to the comfortable gear and ride back
home. "

From the comments there: "My wireless 12speed di2 dies after roughly 2
weeks."

Yow!

And plenty of copies of "Just charge your batteries frequently!"

No thanks. I don't even want to have to think about headlamp batteries.

--
- Frank Krygowski

Catrike Ryder

2025-01-12 20:00:58 UTC

On Sun, 12 Jan 2025 14:36:27 -0500, Frank Krygowski

From the comments there: "My wireless 12speed di2 dies after roughly 2
weeks."
Yow!
And plenty of copies of "Just charge your batteries frequently!"
No thanks. I don't even want to have to think about headlamp batteries.

Relax. Nobody going tio make you use one.

--
C'est bon
Soloman

Wolfgang Strobl

2025-01-12 18:49:40 UTC

Am Sun, 12 Jan 2025 07:22:01 -0500 schrieb zen cycle

Post by Wolfgang Strobl
Am Sat, 11 Jan 2025 00:06:46 -0500 schrieb zen cycle

I can't tell you how many times I leave the house and forget my wallet.
Adding trying to remember to carry a spare battery is only part of the
problem though.

This is a bit like comparing apples and oranges, though. After having
left my house key behind once, I learned my lesson, I just check having
the correct key, before closing the door, every time.

I don't check batteries, when doing a day trip, simply because

- the Edge 1030 does that for me
- I would recharge the rechargeable batteries, before doing a multi
day trip
- I can't forget the batteries, because I carry spares in a bag that
stays on the bike.
- I carry a phone and enough money on my local trips in order to be
able to call a taxi to take me and the bike home.

See <Loading Image...

>,
the bag on the top tube is screwed to the top tube.

So there isn't really anything special to remember. I carry some
minature tools, too, a TPU tube, just in case. It is a sortiment that
gets adjusted depending on circumstances, but rarely. YMMV.

Checking and carrying one one of my cameras is more of a hassle. The
SD-Card has to be emptied, sometimes. The batterie has to be checked and
charged. But I carry a spare one for the camera, too.

Post by zen cycle
The other issue is the failure rates associated with a complex
electro-mechanical systems VS a simple cable derailleur system. (Since I
conduct FMEDAs as part of my role, I'm well-aware of the exponential
failure rates associated with increased complexity).

Problem is, you don't have reliable and useable statistics, neither for
cables nor for wireless shifters. So this is still just guesswork.
Admiring the simple construction of a Bowden cable won't help you if
you're stranded far out with a broken cable and don't have a
replacement. Or if the highly complex inner workings of a mechanical
gearshift handle that is no longer sold have become defective. I
experienced both, in the past.

Post by zen cycle
Since I've been seriously riding in the early 1980's, I've never had a
problem associated with a shifting mechanism that I couldn't handle with
a simple road/trail side repair, except for the few times when I've
sheared the derailleur off in the woods.

Actually, my wife would have stranded last year somewhere in the middle
of nowhere, if we wouldn't have done the tour together. So I cycled the
ten or twenty kilometers back to our accommodation, got into the car,
drove back and loaded the bike into the trunk.

What happened? Well, the saddle clamp broke. As it turned out, the clamp
included by the frame supplier for her bike was a cheap lemmon. It is
almost impossible to ride up a steep hill without a saddle. The clamp on
my bike was fine. But of course, I replaced both clamps, before riding
again. I was quite annoyed that I didn't inspect the seat clamps more
closely when I built the bikes. Lesson learned ...

THe saddle clamp is almost the simplest mechanical part of a bike that I
can think of.

Post by zen cycle
If your E-shifting mechanism
fails for any reason other than the battery going dead, you're pretty
much stick in whenever gear it left you in.

Not true. It is possible to shift in both directions by pushing a tiny
button on the derailleur. Good enough to get home. Doing something
similar with a broken Bowden cable is possible, but difficult. I doubt
that your average cyclist can do it.

It happended with the purely mechanical shifter on my former bicycle,
that part broke beyond repair, without warning, during the last ride
before our yearly vacation. Just by luck, I found a dealer who still had
a replacement in stock, so that I got the bike back one day before
departure.

I wouldn't use consider wireless shifting on a bike intended for a trip
around the world or through a developing country. But I wouldn't use
most of what has been sold during the past three decades as a purely
mechanical system, either.

Post by zen cycle
I don't begrudge anyone for wanting E-shifting. I think it's a great
technological advancement. The few times I've ridden E-shifting systems,
I've been impressed with the accuracy, repeatability, and quickness of
the shifts. But I don't see those advantages of being worth the extra
cost and risk of failure.

Extra cost is a thing, indeed. But that will change. Small actuators,
tiny CPUs and ANT+/BLE variants aren't rocket science or really new,
anymore. IMO, a reliable E-shifting system like those currently sold by
Shimano and SRAM could be built to be both more reliable and cheaper
than their older mechanical counterparts (say Shimano R8000). Fewer
mechanical parts, even fewer electronic parts with a known MTBF would
allow that. Given that we a surrounded by long lived electronic devices
that are far more complex than these very simple E-Shifting systems, it
needs really bad luck or bad intentions to make them short-lived.
Actually, it is a wonder that modern cars don't break shortly after
leaving the factory. :-) And of course, I don't know how reliable those
electronic parts from SRAM and Shimano really are. But I know that some
mechanical shifters from Shimano are less reliable than I like.

Post by zen cycle
That's just my opinion, YMMV.

Sure. :-) So far, most of this is just guesswork. Wait and see ...

--
Thank you for observing all safety precautions

Frank Krygowski

2025-01-12 20:03:40 UTC

Post by Wolfgang Strobl
- I can't forget the batteries, because I carry spares in a bag that
stays on the bike.

That's my philosophy with every bike. No batteries for me, but each bike
has its own patch kit, tool kit, spare tube, etc. in a handlebar bag or
seat bag.

Two of the bikes (my touring bike and tandem) also have spare shift
cables, because they require unusually long cables. Also, since the
1970s I leave a few inches of extra cable looped beyond the derailleur
cable clamp. Cables break at the shifter, which for me are simple
bar-ends. I've fed the extra cable back through the shifter and knotted
it to replace the button end.

Post by Wolfgang Strobl
Admiring the simple construction of a Bowden cable won't help you if
you're stranded far out with a broken cable and don't have a
replacement.

See above! ;-)

Post by Wolfgang Strobl
Or if the highly complex inner workings of a mechanical
gearshift handle that is no longer sold have become defective. I
experienced both, in the past.

That's why I prefer bar-ends. Some index, mostly friction.

Post by Wolfgang Strobl
I wouldn't use consider wireless shifting on a bike intended for a trip
around the world or through a developing country.

There are many parts of the U.S. that are as isolated as a developing
country. My first ride across Ohio, west to east, began on Labor Day
weekend 1987. The towns were very few and far between, and everything
was closed for the holiday. We had great trouble finding a place that
would serve us food! Riding across Pennsylvania (east to west) was
similar at times, especially through the Appalachians.

--
- Frank Krygowski

Jeff Liebermann

2025-01-12 19:03:13 UTC

On Sun, 12 Jan 2025 07:22:01 -0500, zen cycle

Post by zen cycle
I can't tell you how many times I leave the house and forget my wallet.
Adding trying to remember to carry a spare battery is only part of the
problem though.

I had the same problem. My solution was to put a cardboard box near
the door that contains everything I plan to take with me for the day,
including my wallet and TWO car keys. When I leave the house, I only
need to remember to either fill my pockets with the contents of the
box or just take the box with me. If I don't do that, trying to
remember what I need to take with me in the morning is failure prone
(if not futile). I've been using this system successfully for about
30 years. The only times this system fails is when I do something
impulsive.

I have a similar cardboard box in my car for stuff that needs to be
dragged into the house. When I still had my former palatial office, I
also put a box near the office door.

If you're planning on going for a ride, you probably will have done
some planning the previous day. Instead of trying to remember to
bring a spare battery, just throw it in the box.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

Frank Krygowski

2025-01-12 19:37:13 UTC

... I'm well-aware of the exponential failure
rates associated with increased complexity.

Exactly!

--
- Frank Krygowski

Wolfgang Strobl

2025-01-11 21:11:57 UTC

Am Fri, 10 Jan 2025 20:01:26 -0500 schrieb Frank Krygowski

Is there any reason to believe that old people like me don't have a need
to care about training intensity, as a matter of principle? How comes?

When using my biycles as a middle aged, healthy adult I didn't care
about racing, didn't train and didn't try to find company in cycling
clubs, either. I didn't visit a gym until much later. Cycling was simply
a way to get to work quickly. During vacations it was a more
entertaining mode of transportation than the car. Fitness, strength and
cardio fitness came as a side effect, slowly and almost unnoticed.

This has changed. My cardio fitness is still better than what I know
about a lot of people half my age. Nevertheless, it decreased over the
years and it takes more and more effort to keep what you have not yet
lost. As it is expected. The ability to measure power is helpful in
finding the point at which intensity is sufficient and overload has not
yet begun. This is even more true in combination with a heart rate
monitor.

So far, this is only about aging. But there is more.

Accidents that led to damage to bones, joints and tendons in the past
have consequences to be considered, too. There is a tendency to
compensate weaknesses by bad postures, whithout noticing. This is both
caused by damages and causing damages. This is to be avoided. Measuring
how power is applied by the feet helps detecting differences early,
avoiding damage.

Avoiding damage is far from useless.

Of course, you're welcome to use electric shifting if you like.

Thank you very much. :-)
(Or

Post by Frank Krygowski
brifters, which I don't!) But my life experience with electronic devices
makes me suspicious. I've seen too many examples of electronic devices
that simply stopped working, with no possible way of diagnosing the
problem - at least, not by me. And while I'm far from an electronics
expert, I'm better than the average citizen.

Live and learn.

My experiences with mechanical devices are at least as mixed as those
with electronic devices. Some very complicated electronic devices that
I bought decades ago still work. The same applies to some that I built
myself a long time ago. With devices that contained both electronic and
mechanical parts, the fault was more often on the mechanical side.

Anecdotical, I know.

Post by Frank Krygowski
Two days ago, my kid asked me to figure out why an electric blanket
wasn't working. The controller refused to turn on. I opened it and
confirmed that it was getting supply voltage. Beyond that, the pile of
dozens of surface mount electronic components was incomprehensible to
me. I suspect Jeff might have been able to diagnose it, but not me.
I know electric blankets are old technology. I know they functioned well
for decades with maybe a rheostat and perhaps a couple of other
components. Why add unrepairable complexity?

Don't know. We use devices like the blue one in the following picture.
<Loading Image...

>
and better isolating blankets. No electricity necessary. :-)

A few lights in our house are switched by set of 2 x 3 inexpensive
wireless sockets including two remote controls, that I bought eleven
years ago. I've still to replace the batteries. Two of the sockets are
still spares, I have a replacement cell for the remote controls stored
which might live even longer. Standard type, used in garage openers and
burglar alarms, too. Selecting a channel and paring one of the four
buttons of a remote control with one or more of the sockets is as easy
as pie, using a line of dip switches inside those devices. Quite
similar to pairing switches and derailleur on our bicyles.

While I avoid having essential functionality in my house depend on
wireless connections, I enjoy having the option, for certain use cases,
though. Same with bicycles.

I can relate to that, up to a point. A lot of our equipment is or was
of similar age, or even older. Had a similar experience with our oven,
when it was ten years and a month old. Error code xyz, "call service".
Expensive service visit by NEFF, proposed solution was replacing thre
expensive boards one after the other, without any guarantee. Almost as
expensive as a new oven. Refused, payed the service, decided not to buy
anything from NEFF again and tried the repair myself. Found a pair of
cold solder joints just before the heating coil causing some protection
circuit to trigger, resoldered. Problem solved. Wondered why a cold
joint took so long to break, then remembered having replaced the heating
coil years ago because of intermittent problems. Most probably, I
replaced a working heating coil, accidently somehow fixing the
connection, perhaps just by moving the oven out of his compartement. I'm
still using that oven for baking bread every two or three day.

On the other hand, while I won't enjoy having to replace our old washing
machine and the dryer, I know that new machines are a lot more efficent.
Dryers produce water instead of releasing hot steam, washing machines
spin the loundry much faster, etc.

Post by Frank Krygowski
I'm positive my shifters are also going to be working for whichever
grandkid inherits them. I wouldn't be confident about electronic shifters.

I still have some carpentry tools which where already old before I was
born. I don't throw them away out of respect, but don't use any of
these.

In a world where people get rid of cars when the are a few years old, I
don't see a point in conserving antique bicyles for later generations.
Not for _using_ these bicycles, that is. I'm quite confident that it is
easier to make a electronic derailleur outlive the bicycle than doing
that with a mechanical one. Don't know about actual product, though. I
have my doubts about the shifter, though. Guess what: it is a mechanical
problem. Replacing the CR2032 without damaging the contacts is a
mechanical problem. Cold be solved by a better mechanical solution, but
not by me.

What about LED lights, then? Shouldn't we get
back to incandescent bulbs, powered by bottle dynamos?

I love good LED bike lights. And in some cases, the LEDs are direct
replacements for incandescent bulbs.

Eeek. I'd rather have a LED built into a well designed free form
reflector.

Post by Frank Krygowski
But I still use bottle dynos on two
bikes. They can be more than fine, depending on service requirements.

Sure. Exceptions from the rule are to be expected.

It depends on the LED light, I suppose. Some seem to have on board
electronics as complicated as that blanket controller,

So what. At a certain point electronics just are components. You
wouldn't repair a halogen bulb, either. I don't care about how
complicated an electronic board is, I care about its MTBF.

Post by Frank Krygowski
and I don't know
why. (I am curious about that, having opened up one Busch & Muller
headlamp.) But I've opened and repaired both gear hubs and hub dynos
from the 1950s. They now work perfectly. That won't be true of current
electronic shifters 50 years from now.

I broke two gear hubs in sequence, didn't repair either one myself,
because I didn't have time for that, because of job, family and the time
needed for a long commute by bike. First one broken beyond repair,
according to the shop, I learned to live with a missing gear with the
second one. Bicycles are tools which wear out both through use and
technological progress. A lot sold as progress is just fashion. But
sometimes, a change is progress. I like having choices.

When I see a 50 year old, perfect looking bicycle, I think:
That one must have been standing around inside most of the time, perhaps
for a reason. There actually is such a bicycle in our family, a local
shop built it for my wife, long ago. Served its purpose, it is not
nearly as old, but old and nice enough to find a place to hang it on the
wall. But taking it for a ride? Perhaps, for riding to a nearby ice
cream parlor during summer. :-)

--
Thank you for observing all safety precautions

Frank Krygowski

2025-01-12 00:46:50 UTC

Post by Wolfgang Strobl
Am Fri, 10 Jan 2025 20:01:26 -0500 schrieb Frank Krygowski

Is there any reason to believe that old people like me don't have a need
to care about training intensity, as a matter of principle? How comes?
When using my biycles as a middle aged, healthy adult I didn't care
about racing, didn't train and didn't try to find company in cycling
clubs, either. I didn't visit a gym until much later. Cycling was simply
a way to get to work quickly. During vacations it was a more
entertaining mode of transportation than the car. Fitness, strength and
cardio fitness came as a side effect, slowly and almost unnoticed.
This has changed. My cardio fitness is still better than what I know
about a lot of people half my age. Nevertheless, it decreased over the
years and it takes more and more effort to keep what you have not yet
lost. As it is expected. The ability to measure power is helpful in
finding the point at which intensity is sufficient and overload has not
yet begun. This is even more true in combination with a heart rate
monitor.
So far, this is only about aging. But there is more.
Accidents that led to damage to bones, joints and tendons in the past
have consequences to be considered, too. There is a tendency to
compensate weaknesses by bad postures, whithout noticing. This is both
caused by damages and causing damages. This is to be avoided. Measuring
how power is applied by the feet helps detecting differences early,
avoiding damage.
Avoiding damage is far from useless.

But individual power outputs from left and right legs? I can't imagine
much value from that measurement. In fact, I don't believe power
measurement is necessary for fitness. I judge by feel. It has the
advantage of naturally compensating for days when I feel stronger or
weaker. And it's organic! ;-)

Post by Wolfgang Strobl
My experiences with mechanical devices are at least as mixed as those
with electronic devices. Some very complicated electronic devices that
I bought decades ago still work. The same applies to some that I built
myself a long time ago. With devices that contained both electronic and
mechanical parts, the fault was more often on the mechanical side.
Anecdotical, I know.

To me, a big advantage is the ability to _look_ at a mechanical device
and _see_ what's wrong. That, and the fact I can often affect a repair.
I hate the Kleenex ethic - "It's no good any more, just throw it away."

Post by Wolfgang Strobl

Post by Frank Krygowski
Two days ago, my kid asked me to figure out why an electric blanket
wasn't working. The controller refused to turn on. I opened it and
confirmed that it was getting supply voltage. Beyond that, the pile of
dozens of surface mount electronic components was incomprehensible to
me. I suspect Jeff might have been able to diagnose it, but not me.
I know electric blankets are old technology. I know they functioned well
for decades with maybe a rheostat and perhaps a couple of other
components. Why add unrepairable complexity?

Don't know. We use devices like the blue one in the following picture.
<https://upload.wikimedia.org/wikipedia/commons/4/4b/W%C3%A4rmflasche1.jpg>
and better isolating blankets. No electricity necessary. :-)

:-) But you imply that _I'm_ the one insufficiently modern?

Post by Wolfgang Strobl
A few lights in our house are switched by set of 2 x 3 inexpensive
wireless sockets including two remote controls, that I bought eleven
years ago. I've still to replace the batteries. Two of the sockets are
still spares, I have a replacement cell for the remote controls stored
which might live even longer. Standard type, used in garage openers and
burglar alarms, too. Selecting a channel and paring one of the four
buttons of a remote control with one or more of the sockets is as easy
as pie, using a line of dip switches inside those devices. Quite
similar to pairing switches and derailleur on our bicyles.
While I avoid having essential functionality in my house depend on
wireless connections, I enjoy having the option, for certain use cases,
though.

Yuck.

I bought a new pedestal fan for our back patio last year. I've found a
fan to be the best defense against mosquitos. The previous one still
runs, but exposure to sunlight destroyed its plastic finger protection
screen.

Anyway, the new one comes with a remote control, roughly the size of a
snack cracker. Who needs a remote to adjust a fan? I rejected ceiling
fans with remotes when I was shopping, too. It's something to lose,
something whose battery will die, and something whose electronics will
go bad and be unrepairable.
...

Post by Wolfgang Strobl
That one must have been standing around inside most of the time, perhaps
for a reason.

My favorite bike is a young 39 years. It looks perfect, in part because
I had it (and my wife's matching one) stripped and powder coated a
couple years ago. Too many excellent memories to let it go.

--
- Frank Krygowski

zen cycle

2025-01-12 12:49:31 UTC

Post by Wolfgang Strobl
Am Fri, 10 Jan 2025 20:01:26 -0500 schrieb Frank Krygowski

Post by Wolfgang Strobl
This makes me reflect on the criticism of electronics in
bicycles. ... But what about measuring the
amount of power applied to the pedals, what about telling the cyclist
who balanced he splits the power between left and right, by
instrumenting the pedal or the bottom bracket?

Is there any reason to believe that old people like me don't have a need
to care about training intensity, as a matter of principle? How comes?
When using my biycles as a middle aged, healthy adult I didn't care
about racing, didn't train and didn't try to find company in cycling
clubs, either. I didn't visit a gym until much later. Cycling was simply
a way to get to work quickly. During vacations it was a more
entertaining mode of transportation than the car. Fitness, strength and
cardio fitness came as a side effect, slowly and almost unnoticed.
This has changed. My cardio fitness is still better than what I know
about a lot of people half my age. Nevertheless, it decreased over the
years and it takes more and more effort to keep what you have not yet
lost. As it is expected. The ability to measure power is helpful in
finding the point at which intensity is sufficient and overload has not
yet begun. This is even more true in combination with a heart rate
monitor.
So far, this is only about aging. But there is more.
Accidents that led to damage to bones, joints and tendons in the past
have consequences to be considered, too. There is a tendency to
compensate weaknesses by bad postures, whithout noticing. This is both
caused by damages and causing damages. This is to be avoided. Measuring
how power is applied by the feet helps detecting differences early,
avoiding damage.
Avoiding damage is far from useless.

But individual power outputs from left and right legs? I can't imagine
much value from that measurement.

You answered your own question. "You" can't imagine it's useful. There
are a great many data geeks who find it quite useful.

Post by Frank Krygowski
In fact, I don't believe power
measurement is necessary for fitness. I judge by feel. It has the
advantage of naturally compensating for days when I feel stronger or
weaker. And it's organic! ;-)

In the exercise physiology world that's called Rate of Perceived
Exertion (RPE) and is an important factor, but it's vague, difficult to
assign any metric to, and only really detectable on a macro scale. If
you really want to improve fitness beyond just feeling better, you need
repeatable metrics with reasonable accuracy and resolution. RPE ain't it.

I agree with this to the extent that from a personal perspective I don't
see the added value. However, I fully support the development for those
that do find it useful.

Post by Wolfgang Strobl

Don't know. We use devices like the blue one in the following picture.
<https://upload.wikimedia.org/wikipedia/commons/4/4b/
W%C3%A4rmflasche1.jpg>
and better isolating blankets. No electricity necessary. :-)

:-) But you imply that _I'm_ the one insufficiently modern?

Yuck.
I bought a new pedestal fan for our back patio last year. I've found a
fan to be the best defense against mosquitos. The previous one still
runs, but exposure to sunlight destroyed its plastic finger protection
screen.
Anyway, the new one comes with a remote control, roughly the size of a
snack cracker. Who needs a remote to adjust a fan? I rejected ceiling
fans with remotes when I was shopping, too. It's something to lose,
something whose battery will die, and something whose electronics will
go bad and be unrepairable.
...

Post by Wolfgang Strobl
That one must have been standing around inside most of the time, perhaps
for a reason.

My favorite bike is a young 39 years. It looks perfect, in part because
I had it (and my wife's matching one) stripped and powder coated a
couple years ago. Too many excellent memories to let it go.

Or, if you're like me, I had my first racing bike fully restored, and
now it hangs in my hallway on display hooks with the fork crown at
eye-level. Some people really enjoy "bike porn":
https://veloclassics.blogspot.com/

Frank Krygowski

2025-01-12 19:25:37 UTC

Post by Frank Krygowski
But individual power outputs from left and right legs? I can't imagine
much value from that measurement.

You answered your own question. "You" can't imagine it's useful. There
are a great many data geeks who find it quite useful.

Maybe we can take a poll? How many here gather and use data on their
individual legs' power output?

--
- Frank Krygowski

AMuzi

2025-01-12 19:45:11 UTC

Post by Frank Krygowski
But individual power outputs from left and right legs? I
can't imagine much value from that measurement.

You answered your own question. "You" can't imagine it's
useful. There are a great many data geeks who find it
quite useful.

Maybe we can take a poll? How many here gather and use data
on their individual legs' power output?

If he finds it interesting, he ought to pursue it, even to
recording and manipulating the data (daily/weekly/monthly
averages, min-max differential and the like).

If you, as I, have no interest whatsoever, we shall not
acquire one.

As with so many discussions here, personal taste, for any
reason or for no reason, is reason enough for a decision
either way.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Catrike Ryder

2025-01-12 20:00:04 UTC

On Sun, 12 Jan 2025 14:25:37 -0500, Frank Krygowski

Post by Frank Krygowski
But individual power outputs from left and right legs? I can't imagine
much value from that measurement.

You answered your own question. "You" can't imagine it's useful. There
are a great many data geeks who find it quite useful.

Maybe we can take a poll? How many here gather and use data on their
individual legs' power output?

What would a poll of a bunch of old RBT geezers prove?

--
C'est bon
Soloman

AMuzi

2025-01-12 17:08:45 UTC

Post by Wolfgang Strobl
Am Fri, 10 Jan 2025 20:01:26 -0500 schrieb Frank Krygowski

Post by Wolfgang Strobl
This makes me reflect on the criticism of electronics in
bicycles. ... But what about measuring the
amount of power applied to the pedals, what about
telling the cyclist
who balanced he splits the power between left and right, by
instrumenting the pedal or the bottom bracket?

Yes, that can be done with enough sensors and
electronics. But it seems
like useless information to me. As with much computer
software, it seems
like "feature bloat." Why would anybody but a racer care?

Is there any reason to believe that old people like me
don't have a need
to care about training intensity, as a matter of
principle? How comes?
When using my biycles as a middle aged, healthy adult I
didn't care
about racing, didn't train and didn't try to find company
in cycling
clubs, either. I didn't visit a gym until much later.
Cycling was simply
a way to get to work quickly. During vacations it was a more
entertaining mode of transportation than the car. Fitness,
strength and
cardio fitness came as a side effect, slowly and almost
unnoticed.
This has changed. My cardio fitness is still better than
what I know
about a lot of people half my age. Nevertheless, it
decreased over the
years and it takes more and more effort to keep what you
have not yet
lost. As it is expected. The ability to measure power is
helpful in
finding the point at which intensity is sufficient and
overload has not
yet begun. This is even more true in combination with a
heart rate
monitor.
So far, this is only about aging. But there is more.
Accidents that led to damage to bones, joints and tendons
in the past
have consequences to be considered, too. There is a
tendency to
compensate weaknesses by bad postures, whithout noticing.
This is both
caused by damages and causing damages. This is to be
avoided. Measuring
how power is applied by the feet helps detecting
differences early,
avoiding damage.
Avoiding damage is far from useless.

But individual power outputs from left and right legs? I
can't imagine much value from that measurement. In fact, I
don't believe power measurement is necessary for fitness. I
judge by feel. It has the advantage of naturally
compensating for days when I feel stronger or weaker. And
it's organic! ;-)

Post by Wolfgang Strobl
My experiences with mechanical devices are at least as
mixed as those
with electronic devices. Some very complicated electronic
devices that
I bought decades ago still work. The same applies to some
that I built
myself a long time ago. With devices that contained both
electronic and
mechanical parts, the fault was more often on the
mechanical side.
Anecdotical, I know.

To me, a big advantage is the ability to _look_ at a
mechanical device and _see_ what's wrong. That, and the fact
I can often affect a repair. I hate the Kleenex ethic -
"It's no good any more, just throw it away."

Post by Wolfgang Strobl

Post by Frank Krygowski
Two days ago, my kid asked me to figure out why an
electric blanket
wasn't working. The controller refused to turn on. I
opened it and
confirmed that it was getting supply voltage. Beyond
that, the pile of
dozens of surface mount electronic components was
incomprehensible to
me. I suspect Jeff might have been able to diagnose it,
but not me.
in/dateposted-public/
I know electric blankets are old technology. I know they
functioned well
for decades with maybe a rheostat and perhaps a couple of
other
components. Why add unrepairable complexity?

Don't know. We use devices like the blue one in the
following picture.
<https://upload.wikimedia.org/wikipedia/commons/4/4b/
W%C3%A4rmflasche1.jpg>
and better isolating blankets. No electricity necessary. :-)

:-) But you imply that _I'm_ the one insufficiently modern?

Post by Wolfgang Strobl
A few lights in our house are switched by set of 2 x 3
inexpensive
wireless sockets including two remote controls, that I
bought eleven
years ago. I've still to replace the batteries. Two of the
sockets are
still spares, I have a replacement cell for the remote
controls stored
which might live even longer. Standard type, used in
garage openers and
burglar alarms, too. Selecting a channel and paring one of
the four
buttons of a remote control with one or more of the
sockets is as easy
as pie, using a line of dip switches inside those
devices. Quite
similar to pairing switches and derailleur on our bicyles.
While I avoid having essential functionality in my house
depend on
wireless connections, I enjoy having the option, for
certain use cases,
though.

Yuck.
I bought a new pedestal fan for our back patio last year.
I've found a fan to be the best defense against mosquitos.
The previous one still runs, but exposure to sunlight
destroyed its plastic finger protection screen.
Anyway, the new one comes with a remote control, roughly the
size of a snack cracker. Who needs a remote to adjust a fan?
I rejected ceiling fans with remotes when I was shopping,
too. It's something to lose, something whose battery will
die, and something whose electronics will go bad and be
unrepairable.
...

Post by Wolfgang Strobl
That one must have been standing around inside most of the
time, perhaps
for a reason.

My favorite bike is a young 39 years. It looks perfect, in
part because I had it (and my wife's matching one) stripped
and powder coated a couple years ago. Too many excellent
memories to let it go.

Not only the electronics infestation of consumer products.

I brought food to make girlfriend's birthday dinner last
evening and I cook in her kitchen regularly but sometimes
the modern kitchen stove is a real impediment.

[break for electronics rant: Her new kitchen stove, as her
furnace, both run from the large LP tank in the yard. Both
'improved' designs cannot run without electronic
start/valves etc so when the power is out there is no heat
whatsoever and power outages in rural USA are periodic.]

The new kitchen stove has electronic controls for the
burners and oven (oven controlled by a touch pad not, a
physical switch). The burner controls have 4 positions
only, viz., Off, Low, High, Start. That's really difficult
for some cooking projects. Resolved by moving the two pans
off and on the flame, which is Just One More Thing when
timing two dishes at once.

Only a designer who has never actually cooked would think of
that. Works fine for brewing coffee or boiling pasta but
limited for many projects.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Frank Krygowski

2025-01-12 19:24:16 UTC

[break for electronics rant: Her new kitchen stove, as her furnace, both
run from the large LP tank in the yard. Both 'improved' designs cannot
run without electronic start/valves etc so when the power is out there
is no heat whatsoever and power outages in rural USA are periodic.]

ISTM that more and more devices are built with a design philosophy
founded on "Everything will always be working." That limitation you
describe on the furnace would make me very nervous - but I suppose the
rest of the furnace doesn't work without electricity.

My backup is a wood fireplace. Without its blower grate, etc. it
wouldn't be as efficient, but at least the living room would stay warm.

--
- Frank Krygowski

zen cycle

2025-01-11 04:47:44 UTC

Post by Wolfgang Strobl
Am Fri, 10 Jan 2025 07:25:48 -0800 schrieb Jeff Liebermann

Post by Jeff Liebermann
On Fri, 10 Jan 2025 05:19:53 -0500, zen cycle

Post by Jeff Liebermann
On Sat, 4 Jan 2025 20:51:16 -0500, Frank Krygowski

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.
The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.
When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

I never could get used to the RPN data entry method

Humans tend to prefer whatever technology they learned first.

MY freshman year at Northeastern was the first year they didn't use
punchcards for the intro fortran class. We were 'treated' to the TA
giving a punchcard demonstration at one point. I uttered a prayer of
thanks to the Technology Gods.

zen cycle

2025-01-11 04:57:20 UTC

<BIG snip>
This makes me reflect on the criticism of electronics in bicycles. I'm
not talking about replacing muscle power by motor power, that's
replacing bicycles by something else. But what about measuring the
amount of power applied to the pedals, what about telling the cyclist
who balanced he splits the power between left and right, by
instrumenting the pedal or the bottom bracket? What about replacing
those awkward cables and complicated brifters with simple electric
switches and an encrypted wireless channel? Is that bad, because a
blacksmith can't repair it with his tools, like giving a horse a new
pair of horse shoes? What about LED lights, then? Shouldn't we get
back to incandescent bulbs, powered by bottle dynamos?
I think we should not and can not turn back the wheel, at least not like
this. I accept that there are reasons to keep bicycles simple, or to
keep at least some biycles simple enough to long lived and usable even
without much maintenance and without exotic stuff. But the question is,
what makes a component or material exotic? Is a specific bowden cable or
a gear hub or hub generator really less exotic and simpler to
replace/recreate than, say, a LED light or a wireless shifter? I doubt
it.
There is a point when mechanical parts become complicated enough to
create a vendor lock-in, when a second source isn't available. Just like
with electronic parts. Sometimes the relationship gets reversed, when an
over-engineered and complicated mechanical solution is replaced by a
simple construction that combines commercially available electronics
with simple mechanical parts.
In this respect, you have to take a close look at where a dependency
arises, instead of simply linking it to characteristics such as “new”,
“electronic” or “wireless”. We need open standards, either through
industry commitments, or by regulations.

+1
A well-written pro technology rant.
thank you.

Frank Krygowski

2025-01-10 16:59:26 UTC

Post by zen cycle
I never could get used to the RPN data entry method

For the sorts of computations Mechanical Engineers sometimes make, it's
much more efficient. I'm talking about evaluating complex formulas with
multiple layers of parentheses. Something like equation 10-28 at
https://engineeringlibrary.org/reference/shaft-analysis-air-force-stress-manual

For a while, I was one of the guys teaching the walk-in-the-door "Intro"
class to students entering our programs. Part of that was efficiently
using one's calculator. Guys with Algebraic entry calculators tended to
get lost in the layers of parentheses. The few guys with RPNs tended to
be much faster, with fewer mistakes.

But a person does have to get used to the RPN procedure - which is
really, just approaching the problem the way you'd do it by hand.

--
- Frank Krygowski

Frank Krygowski

2025-01-10 16:48:42 UTC

Post by Jeff Liebermann
On Sat, 4 Jan 2025 20:51:16 -0500, Frank Krygowski

No need to check. When that calculator got stolen, the guys running the
company bought me a replacement. By then, the 11C was no longer
marketed, so I ended up with an HP 32S II, one of the few RPN machines
still in their line, IIRC.
The 11C seemed bulletproof, but this 32S is a bit flaky. Its the
calculator I keep in my workshop drawer, so it's not used very often.
But it seems that at least a third of the time I want to use it, it
refuses to turn on. I've slipped a little note in its case with notes on
the recovery procedure.
When it flakes out, I'll usually just pull out my Android phone and run
the HP 48G emulator. My main complaint about that one is that it isn't
really programmable - or at least, it doesn't retain programs when the
app is killed.

You don't need to do that for me. I'll stick with the calculators I have.

--
- Frank Krygowski

Jeff Liebermann

2025-01-05 00:06:26 UTC

Post by Jeff Liebermann
In early college, I couldn't afford a real
scientific calculator (HP-35).
(...)
<http://www.vintagecalculators.com/html/texas_instruments_sr-10.html>
I eventually obtained an HP-35 just in time to have the administration
temporarily ban the use of calculators during exams.

Something is wrong with my dates. The HP-35 was introduced in Feb
1972. I graduated from college in June 1971. I attended a few months
of teacher prep classes in late 1971, but don't recall having or
needing an HP-35 calculator during that time. There is no possible
way I could have owned an HP-35 before it was offered for sale in Feb
1972.

It seems that I did something wrong, mangled my dates, faulty memory,
etc. That's not surprising for something that happened 54 years ago.
The problem is I don't know where I made the mistake. I still have
both the SR-10 and HP-35 calculators and boxes. I'll see if there are
some dates on the paperwork in the boxes. Meanwhile, please ignore my
comments related to the HP-35.

Sorry for the confusion.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

zen cycle

2025-01-05 10:49:38 UTC

Something is wrong with my dates. The HP-35 was introduced in Feb
1972. I graduated from college in June 1971. I attended a few months
of teacher prep classes in late 1971, but don't recall having or
needing an HP-35 calculator during that time. There is no possible
way I could have owned an HP-35 before it was offered for sale in Feb
1972.
It seems that I did something wrong, mangled my dates, faulty memory,
etc. That's not surprising for something that happened 54 years ago.
The problem is I don't know where I made the mistake. I still have
both the SR-10 and HP-35 calculators and boxes. I'll see if there are
some dates on the paperwork in the boxes. Meanwhile, please ignore my
comments related to the HP-35.
Sorry for the confusion.

I was actually thinking your college years would have predated the
HP-35, but wasn't sure and was too lazy to look it up.

I remember the day my father brought home a Bowmar Brain.

http://www.vintagecalculators.com/html/bowmar_calculators.html

I was a freshman in high school, would have been 1975.

Wolfgang Strobl

2025-01-04 20:59:45 UTC

Am Sat, 4 Jan 2025 13:02:24 -0500 schrieb Frank Krygowski

Post by Jeff Liebermann
On Thu, 2 Jan 2025 12:17:22 -0500, Frank Krygowski

Most probably it wasn't as large and as heavy as this one. :-)
<Loading Image...

--
Thank you for observing all safety precautions

zen cycle

2025-01-05 10:35:29 UTC

In my never humble opinion,

IMNHO....Nice...The Interwebs newest intialism.....

Jeff Liebermann

2025-01-05 21:39:49 UTC

On Sun, 5 Jan 2025 05:35:29 -0500, zen cycle

In my never humble opinion,

IMNHO....Nice...The Interwebs newest intialism.....

I think you mean initialism.
<https://www.merriam-webster.com/dictionary/initialism>
I've been using "in my never humble opinion" in its fully expanded
form for probably 50 years. I typically the phrase only once per
posting, so there's no need for acronymization.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

zen cycle

2025-01-06 09:57:32 UTC

Post by Jeff Liebermann
On Sun, 5 Jan 2025 05:35:29 -0500, zen cycle

In my never humble opinion,

IMNHO....Nice...The Interwebs newest intialism.....

I think you mean initialism.

Indeed I did. It was a typo.

Post by Jeff Liebermann
<https://www.merriam-webster.com/dictionary/initialism>
I've been using "in my never humble opinion" in its fully expanded
form for probably 50 years. I typically the phrase only once per
posting, so there's no need for acronymization.

I think you mean _an_ acronymization. :)

Jeff Liebermann

2025-01-06 21:19:32 UTC

On Mon, 6 Jan 2025 04:57:32 -0500, zen cycle

Post by Jeff Liebermann
On Sun, 5 Jan 2025 05:35:29 -0500, zen cycle

In my never humble opinion,

IMNHO....Nice...The Interwebs newest intialism.....

I think you mean initialism.

Indeed I did. It was a typo.

I left out a word. It should read "I typically use the phrase..."
Thanks for not noticing.

Post by zen cycle
I think you mean _an_ acronymization. :)

No. I consider acronymization as the process of converting a human
readable and easily understood phrase into a cryptic, difficult to
decode and sometimes clever acronym as "acronymization".
<https://en.wiktionary.org/wiki/acronymization>

Bike Culture Acronyms:
<https://www.bikeforums.net/general-cycling-discussion/400164-bike-culture-acronyms.html>

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

AMuzi

2025-01-06 13:40:50 UTC

Post by b***@www.zefox.net
But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.

I think that would be true only if the smooth pavement were
as smooth as a linoleum floor. Or a wooden track. IIRC, what
got Jan Heine started on investigations of rolling
resistance vs. tire width was coast-down tests on a Soapbox
Derby track. I suspect that was quite smooth. Soapbox cars
have hard tires and no suspension, AFAIK.

Post by b***@www.zefox.net
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire
and
suspenesion. In that limit, suspension would be faster if
used
with very hard tires on very smooth surfaces. In the
limit of
hard tires and no suspension, the dissipative element
becomes
the rider whose elastic properties are apt to be poor,
perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will
affect
dissipation depending on internal resonances of the bike/
rider
system. A real road likely corresponds to a 1/f spectrum,
but
a rumble strip will likely be something else. How much
difference
that makes isn't clear but it could be estimated using a
mechanical
analogy equivalent circuit of the kind used to model
loudspeakers.
A pair of series RLC circuits (one for the road-tire
interface
and a second for the suspension-rider interface) would be
a good
start. I'm not skilled enough to do the calculations, but
others
on this group likely are.

I _may_ have been able to do such calculations 50 years ago,
but I'm not sure. I certainly can't do them now.

Post by b***@www.zefox.net
The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid
mass but
rather a dissipative blob....8-)

I actually think physically modeling that dissipative blob
might be valuable for the tire industry. Using such a blob
to apply weight during a rolling drum test might give better
information than what those tests give now.

Post by AMuzi
Clever.
I take from that, you think the actual impact/height
change/velocity change etc from various irregular surfaces
can be quantified for any given random gravel (or road)
experience and used to compare efficiency for other
iterations.
I hadn't thought of that, but if that's true then the
rumble strip test isn't necessary for comparison. Which
assumes sensors have adequate sensitivity across whatever
range and that software for that data truly derives actual
impedimenta values.

There are ways of quantifying roughness, with varying
scales, varying tools. I'm most familiar with roughness
measurement of machined parts, with tools varying from
sample cards for "fingernail" test comparisons, to RMS
readers akin to phonograph needles or laser scattering devices.
https://en.wikipedia.org/wiki/Surface_roughness
ISTR reading about systems for evaluating pavement fairly
crudely, as in whether it should be repaved or not. I don't
know of a system actually used for measuring pavement
roughness at a scale affecting bike tire choice.

Tangential, but this was just sent to me and I found it
fascinating, Under 2 minutes:

https://www.youtube.com/shorts/TGuxwgUyu2A

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Zen Cycle

2025-01-03 15:41:05 UTC

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.

This is a great analysis and reveals a highly problematic aspect of the
"rumble strip" test. As Bob notes, it's essentially limiting the noise
input into the system to a somewhat narrow spectral component (though
the 1/f assumption for real-world is way to broad)

The idea of using the rumble strip test seems adequate at first, but is
prone to misleading results. Since the rumble strip sets up a regular
frequency component, there's a possibility that a resonance or
cancellation effect can occur which can dramatically skew the results.

In the world of environmental testing, physical vibration analysis is
typically broken up into three different stimuli - swept frequency,
noise*, and environmental specific (usually a combination of noise with
higher energy components around certain frequencies).

It's nearly impossible to simulate all the possible real-world
conditions, which is why the testing regimen includes a sweep - the
intent being to see any resonances. I've personally witnessed an
electronic assembly quite nearly disintegrate with the right frequency
and energy input. The task then was to redesign the piece such that the
resonance was damped.

It's easy to see how this can translate to the rumble strip test. Under
the right conditions, one might actually see a speed _increase_ as a
result of a sympathetic resonance.

Post by b***@www.zefox.net
A pair of series RLC circuits (one for the road-tire interface
and a second for the suspension-rider interface) would be a good
start. I'm not skilled enough to do the calculations, but others
on this group likely are. The hardest part is apt to be finding
an equivalent circuit for the rider, who isn't a rigid mass but
rather a dissipative blob....8-)

In the old days, we had to do reiterative tests on massive vibration
tables. These days, FEA software removes the vast amount of guesswork.
The last few times I've had to conduct these tests I only had to do one
test twice, and the problem turned out to be an assembly specification
error rather than inherent design.

Post by b***@www.zefox.net
Thanks for reading,
bob prohaska

"Real-world" would simulate a more stochastic environment with larger
"impact" events rather than a regular "sinusoidal" spectrum like a
rumble strip. Currently, for example, we use this for our truck-mounted
electronics:

https://cvgstrategy.com/wp-content/uploads/2019/08/MIL-STD-810H-Method-514.8-Vibration.pdf

Refer to page 514.8C-5 (Page 58 in the PDF).

Post by AMuzi
I hadn't thought of that, but if that's true then the rumble strip test
isn't necessary for comparison. Which assumes sensors have adequate
sensitivity across whatever range and that software for that data truly
derives actual impedimenta values.

Even low-cost accelerometers have incredible accuracy, sensitivity, and
repeatability across spectrum they're designed to operate these days. We
have two 3-axis units accurate to .01G that we paid like $25 each for -
coupled to a mid-range oscilloscope they give more than adequate results
for our "warm fuzzy" testing before we send of to a testing lab for 3rd
party analysis.

*"Noise" being a broad term meaning quasi-random frequency and amplitude
components within limits.

--
Add xx to reply

AMuzi

2025-01-03 16:17:59 UTC

Post by AMuzi
I don't have a coherent argument either way but a rumble
strip test introduces a repeatable experience so that
various data may be compared. Each rider on a dirt or
gravel path, and each ride experience by any given
rider, is
an unique set of impedimenta such that data cannot be as
readily compared.
I don't have a coherent argument either way but a rumble
strip test introduces a repeatable experience so that
various data may be compared. Each rider on a dirt or
gravel path, and each ride experience by any given
rider, is
an unique set of impedimenta such that data cannot be as
readily compared.

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire
and
suspenesion. In that limit, suspension would be faster if
used
with very hard tires on very smooth surfaces. In the
limit of
hard tires and no suspension, the dissipative element
becomes
the rider whose elastic properties are apt to be poor,
perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will
affect
dissipation depending on internal resonances of the bike/
rider
system. A real road likely corresponds to a 1/f spectrum,
but
a rumble strip will likely be something else. How much
difference
that makes isn't clear but it could be estimated using a
mechanical
analogy equivalent circuit of the kind used to model
loudspeakers.

This is a great analysis and reveals a highly problematic
aspect of the "rumble strip" test. As Bob notes, it's
essentially limiting the noise input into the system to a
somewhat narrow spectral component (though the 1/f
assumption for real-world is way to broad)
The idea of using the rumble strip test seems adequate at
first, but is prone to misleading results. Since the rumble
strip sets up a regular frequency component, there's a
possibility that a resonance or cancellation effect can
occur which can dramatically skew the results.
In the world of environmental testing, physical vibration
analysis is typically broken up into three different stimuli
- swept frequency, noise*, and environmental specific
(usually a combination of noise with higher energy
components around certain frequencies).
It's nearly impossible to simulate all the possible real-
world conditions, which is why the testing regimen includes
a sweep - the intent being to see any resonances. I've
personally witnessed an electronic assembly quite nearly
disintegrate with the right frequency and energy input. The
task then was to redesign the piece such that the resonance
was damped.
It's easy to see how this can translate to the rumble strip
test. Under the right conditions, one might actually see a
speed _increase_ as a result of a sympathetic resonance.

Post by b***@www.zefox.net
A pair of series RLC circuits (one for the road-tire
interface
and a second for the suspension-rider interface) would be
a good
start. I'm not skilled enough to do the calculations, but
others
on this group likely are. The hardest part is apt to be
finding
an equivalent circuit for the rider, who isn't a rigid
mass but
rather a dissipative blob....8-)

In the old days, we had to do reiterative tests on massive
vibration tables. These days, FEA software removes the vast
amount of guesswork. The last few times I've had to conduct
these tests I only had to do one test twice, and the problem
turned out to be an assembly specification error rather than
inherent design.

Post by b***@www.zefox.net
Thanks for reading,
bob prohaska

"Real-world" would simulate a more stochastic environment
with larger "impact" events rather than a regular
"sinusoidal" spectrum like a rumble strip. Currently, for
https://cvgstrategy.com/wp-content/uploads/2019/08/MIL-
STD-810H-Method-514.8-Vibration.pdf
Refer to page 514.8C-5 (Page 58 in the PDF).

Post by AMuzi
I hadn't thought of that, but if that's true then the
rumble strip test isn't necessary for comparison. Which
assumes sensors have adequate sensitivity across whatever
range and that software for that data truly derives actual
impedimenta values.

Even low-cost accelerometers have incredible accuracy,
sensitivity, and repeatability across spectrum they're
designed to operate these days. We have two 3-axis units
accurate to .01G that we paid like $25 each for - coupled to
a mid-range oscilloscope they give more than adequate
results for our "warm fuzzy" testing before we send of to a
testing lab for 3rd party analysis.
*"Noise" being a broad term meaning quasi-random frequency
and amplitude components within limits.

Thanks I knew nothing about this before our discussion.

--
Andrew Muzi
***@yellowjersey.org
Open every day since 1 April, 1971

Zen Cycle

2025-01-03 18:49:46 UTC

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/ rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.

This is a great analysis and reveals a highly problematic aspect of
the "rumble strip" test. As Bob notes, it's essentially limiting the
noise input into the system to a somewhat narrow spectral component
(though the 1/f assumption for real-world is way to broad)
The idea of using the rumble strip test seems adequate at first, but
is prone to misleading results. Since the rumble strip sets up a
regular frequency component, there's a possibility that a resonance or
cancellation effect can occur which can dramatically skew the results.
In the world of environmental testing, physical vibration analysis is
typically broken up into three different stimuli - swept frequency,
noise*, and environmental specific (usually a combination of noise
with higher energy components around certain frequencies).
It's nearly impossible to simulate all the possible real- world
conditions, which is why the testing regimen includes a sweep - the
intent being to see any resonances. I've personally witnessed an
electronic assembly quite nearly disintegrate with the right frequency
and energy input. The task then was to redesign the piece such that
the resonance was damped.
It's easy to see how this can translate to the rumble strip test.
Under the right conditions, one might actually see a speed _increase_
as a result of a sympathetic resonance.

In the old days, we had to do reiterative tests on massive vibration
tables. These days, FEA software removes the vast amount of guesswork.
The last few times I've had to conduct these tests I only had to do
one test twice, and the problem turned out to be an assembly
specification error rather than inherent design.

Post by b***@www.zefox.net
Thanks for reading,
bob prohaska

"Real-world" would simulate a more stochastic environment with larger
"impact" events rather than a regular "sinusoidal" spectrum like a
rumble strip. Currently, for example, we use this for our truck-
https://cvgstrategy.com/wp-content/uploads/2019/08/MIL- STD-810H-
Method-514.8-Vibration.pdf
Refer to page 514.8C-5 (Page 58 in the PDF).

Post by AMuzi
I hadn't thought of that, but if that's true then the rumble strip
test isn't necessary for comparison. Which assumes sensors have
adequate sensitivity across whatever range and that software for that
data truly derives actual impedimenta values.

Even low-cost accelerometers have incredible accuracy, sensitivity,
and repeatability across spectrum they're designed to operate these
days. We have two 3-axis units accurate to .01G that we paid like $25
each for - coupled to a mid-range oscilloscope they give more than
adequate results for our "warm fuzzy" testing before we send of to a
testing lab for 3rd party analysis.
*"Noise" being a broad term meaning quasi-random frequency and
amplitude components within limits.

Thanks I knew nothing about this before our discussion.

The lab we go to has a system similar to this:

--
Add xx to reply

Frank Krygowski

2025-01-03 16:50:21 UTC

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.

This is a great analysis and reveals a highly problematic aspect of the
"rumble strip" test. As Bob notes, it's essentially limiting the noise
input into the system to a somewhat narrow spectral component (though
the 1/f assumption for real-world is way to broad)
The idea of using the rumble strip test seems adequate at first, but is
prone to misleading results. Since the rumble strip sets up a regular
frequency component, there's a possibility that a resonance or
cancellation effect can occur which can dramatically skew the results.
In the world of environmental testing, physical vibration analysis is
typically broken up into three different stimuli - swept frequency,
noise*, and environmental specific (usually a combination of noise with
higher energy components around certain frequencies).
It's nearly impossible to simulate all the possible real-world
conditions, which is why the testing regimen includes a sweep - the
intent being to see any resonances.

Interesting. I suppose the rumble strip test could do a "sweep" by
riding repeatedly at a wide range of speeds.

--
- Frank Krygowski

Zen Cycle

2025-01-03 19:04:00 UTC

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.

This is a great analysis and reveals a highly problematic aspect of
the "rumble strip" test. As Bob notes, it's essentially limiting the
noise input into the system to a somewhat narrow spectral component
(though the 1/f assumption for real-world is way to broad)
The idea of using the rumble strip test seems adequate at first, but
is prone to misleading results. Since the rumble strip sets up a
regular frequency component, there's a possibility that a resonance or
cancellation effect can occur which can dramatically skew the results.
In the world of environmental testing, physical vibration analysis is
typically broken up into three different stimuli - swept frequency,
noise*, and environmental specific (usually a combination of noise
with higher energy components around certain frequencies).
It's nearly impossible to simulate all the possible real-world
conditions, which is why the testing regimen includes a sweep - the
intent being to see any resonances.

Interesting. I suppose the rumble strip test could do a "sweep" by
riding repeatedly at a wide range of speeds.

I was thinking we could mount a bike frame with a dent in the top tube
on an industrial vibration table and see what frequency profile is
require to pop the dent out....

But enough serious science, how about fun with resonance?!?!

https://www.youtube.com/shorts/AJuUIyc73dk

--
Add xx to reply

Frank Krygowski

2025-01-03 23:41:56 UTC

Post by Zen Cycle
But enough serious science, how about fun with resonance?!?!
https://www.youtube.com/shorts/AJuUIyc73dk

Yep. Chladni patterns. The salt settles into the vibrational nodes.

That technique has been used extensively to study violin acoustics, and
some maker use it to check their work in progress. Example:

At about 1:45 he shows his use of a reference to explain what patterns
he's trying to achieve. The carving of the top and back is laborious,
shaving the surface by hand so its constantly changing thicknesses
generate the right modes of vibration in response to various frequencies.

More of the process is at

with checking by Chladni patterns at about 13:00 or so. There's much
more available on this if you look around YouTube and other sources.

--
- Frank Krygowski

Radey Shouman

2025-01-03 21:16:49 UTC

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.

This is a great analysis and reveals a highly problematic aspect of
the "rumble strip" test. As Bob notes, it's essentially limiting the
noise input into the system to a somewhat narrow spectral component
(though the 1/f assumption for real-world is way to broad)
The idea of using the rumble strip test seems adequate at first, but
is prone to misleading results. Since the rumble strip sets up a
regular frequency component, there's a possibility that a resonance
or cancellation effect can occur which can dramatically skew the
results.
In the world of environmental testing, physical vibration analysis
is typically broken up into three different stimuli - swept
frequency, noise*, and environmental specific (usually a combination
of noise with higher energy components around certain frequencies).
It's nearly impossible to simulate all the possible real-world
conditions, which is why the testing regimen includes a sweep - the
intent being to see any resonances.

Interesting. I suppose the rumble strip test could do a "sweep" by
riding repeatedly at a wide range of speeds.

Or you could just ride one of these:

https://www.mentalfloss.com/article/73142/musical-roads-5-places-where-streets-sing
--

Frank Krygowski

2025-01-03 23:19:16 UTC

Post by Radey Shouman

Post by Frank Krygowski
Interesting. I suppose the rumble strip test could do a "sweep" by
riding repeatedly at a wide range of speeds.

https://www.mentalfloss.com/article/73142/musical-roads-5-places-where-streets-sing

I remember reading about that Honda one in a different bicycle forum. In
that forum, John Allen, who is a rather brilliant bicyclist and music
person, was able to figure out and explain what Honda had done wrong. It
comes down to a dimensioning mistake. He didn't go into quite as much
musical detail as this article, but he got it right.

https://davidsd.org/2008/12/honda-needs-a-tune-up/

The article goes into a fair amount of mathematical music theory.

--
- Frank Krygowski

b***@www.zefox.net

2025-01-03 19:23:10 UTC

But one can observe that in the case of smooth pavement,
suspension losses vanish, while hysteresis losses persist.
In the end a bike is an overdamped resonator excited by the
pavement and damped by hysteresis, separately in the tire and
suspenesion. In that limit, suspension would be faster if used
with very hard tires on very smooth surfaces. In the limit of
hard tires and no suspension, the dissipative element becomes
the rider whose elastic properties are apt to be poor, perhaps
accounting for the apparent slowness of solid tires.
Use of a rumble strip for testing is equivalent to selecting
a particular excitation spectrum. Choice of spectrum will affect
dissipation depending on internal resonances of the bike/rider
system. A real road likely corresponds to a 1/f spectrum, but
a rumble strip will likely be something else. How much difference
that makes isn't clear but it could be estimated using a mechanical
analogy equivalent circuit of the kind used to model loudspeakers.

One can put some bounds on the spatial frequencies of interest. Those
longer than the tire radius likely don't make it past the tire. Likewise,
those shorter than the contact patch don't either, though they might
still excite internal flexural losses in the tire. Neither of those
constraints is exactly true, but true enough for practical purposes.

Delta function inputs, like hitting a sharp edge, are physically
relevant (it happens) but not relevant to analysis of efficiency,
the first rule of efficiency being "don't crash". 8-)

Post by Zen Cycle
The idea of using the rumble strip test seems adequate at first, but is
prone to misleading results. Since the rumble strip sets up a regular
frequency component, there's a possibility that a resonance or
cancellation effect can occur which can dramatically skew the results.

In a lightly damped system, yes. in an overdamped system I'd put that
use case in the same category as hitting a curb. More trouble than it's
worth apart from avoiding it.

Post by Zen Cycle
In the world of environmental testing, physical vibration analysis is
typically broken up into three different stimuli - swept frequency,
noise*, and environmental specific (usually a combination of noise with
higher energy components around certain frequencies).
It's nearly impossible to simulate all the possible real-world
conditions, which is why the testing regimen includes a sweep - the
intent being to see any resonances. I've personally witnessed an
electronic assembly quite nearly disintegrate with the right frequency
and energy input. The task then was to redesign the piece such that the
resonance was damped.
It's easy to see how this can translate to the rumble strip test. Under
the right conditions, one might actually see a speed _increase_ as a
result of a sympathetic resonance.

I'm not sure of that. Energy injected from the strip must be reflected
back on the rebound to be recovered. Since there are losses at every
step of the excitation process I think the rolling resistance will
always be elevated at resonance, though some modes could have lower
losses than others. Either way, the rider won't like it.

Post by b***@www.zefox.net
Thanks for reading,
bob prohaska

"Real-world" would simulate a more stochastic environment with larger
"impact" events rather than a regular "sinusoidal" spectrum like a
rumble strip. Currently, for example, we use this for our truck-mounted
https://cvgstrategy.com/wp-content/uploads/2019/08/MIL-STD-810H-Method-514.8-Vibration.pdf
Refer to page 514.8C-5 (Page 58 in the PDF).

Post by AMuzi
I hadn't thought of that, but if that's true then the rumble strip test
isn't necessary for comparison. Which assumes sensors have adequate
sensitivity across whatever range and that software for that data truly
derives actual impedimenta values.

The notion of mounting accelerometers on axles, seatpost and rider is a
good one if somebody is motivated to do it. It might shed light on the
importance of frame stiffness as well.

Post by Zen Cycle
*"Noise" being a broad term meaning quasi-random frequency and amplitude
components within limits.

Thanks for reading!

bob prohaska

Jeff Liebermann

2025-01-04 04:27:04 UTC

This is close, but not quite what you're asking.

"Energy Harvesting from Bicycle Vibrations by Means of Tuned
Piezoelectric Generators"
<https://www.mdpi.com/2079-9292/9/9/1377>
<https://mdpi-res.com/d_attachment/electronics/electronics-09-01377/article_deploy/electronics-09-01377-v2.pdf?version=1598515211>

On PDF page 14, it proclaims:

"8. Prediction of Generated Power
The electrical power harvested by a piezo-harvester is very low (in
the order of a few mW), so highly-efficient power management units
(PMU) have to be used for energy conversion. The output voltage of the
piezo-harvester is a random signal with a main harmonic component at
the resonance vibration frequency of the cantilever. On the other
hand, electronic loads (such as a battery for energy storage and/or a
portable device which can be mounted on a bicycle) are typically fed
by DC voltage; therefore, interface electronic circuits between the
piezo-harvester and the load are made up by a rectifier (for AC to DC
voltage conversion), an electrolytic capacitor for voltage leveling
and energy storage, and DC-DC converter for impedance matching with
the electronic load resistance."

Page 17 has a table of generated power at various speeds.

Of course it's possible to optimize the bicycle design, material
(tire) selection, road surface profile, etc to produce the most power
output. Presumably, the generated electric power will be used to
power an electric and mechanical doping system. The problem is that
when you're starting with milliwatts, it's a long way to go before
sufficient power can be harvested to make a difference in a race or on
a ride.

--
Jeff Liebermann ***@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

Roger Merriman

2025-01-03 16:38:26 UTC

Post by Roger Merriman

Not that convinced to be honest, for a starters folks aren’t going to be
riding rumble strips but by mistake!
And if you’re going to be real world testing, testing on dirt roads with
all of the inconsistencies that brings is what gravel riders do. With the
dips as well as the bumps, plus ruts etc.
Rumble strip testing seems somewhat misleading ie it’s not that controlled
nor what riders do.
As ever claims that they influence pro athletes etc and started the wider
tire use, IMO it along with disks was adapted by consumers/commuters with
pro racers lagging behind with adoption and haven’t gone quite as wide, ie
stopped at 28 for the Pros where as 30/32 are fairly common among club
riders.

I’d say that’s a fairer test as it’s what riders do, and if the experiment
shows no difference, that’s fair enough.

I ride my MTB and Gravel bike on same trails, depending on trail conditions
and how technical the trail is, will depend on which bike is faster and my
times generally group fairly close.

Post by AMuzi
In short you make an interesting point but it's not
measurable for comparative purposes.

Roger Merriman

cyclintom

2025-01-03 16:12:46 UTC

Post by Frank Krygowski
Good article from Jan Heine on benefits of wider, softer tires for
https://www.renehersecycles.com/the-missing-link-suspension-losses/
At the time the rumble strip test was published, I expressed some
skepticism because its roughness is fundamentally different than the
random roughness of either a rough road or a gravel road. In particular,
the rumble strip is all "negative," cut into the smooth surface, while
rough or gravel roads have both "negative" holes plus "positive" patches
or rocks that protrude above the surface. One practical difference is
that when dealing with only "negative" roughness, higher speeds reduce
losses. The opposite is true with "positive" roughness.
But I suppose for demonstrating the fundamental effect, the consistency
of the rumbles is useful. And the measurements seem valid as long as the
test speed is also consistent.
BTW, Jobst Brandt is mentioned in the article. I recall that in
discussing rolling resistance here, he insisted that "rolling
resistance" should be defined _only_ as the losses generated by tire
rubber's hysteresis. I disagreed, because that implied that solid rubber
tires a la 1880, or near infinite tire pressure, or even metal rims with
no tire, would be best. Anyone who has ridden an antique solid tire
"safety" bike knows how slow those tires were.

Coming out of Niles Canyon, you have to ride at around 20 mph Because of traffic I was forced to cross a rumble strip with my 28 mm tires and came damned close to losing control but it did allow me to let 5 cars moving at 45 mph + get past before a constriction. While you're talking about taking the lane why don't you come here and try taking the lane? You would soon discover, if you're lucky, from a hospital bed that California deivers don't like your ideas.

Frank Krygowski

2025-01-03 16:59:15 UTC

Post by cyclintom
Coming out of Niles Canyon, you have to ride at around 20 mph Because of traffic I was forced to cross a rumble strip with my 28 mm tires and came damned close to losing control but it did allow me to let 5 cars moving at 45 mph + get past before a constriction. While you're talking about taking the lane why don't you come here and try taking the lane? You would soon discover, if you're lucky, from a hospital bed that California deivers don't like your ideas.

Ah. We haven't had a "Bicycling is really dangerous _HERE_!" post in
quite a while.

So you judged that nearly losing control in front of a 45 mph car was
safer than legally taking the lane? Yes, my choice would have been
different, and I've made that choice in <gasp!> California; but
admittedly not in your super-dangerous neighborhood. When I do that,
motorists wait until its safe to pass. Exceptions are vanishingly rare.

As I often ask, what do you do when riding in a ten foot lane with no
shoulder, when an 8.5 foot wide truck approaches from behind? Do you
jump off the bike and humbly bow?

--
- Frank Krygowski

Roger Merriman

2025-01-03 18:17:54 UTC

Post by cyclintom
Coming out of Niles Canyon, you have to ride at around 20 mph Because of
traffic I was forced to cross a rumble strip with my 28 mm tires and
came damned close to losing control but it did allow me to let 5 cars
moving at 45 mph + get past before a constriction. While you're talking
about taking the lane why don't you come here and try taking the lane?
You would soon discover, if you're lucky, from a hospital bed that
California deivers don't like your ideas.

Ah. We haven't had a "Bicycling is really dangerous _HERE_!" post in
quite a while.
So you judged that nearly losing control in front of a 45 mph car was
safer than legally taking the lane? Yes, my choice would have been
different, and I've made that choice in <gasp!> California; but
admittedly not in your super-dangerous neighborhood. When I do that,
motorists wait until its safe to pass. Exceptions are vanishingly rare.

I’d assume most folks would ie use the road than ride in the gutter on the
rumble strips! Though I can’t see much evidence of any bar a central line,
so as ever not sure how/why Tom would be riding in those.

Seems on a very brief search that some gutters have been used by some
cyclists as painted bike lanes, which isn’t a wildly good idea at best of
times! And are unhappy at the possibility of encountering rumble strips,
which seems likely to be a poor road all around!

Do have some painted gutters though Heathrow which i suspect the might
trick the unwary into thinking they are bike lanes, though it’s a fairly
car centric type of roads so probably somewhat self selecting, ie I’ve only
ever seen folks like myself ie brave folks on road bikes, though it’s a
very rarely go though on the commute MTB which the gutters are less of no
no as it’s plush tires are unfazed by drain covered, and one is traveling
quite a lot slower, though even so it’s not a terribly wise idea.

Roger Merriman

Post by Frank Krygowski
As I often ask, what do you do when riding in a ten foot lane with no
shoulder, when an 8.5 foot wide truck approaches from behind? Do you
jump off the bike and humbly bow?

cyclintom

2025-01-04 20:39:10 UTC

Post by cyclintom
Coming out of Niles Canyon, you have to ride at around 20 mph Because of
traffic I was forced to cross a rumble strip with my 28 mm tires and
came damned close to losing control but it did allow me to let 5 cars
moving at 45 mph + get past before a constriction. While you're talking
about taking the lane why don't you come here and try taking the lane?
You would soon discover, if you're lucky, from a hospital bed that
California deivers don't like your ideas.

Ah. We haven't had a "Bicycling is really dangerous _HERE_!" post in
quite a while.
So you judged that nearly losing control in front of a 45 mph car was
safer than legally taking the lane? Yes, my choice would have been
different, and I've made that choice in <gasp!> California; but
admittedly not in your super-dangerous neighborhood. When I do that,
motorists wait until its safe to pass. Exceptions are vanishingly rare.

I?d assume most folks would ie use the road than ride in the gutter on the
rumble strips! Though I can?t see much evidence of any bar a central line,
so as ever not sure how/why Tom would be riding in those.
Seems on a very brief search that some gutters have been used by some
cyclists as painted bike lanes, which isn?t a wildly good idea at best of
times! And are unhappy at the possibility of encountering rumble strips,
which seems likely to be a poor road all around!
Do have some painted gutters though Heathrow which i suspect the might
trick the unwary into thinking they are bike lanes, though it?s a fairly
car centric type of roads so probably somewhat self selecting, ie I?ve only
ever seen folks like myself ie brave folks on road bikes, though it?s a
very rarely go though on the commute MTB which the gutters are less of no
no as it?s plush tires are unfazed by drain covered, and one is traveling
quite a lot slower, though even so it?s not a terribly wise idea.
Roger Merriman

Post by Frank Krygowski
As I often ask, what do you do when riding in a ten foot lane with no
shoulder, when an 8.5 foot wide truck approaches from behind? Do you
jump off the bike and humbly bow?

It isn't a central divider I was talking about - it was a shoulder line.

Tom Kunich

2025-01-10 18:58:41 UTC

Post by Roger Merriman

Post by cyclintom
Coming out of Niles Canyon, you have to ride at around 20 mph Because
of traffic I was forced to cross a rumble strip with my 28 mm tires
and came damned close to losing control but it did allow me to let 5
cars moving at 45 mph + get past before a constriction. While you're
talking about taking the lane why don't you come here and try taking
the lane? You would soon discover, if you're lucky, from a hospital
bed that California deivers don't like your ideas.

Ah. We haven't had a "Bicycling is really dangerous _HERE_!" post in
quite a while.
So you judged that nearly losing control in front of a 45 mph car was
safer than legally taking the lane? Yes, my choice would have been
different, and I've made that choice in <gasp!> California; but
admittedly not in your super-dangerous neighborhood. When I do that,
motorists wait until its safe to pass. Exceptions are vanishingly rare.

I’d assume most folks would ie use the road than ride in the gutter on
the rumble strips! Though I can’t see much evidence of any bar a central
line, so as ever not sure how/why Tom would be riding in those.
Seems on a very brief search that some gutters have been used by some
cyclists as painted bike lanes, which isn’t a wildly good idea at best
of times! And are unhappy at the possibility of encountering rumble
strips, which seems likely to be a poor road all around!
Do have some painted gutters though Heathrow which i suspect the might
trick the unwary into thinking they are bike lanes, though it’s a fairly
car centric type of roads so probably somewhat self selecting, ie I’ve
only ever seen folks like myself ie brave folks on road bikes, though
it’s a very rarely go though on the commute MTB which the gutters are
less of no no as it’s plush tires are unfazed by drain covered, and one
is traveling quite a lot slower, though even so it’s not a terribly wise
idea.
Roger Merriman

Post by Frank Krygowski
As I often ask, what do you do when riding in a ten foot lane with no
shoulder, when an 8.5 foot wide truck approaches from behind? Do you
jump off the bike and humbly bow?

Roger, I don't know where you're coming from. The rumble strip here isn't
in the "gutter" but a 3" wide strip between the road and an open area you
can pull over into - it allowed all of the traffic to pass without me even
slowing down and the rumble strip disappeared allowing easy access to the
open road before the constriction under a railroad overpass.

This wouldn't be a subject save for Krygowski claiming that he ALWAYS took
the lane.

cyclintom

2025-01-04 20:15:34 UTC

Ah. We haven't had a "Bicycling is really dangerous _HERE_!" post in
quite a while.
So you judged that nearly losing control in front of a 45 mph car was
safer than legally taking the lane? Yes, my choice would have been
different, and I've made that choice in <gasp!> California; but
admittedly not in your super-dangerous neighborhood. When I do that,
motorists wait until its safe to pass. Exceptions are vanishingly rare.
As I often ask, what do you do when riding in a ten foot lane with no
shoulder, when an 8.5 foot wide truck approaches from behind? Do you
jump off the bike and humbly bow?

If you look at what I said (unlikely since you live in a world of your own making) you would see that I did not say that cycling was dangerous, but you have to ride in a manner that high speed traffic is expecting and your "take the lane" is not expected by either the drivers or the traffic engineers.

cyclintom

2025-01-09 20:20:47 UTC

Ah. We haven't had a "Bicycling is really dangerous _HERE_!" post in
quite a while.
So you judged that nearly losing control in front of a 45 mph car was
safer than legally taking the lane? Yes, my choice would have been
different, and I've made that choice in <gasp!> California; but
admittedly not in your super-dangerous neighborhood. When I do that,
motorists wait until its safe to pass. Exceptions are vanishingly rare.
As I often ask, what do you do when riding in a ten foot lane with no
shoulder, when an 8.5 foot wide truck approaches from behind? Do you
jump off the bike and humbly bow?

Frank, this is California and not Ohio (if there is any real diference in drivers). The roads which used to be some of the best in the nation are now some of the crapiest. It is really not a good idea to ride at 20 mph in front of a car approaching at 45-50 mph from behind that will ride up to within inches of your rear wheel. All it takes is one pothole or wobble and they make contact. Because of this you try 5to stay out of their way. I should also note that the speed limit in school zones when shool is in session is in many places (three blocks from me) 30 mph when children are entering or leaving school. And "traffic engineers" are trying to raise these speeds.

I simpy cannot believe that Ohio is that different from California. Whereever Democrats control they are bbusy feeding money from the public coffers to each other.

Frank Krygowski

2025-01-09 23:19:17 UTC

Post by cyclintom