Old Peugeot Chainring Problem

[s***@gmail.com]

Friends,

I've got a 36-year-old Peugeot UO-8 that I've owned and used all these
years. I just replaced the front and rear derailleurs with vintage
parts I found on e-bay. But now I have a new problem. For no apparent
reason, the chain will fall off the big front chainring and land on the
small one. This is pretty disconcerting and dangerous. It appears to
happen at the same tooth in the chainring, but I'm not absolutely sure.
And yes, the chainring is a bit warped. And the crank does wobble a bit
in the bottom bracket.

The question is: what can I do about it? It seems like the big cahuna
repair is to replace the crankset, chainring and chain. My repair guy
says it'll be about $240 for modern parts (incl a cotterless crank). He
thinks that my vintage derailleurs will work with the new parts.

The alternative would be to replace the chainring and get a new chain.
Does that make sense? Where can I get those chainrings? What am I
looking for?

Thanks in advance for any help that anyone can offer.

Steve

[mark]

Post by s***@gmail.com
Friends,
I've got a 36-year-old Peugeot UO-8 that I've owned and used all these
years. I just replaced the front and rear derailleurs with vintage
parts I found on e-bay. But now I have a new problem. For no apparent
reason, the chain will fall off the big front chainring and land on the
small one. This is pretty disconcerting and dangerous. It appears to
happen at the same tooth in the chainring, but I'm not absolutely sure.
And yes, the chainring is a bit warped. And the crank does wobble a bit
in the bottom bracket.
The question is: what can I do about it? It seems like the big cahuna
repair is to replace the crankset, chainring and chain. My repair guy
says it'll be about $240 for modern parts (incl a cotterless crank). He
thinks that my vintage derailleurs will work with the new parts.
The alternative would be to replace the chainring and get a new chain.
Does that make sense? Where can I get those chainrings? What am I
looking for?
Thanks in advance for any help that anyone can offer.
Steve

How much does the crankset wobble in the bottom bracket? If it's wobbling
enough then that might be enough to make the chain fall off the big
chainring.

The UO-8 was an entry level 10 speed, I'm not sure I would spend $240 to
repair one. After 36 years I think you've gotten your money's worth, treat
yourself to a new bike.

[s***@gmail.com]

The wobble is pretty small. I'm dubious that this is the problem
because the chain falls off at the same spot in the chainring.

The bike has served me very well and I'm reluctant to let it die.

I think I need those chainrings. Any idea where to look?

[mark]

Post by s***@gmail.com
The wobble is pretty small. I'm dubious that this is the problem
because the chain falls off at the same spot in the chainring.
The bike has served me very well and I'm reluctant to let it die.
I think I need those chainrings. Any idea where to look?

Try here, and don't hesitate to e-mail Sheldon for advice:
http://sheldonbrown.com/harris/french.html.

HTH,

[41]

Post by s***@gmail.com
The wobble is pretty small. I'm dubious that this is the problem
because the chain falls off at the same spot in the chainring.
The bike has served me very well and I'm reluctant to let it die.
I think I need those chainrings. Any idea where to look?

You have a nice bicycle which gives you much enjoyment, there's no
reason to change it. They are also quite beautiful.

1. Cranks wobble in the bottom bracket? You need to adjust the cup.
Left side, undo the locknut, tighten the cup, retighten the locknut.
It's easiest with the right tools (your bike shop can help) but
possible without (hammer and screwdriver...).

2. The problem only started after you changed derailleurs? Is it the
same front derailleur, in the same position? Is it perhaps hitting the
chain under load? Steel cranks can be a little flexy. Does this only
occur under load? It's possible to straighten warped steel chainrings
with judicious use of an adjustable wrench- careful! It's also possible
to make the problem worse.

3. Can you reproduce the problem while spinning the cranks in a stand?

4. It will be tough to get new chainrings and not worth it. A new
chainset is very worth it and not such a great expense, depending on
what you get. An aluminum cotterless chainset will be MUCH easier to
service, weigh less and be stiffer than what you have now. For
something new, Campagnolo Veloce with AC-S or AC-H bottom bracket is a
bargain:
<http://www.lickbike.com/productpage.aspx?PART_NUM_SUB='0076-75'>
Will beat most of what you can get on eBay.
Get your bike shop to take off the old steel cottered cranks, they are
a pain to work with. Installing the new cranks and BB is easy. How old
is your chain? SRAM PC48 is inexpensive and all you need.

My recommendaion is to get the Veloce cranks and a new chain, and have
a great time riding a very nice bicycle which you love.

[Dave Mayer]

Post by 41
Get your bike shop to take off the old steel cottered cranks, they are
a pain to work with. Installing the new cranks and BB is easy. How old
is your chain? SRAM PC48 is inexpensive and all you need.
My recommendaion is to get the Veloce cranks and a new chain, and have
a great time riding a very nice bicycle which you love.

Generally good advice - but we are talking about a 36-year old Peugeot here.
The bottom bracket is French threaded, which means you are restricted to
20-year-old bottom brackets.

My advice (because I regularly ride and service a 34-year old Gitane):
first, replace your shop guy. How exactly is he going to find a modern
bottom bracket for a French-threaded BB shell? And: $240 for upgrades to a
UO-8? Those must be bike shop prices. I've seen these complete bikes whole
at yard sales for a tenth of this cost.

Find a Community bike Co-op, or an old shop that has a lot of second-hand
parts. Shops that have take-off cranksets and old-style square-taper bottom
bracket spindles. Plan to replace the bottom bracket spindle/bearings and
crankset only. Cottered cranksets are low-end junk; you should be able to
find a decent used mid-range cotterless alloy crankset (such as a Sugino GT)
for a $25 or so.

Pray that the BB cups are not pitted. If they are, then you are really
hooped. There are no cartridge bottom brackets (or any off the shelf parts)
for French-threaded BBs. Only hope: a really old and knowledgeable shop, or
pay big $ on Ebay.

With respect to the BB spindle, it may take some experimentation to find the
right length, so this is why you need a shop with a bucket of old BB parts.
Start with spindles around 118mm that start with a 3-code. One of these
should cost about $5.

[Jasper Janssen]

Post by Dave Mayer
Generally good advice - but we are talking about a 36-year old Peugeot here.
The bottom bracket is French threaded, which means you are restricted to
20-year-old bottom brackets.

Or Phil Wood.

Post by Dave Mayer
first, replace your shop guy. How exactly is he going to find a modern
bottom bracket for a French-threaded BB shell? And: $240 for upgrades to a

At Phil Wood.

Post by Dave Mayer
UO-8? Those must be bike shop prices. I've seen these complete bikes whole
at yard sales for a tenth of this cost.

Phil Wood pretty much explains the prices, too. 44 bucks for the cups and
100 for the matching cartridge BB doesn't leave that much for the crankset
out of that 240; 100 bucks is about right for a decent but not fancy
crankset.

Post by Dave Mayer
Pray that the BB cups are not pitted. If they are, then you are really
hooped. There are no cartridge bottom brackets (or any off the shelf parts)
for French-threaded BBs. Only hope: a really old and knowledgeable shop, or
pay big $ on Ebay.

You can match the $44 Phil Wood cups with a relatively cheap Shimano BB --
which was it, UN-72 or something? It should be googlable on this group.

Post by Dave Mayer
With respect to the BB spindle, it may take some experimentation to find the
right length, so this is why you need a shop with a bucket of old BB parts.
Start with spindles around 118mm that start with a 3-code. One of these
should cost about $5.

Mainly, you need the right length that's specced for the crankset. If
that's too short because of rubbing, even though PW rings leave you 2.5 mm
extra of outward adjustment, you can get a longer one.


Jasper

[41]

Post by Dave Mayer
we are talking about a 36-year old Peugeot here.
The bottom bracket is French threaded, which means you are restricted to
20-year-old bottom brackets.

ooops- ah fohgot. Anyrate, French thread parts are pretty common on
eBay and generally they don't move well (not sure about BBs
specifically). Didn't TA or Stronglight still make French thread BBs,
if only until recently? I do know for sure that Stronglight still makes
the A9 headset in French thread.

Try: <www.veloland.com> <www.velostore.com>~

[jtaylor]

Post by s***@gmail.com
Friends,
I've got a 36-year-old Peugeot UO-8 that I've owned and used all these
years. I just replaced the front and rear derailleurs with vintage
parts I found on e-bay. But now I have a new problem. For no apparent
reason, the chain will fall off the big front chainring and land on the
small one. This is pretty disconcerting and dangerous. It appears to
happen at the same tooth in the chainring, but I'm not absolutely sure.
And yes, the chainring is a bit warped. And the crank does wobble a bit
in the bottom bracket.
The question is: what can I do about it? It seems like the big cahuna
repair is to replace the crankset, chainring and chain. My repair guy
says it'll be about $240 for modern parts (incl a cotterless crank). He
thinks that my vintage derailleurs will work with the new parts.

Get a new repair guy.

If you get a good one, he'll have french-threaded cups in a drawer somewhere
in the darker places of the shop. If he doesn't, email me, I think I have
an old cottered bb from a UO8 somewhere in the darker places of my basement.
You may not need new cups at all - take them and the axle out and clean
them. If they are not pitted grease them and use them.

The chain falling off at one place may go away when you remove the bb
wobble. If not, you may need to adjust the front gear. If you got one of
those nasty plastic simplexes you will need to fiddle with three elements -
the height, the orientation relative to the chainring plane, and the travel.
Don't tighten the clamp of the plastic simplex too much - they will crack,
especially if old.

You will probably need a new chain; you may need a new freewheel; you are
unlikely to need a new chainring. Yours is steel. If it still wobbles
after fixing the bb, bend it. I use an adjustable spanner; make sure the
crank arms are true first, then work on the rings.

Max you should pay is something like this:

cups - $20
axle - $10
chain - $15
cotters - $1 (each)
freewheel - $20

[s***@gmail.com]

Gentlemen --

I can't get over your generosity! Thank you so much for offering your
help in such detail. I have to say that I'm a bit intimidated by the
choices and some of the terminology. I'm pretty handy and can do basic
maintenence (new cables, new derailleurs) but I'm not a bike mechanic.

I think you're right that I need a new mechanic. My guy is great, very
supportive and helpful, but he instantly admits that he doesn't know
much about these old bikes.

However -- I did some careful riding this AM and tried to isolate the
problem. And it looks like I've got a broken link in the chain. Not
enough to break the chain, but enough to allow it to flex and come off
the chain wheel. I'm not absolutely certain that this is the problem,
but every time the chain comes off, the point of departure is right
behind the bad link (2-6 links behind).

I've uploaded some pictures of the bike and the broken link. (I
identified the broken link with a bit of nail polish). Don't laugh,
please! There's a lot of rust but it works and I ride it nearly every
day -- from bike path by the beach to trips to the grocery store.

http://avidtips.home.comcast.net/misc/peugeot/

I assume that the first step now is to get a new chain and see if this
helps. Is there anything else anybody would suggest? On re-examination,
I think the play in the bottom bracket is pretty slight.

Once again, thank you all so much for your support and help!

Steve

[mark]

Post by s***@gmail.com
However -- I did some careful riding this AM and tried to isolate the
problem. And it looks like I've got a broken link in the chain. Not
enough to break the chain, but enough to allow it to flex and come off
the chain wheel. I'm not absolutely certain that this is the problem,
but every time the chain comes off, the point of departure is right
behind the bad link (2-6 links behind).
I've uploaded some pictures of the bike and the broken link. (I
identified the broken link with a bit of nail polish). Don't laugh,
please! There's a lot of rust but it works and I ride it nearly every
day -- from bike path by the beach to trips to the grocery store.
http://avidtips.home.comcast.net/misc/peugeot/
I assume that the first step now is to get a new chain and see if this
helps. Is there anything else anybody would suggest? On re-examination,
I think the play in the bottom bracket is pretty slight.
Once again, thank you all so much for your support and help!
Steve

Is that the original chain? That would certainly cause problems. I'm a
little surprised that your bike mechanic didn't spot the problem.

Yes, you need a new chain, and probably a new freewheel (rear sprocket
cluster) since the teeth are probably quite worn. The good news is that
chains and freewheels for old bikes like yours are still readily available,
and the cost a lot less than a new bottom bracket and crankset.

[s***@gmail.com]

Yup -- it's the original chain. 1969.

New chain and new freewheel -- but you don't have to replace the
chainring or crankset? Needless to say, those teeth are worn, too.

Steve

[mark]

Post by s***@gmail.com
Yup -- it's the original chain. 1969.
New chain and new freewheel -- but you don't have to replace the
chainring or crankset? Needless to say, those teeth are worn, too.
Steve

Chainrings generally last a lot longer than freewhel cogs for various
reasons, and steel chainrings like yours can last a really long time. Your
bike has seen a lot of use, though, so you might end up needing to replace
the chainrings and/or bottom bracket and/ or crankset. I would try to
scrounge up some used parts, though, because finding new French threaded
parts to fit your bike is really going to be tough. Check the link I sent
you for more background on fixing up old French bikes.

[Michael Press]

In article

Post by s***@gmail.com
Gentlemen --
I can't get over your generosity! Thank you so much for offering your
help in such detail. I have to say that I'm a bit intimidated by the
choices and some of the terminology. I'm pretty handy and can do basic
maintenence (new cables, new derailleurs) but I'm not a bike mechanic.
I think you're right that I need a new mechanic. My guy is great, very
supportive and helpful, but he instantly admits that he doesn't know
much about these old bikes.
However -- I did some careful riding this AM and tried to isolate the
problem. And it looks like I've got a broken link in the chain. Not
enough to break the chain, but enough to allow it to flex and come off
the chain wheel. I'm not absolutely certain that this is the problem,
but every time the chain comes off, the point of departure is right
behind the bad link (2-6 links behind).
I've uploaded some pictures of the bike and the broken link. (I
identified the broken link with a bit of nail polish). Don't laugh,
please! There's a lot of rust but it works and I ride it nearly every
day -- from bike path by the beach to trips to the grocery store.
http://avidtips.home.comcast.net/misc/peugeot/
I assume that the first step now is to get a new chain and see if this
helps. Is there anything else anybody would suggest? On re-examination,
I think the play in the bottom bracket is pretty slight.
Once again, thank you all so much for your support and help!

Yes, time for a new chain and freewheel. Your chain rings
are fine.

[s***@gmail.com]

Okay -- I'm getting a new chain and freewheel. I also found a new bike
shop that says they have experience with old Peugeots. We'll see.

Thank you all so much -- you've been immensely helpful!

Steve

[s***@gmail.com]

New chain went on last week. Freewheel wasn't necessary. The bike new
feels like it's brand new! Smooth, tight, positive. The new shifters
didn't make much of a difference -- until the chain was replaced.

I'm now dealing with Beverly Hills Bike Shop in LA. They know a great
deal about older French bikes and were extremely helpful.

Once again, thank you all for your help.

Steve

[Donald Gillies]

Crankset looks like stronglight or nervar cottered.

This means that a new bottom bracket will demand a new cotterless
crank. You are better off trying to find a cotterless spindle to put
into your old french cups, get a $10 sugino maxy on ebay, they show
up all the time.

I can see by looking at the teeth that they are still in fine shape.
Unfortunately, it would probably cost $50 to get the entire chainwheel
rechromed. meanwhile, use brass wool and/or aluminum foil to remove
the rust and then wax the crank, if you want to reuse the crank.

good luck.

- Don Gillies
San Diego, CA