Fixing an old French bicycle

[Sonorous Epithet]

More out of frugality than enthusiasm I bought an old French bike on Craigslist -- a 1985 Peugeot P6. I've been keen to fix it up but I seem to be making a real hash of it. Sheldon Brown's site has been very helpful with research but when it came down to actually do the repairs I seem to be doing terrible. I posted about this in my journal but I am looking for some more direct advice.

Biggest problem is that the left pedal goes bockety, by which I mean it feels like it's bent. The bike came with the original crank arm and (I think) the original pedals.

The original crank arm is a cottered crank, 170mm, with an odd 9mm cotter (vs a 9.5mm English style cotters) and (I think) standard 20TPI pedal threading.

The original pedals are touring style, with (I think) the standard 20TPI threading and left-handed threading.

After it went bockety, the pedal fell off the next day mid-ride. I cleaned the grease off and the pedal looked ok -- still true, threads intact, but half the threads were stripped on the crank arm. I went to my LBS and ended up getting a 6.5" crank with 9.5mm cotters and (I think) the standard 20TPI pedal threading -- not a 100% match, but it should have gotten the job done.

Got the cotter greased and hammered in ok, and greased the pedal and tightened it using a 6" crescent wrench and the normal mechanical advantage levering the opposite crank arm. Everything seemed ok, but 5 minutes into my ride, I hit a big bump and the same thing happened -- bockets. I haven't taken it apart for a post-mortem yet, nor have I ridden it since the test ride. I expect to see the same thread stripping.

Now I'm not sure what the problem is. I expect the pedal threads on the crank arm to be ruined again. I know the LBS has one more I can replace it with but I'm worried it will be more money wasted if I don't troubleshoot this correctly.

Any ideas as to what could be causing it? Could simply replacing the pedals at the same time as the crank arm work?

[Russ]

wrong pedals, yo

French threading is M14x1.25, vs. the new standard 9/16-20. Only .01" off on the diameter and .001" off on the thread pitch so you can't tell by looking at it, but it most definitely won't work right (as you know).

If you're ok with making the bike not-100%-French, I would suggest getting a new French-threaded square taper BB and new standard cranks & pedals to go with it so you aren't messing around with the wrong size cotter and weird pedals. There's very likely something wrong with the old BB anyway, and a new one should be like $30. Make sure you match taper on the cranks, there are 2 different standards there too

also be careful if you mess with the BB, they are right threaded on BOTH sides

[FunkyStickman]

Agreed, if you want to keep it all French, there are ways to do it, but it would be easier and cheaper to convert it to a standard English crank and pedals, with a French-specific sealed bottom bracket.

[Sonorous Epithet]

Thanks, gents. I will start to price that out. I've been torn between trying to learn to do it myself for the badassity and frugality of it, and throwing a bucket of money at professional mechanics to get it road ready ASAP.

I would suggest getting a new French-threaded square taper BB and new standard cranks & pedals

a French-specific sealed bottom bracket

I don't know much about bottom brackets, and I'm a little confused about your comments. If I'm converting to English sizes, what parts are French-specific? Could you perhaps link me to a specific BB that I can use as a basis of comparison for when I start to shop?

And do you think I can change out a BB by myself, being a mere beginner at bicycle repair, or should I have my LBS do it? (I am keen to learn, but my toolkit and knowledge base is pretty basic.)

[Russ]

Interfaces between parts are French (or English, ISO, JIS, etc...) standard. So where the bottom bracket meets the frame, both parts have to be French, because the frame is French and you can't change that. You can buy a BB such as this one that has French threads for attaching to the frame and a common JIS square taper (in place of the cotter) for attaching to the cranks. from there out, you would have standard cranks, and standard pedals.

To install the above BB, you would need this tool. You will probably need additional tools to remove the old BB, see this article. I wouldn't buy a tool for something I'm about to get rid of, so I would have the shop remove the old BB (which may be more of a job than you'd want to do yourself anyway, if it's rusted in or something), and install the new one yourself. They're quite easy: screw in one side, then screw in the other.

[Sonorous Epithet]

Thanks for the wonderful explanation! You have taken me from despondent to optimistic in the span of like 4 paragraphs. 

[FunkyStickman]

I've been building bikes for decades, sounds like Russ and others have some experience, too. Feel free to ask more questions, working on bikes isn't that bad once you learn the basics. It will save you tons of money in the long run.

I would love to find an old Peugot... I used to have one in college, but it was too small for me. Great bikes.

[Sonorous Epithet]

Took it into my LBS. (There's 3 shops around me, and I think this particular shop is my favorite. They are very beardy.) I knew they had a spare left crank if that's all it needed.

After looking at it and riding it around, they said there was play in the bottom bracket and, like you guys, suggested getting a whole new bottom bracket and crankset. Parts and labor was in the $150 range assuming it is a French threaded BB (Bracket was about 50, I think, and crankset was about 70). I hemmed and hawed and woe-is-me'd for a while then told them to go ahead and do it. I am ambivalent about paying for the labor for the whole thing -- it sounded reasonably priced and I wanted an expert's eye on it, but it's a lost opportunity to learn how to do it myself.

This bike is turning out not to be not quite a steal:

Bike $150
Bottom Bracket & Crank $150
Tires and tubes $50
Brake shoes $10
Accessories (rack, fenders, bell) $90

Total: $450

This is still a sight better than the new bikes I have been ogling, like the $900 Trek Crossrip or the $1500 Surly Long Haul Trucker. And this bike has some real style to it. Every time I look at it it feels rare and special and it makes me smile, and this is knowing it's 30 years old, full of obsolete technology, and was a relatively cheap mass-market bike even when it was new.

[FunkyStickman]

Yeah... it's hard to spend money on  a bike when you're used to cheap stuff. However... it will last you another 30 years. Well worth the investment.

[dilinger]

Another way to look at it is resale value, as well.  $360* for a bike that you can probably sell for $200+ after a few years of use.  I do this all of the time; $300-$400 for an el-cheapo steel frame fixed gear bike off of a website (bikesdirect has tons of good deals), use it for 2-5 years, tune it up, sell it for close to the original price on craigslist.

 * I'm not counting the $90 for bell, fenders, rack.  That's stuff you can pull off and use on your next bike, if you decide to switch later on.

[Sonorous Epithet]

Another way to look at it is resale value, as well.  $360* for a bike that you can probably sell for $200+ after a few years of use.  I do this all of the time; $300-$400 for an el-cheapo steel frame fixed gear bike off of a website (bikesdirect has tons of good deals), use it for 2-5 years, tune it up, sell it for close to the original price on craigslist.

 * I'm not counting the $90 for bell, fenders, rack.  That's stuff you can pull off and use on your next bike, if you decide to switch later on.

That is a fair point.

By the way, turns out that the bike uses a standard bottom bracket -- I guess by the mid-80s Peugeot had gone more mainstream with their part sizing. So that saved me the $30-40 premium on a French-threaded BB.

Bike should be ready for pickup tonight-ish.

[FunkyStickman]

Another way to look at it is resale value, as well.  $360* for a bike that you can probably sell for $200+ after a few years of use.  I do this all of the time; $300-$400 for an el-cheapo steel frame fixed gear bike off of a website (bikesdirect has tons of good deals), use it for 2-5 years, tune it up, sell it for close to the original price on craigslist.

 * I'm not counting the $90 for bell, fenders, rack.  That's stuff you can pull off and use on your next bike, if you decide to switch later on.

That is a fair point.

By the way, turns out that the bike uses a standard bottom bracket -- I guess by the mid-80s Peugeot had gone more mainstream with their part sizing. So that saved me the $30-40 premium on a French-threaded BB.

Bike should be ready for pickup tonight-ish.

Pictures, or it didn't happen!

[Sonorous Epithet]

Pictures, or it didn't happen!

I will, I will!

Have to get the white fenders on that match the white handlebar tape (and were 10 bucks cheaper than the black) before I show off pictures of my new commuter ;)