Vintage bike help

[DebW]

What are Cottered cranks?

I think I know but don't want to sound dumb when I go in to the LBS to talk about the freewheel fixer upper.

It's a way of attaching the crank arms to the bottom bracket spindle with metal pins about 8-9 mm in diameter. One side of the spindle shaft is flattened to match the flat tapered part of the pin. You slide on the crank arms, put the pin through the hole in the arms so the flat side of the pin matches the spindle flat, pound them in lightly, and screw on a nut. Often they would get munged after lots of riding and then the crank arms would develop play. Or they would get stuck and be really hard to get out. And everytime you removed them you had to readjust the front derailleur because the crank ended up in a slightly different place. Sure glad they are a thing of the past. But if you've got an old Motobecane Mixte from around 1970, it probably has them.

Here's a page from Sheldon Brown:
http://sheldonbrown.com/cotters.html

[Trek420]

DebW "Sure glad they are a thing of the past. But if you've got an old Motobecane Mixte from around 1970, it probably has them."

yep, ah, so that's why my LBS has them sorta off to the side on the bike. Have to talk with them about semi-affordable replacement. But the Mixte is a keeper I think, she's gonna fit me and be the "urban assualt bike".

Planlover "It enrages me that you are having funding difficulties in atmospheric science. That is only one of the most critical fields right now, with global warming"

Oh, that's never OT here. Anytime the weather is too bad to ride I blame Dubya for not signing the Kyoto treaty. But one thing that heartens me is this saying

"Everytime I see an adult on a bicycle, I no longer despair for the human race." H. G. Wells

Makes a good footer dontcha think?

[DebW]

DebW "Sure glad they are a thing of the past. But if you've got an old Motobecane Mixte from around 1970, it probably has them."

yep, ah, so that's why my LBS has them sorta off to the side on the bike. Have to talk with them about semi-affordable replacement. But the Mixte is a keeper I think, she's gonna fit me and be the "urban assualt bike".

I didn't mean to imply that cotter pins are completely awful, just that modern cotterless cranks are much better. Cotter pins were used for decades and generally worked OK. You do need to remove them periodically to repack the bottom bracket. And you should have a spare set of pins because sometimes they get munged as you remove them. If you or your LBS can remove the current set of cotterpins and the crank and BB are otherwise in good shape, there is no pressing reasons to replace the whole setup. If you extract the cotter pins once a year to service your BB, they should never get stuck.

BTW, cranksets that take cotter pins are made of steel, not alloy. Steel is not as stiff and the chainrings can get out of round. You may also notice them flexing when you stand on the bike. Rotate the crank and look at the chainring wobble. Sometimes it's bad enough to cause the front derailleur to scrape. The good thing is that if the chainrings get out of round, you can bend them back with something like a large (18") screwdriver. It's kind of like truing a wheel with brute force. Gee, now I'm feeling nostalgic - never thought I'd miss steel cranksets. If you lived near me, Trek420, I'd be at your house tomorrow truing those chainrings.

[Trek420]

DebW "Gee, now I'm feeling nostalgic - never thought I'd miss steel cranksets. If you lived near me, Trek420, I'd be at your house tomorrow truing those chainrings."

well, you could always move

I can see it now "Dear family? Dear job? I have to move to CA, there's this 20 year old French bike, we met online....I know you'll say it can't last but she's the most beautiful shade of light green, I must true her chainrings"

Rai Sue, stay tuned, the Motobecane kinda got sidetracked while I got new wheels for the commuter. since that's the bike i use often the mixte-fixie went on the back burner.

[Trek420]

My LBS just called and the Mixte Fixie is ready. If the traffic and forced overtime Gods are with me I might pick it up tonight (if not he's off to Vegas for the Bike expo, and I'll see her later).

Pictures...... doesn't do the color justice

[DebW]

My LBS just called and the Mixte Fixie is ready. If the traffic and forced overtime Gods are with me I might pick it up tonight (if not he's off to Vegas for the Bike expo, and I'll see her later).

Pictures as soon as I get 'em.

Woo Hoo!! Pictures!! Pictures!!

I want details. Did it keep the steel cottered crankset?

[Trek420]

Woo Hoo!! Pictures!! Pictures!!

I want details. Did it keep the steel cottered crankset?

I don't know yet Are cottered cranksets a good thing?

[BleeckerSt_Girl]

Here's a little blurb on old Motobecanes:
http://velo-orange.blogspot.com/2007...tobecanes.html
and
http://velo-orange.blogspot.com/2007...-old-bike.html

[plantluvver]

Quote:

"Everytime I see an adult on a bicycle, I no longer despair for the human race." H. G. Wells

That made my day, maybe even my week.

I feel like I am in my proper little pond, here.

I don't feel like a misfit. A few weeks ago, I was on a women's cruise, and one woman was discussing here sails. It felt so good to here all the technical terms come out of a woman's mouth, and women doing shoptalk. With men, there was often a question of why they were offering to help me. They sometimes expected a reward. And dealing with husbands of jealous wives, I was regarded as a threat, because why was I going along on a caving trip, and spending the weekend with five guys. And all I wanted to do was get underground, not under the sheets!

I LOVE it when you gals talk dirty bikes to me!

Mary

[Rai Sue]

Hey Trek420,

what kind of components are you pulling off of your motobecane mixte for the fixte project? I am always in serious fear that something on mine will break and I'll have to scramble. Well, that I will be in the middle of nowhere and I'll have to track down a swiss bottom bracket, or something stupid like that...

Also, gals, i got an old bike with cottered cranks, and found it was not hard at all to switch them out (despite scepticism from the bike shop guy).

What I did was I brought in the old spindle (for the french thread bb) to a bike store that has used parts. I sized it up to a used square-taper spindle, for my replacement. then i got some used cranks of a _slightly_ more modern vintage to match, and no more steel cranks to weigh me down.