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scozim

I was cleaning up the components for my Gitane build tonight and was feeling pretty good because everything was looking quite nice. As I went to put the nut on one of the cotter pins I was dismayed to find I had "ruined" the top of the pin when hammering it out of the crank and the nut won't thread on.

I guess I need to get other cotter pins for the Nervar crank but how are they measured - lengthwise, diameter. I'm assuming these are French thread but if I replace them that won't matter.

Scott

verktyg

Scott,

Buy a bunch of them when you find some. They're cheap and getting hard to find. Replace them as a matched set.

Standard French cotters are 9mm x 40mm or 43mm long with a 7mm x 1mm threaded end.

Old Peugeots used some 9mm x 37mm cotters with a taper the length of the pin and a 6mm x 1mm threaded end. The newer ones were close to French standard.

Brit, ISO and Japanese cotters are 9.5mm (3/8") by 41mm to 43mm with 6.7mm x 26 TPI, 1/4"-26 TPI (or 6mm x 1mm Japanese).

Italian cotters are 8.5mm x 41.5mm or 9mm x 43mm with a 7mm x 26 TPI threads and a short steep taper.

Chances are the cotters are standard French. Make sure that the new cotters look like the old ones - same length and taper.

They should fit in the crank arm with enough threads sticking out to start the nut 3-4 turns. The back end should also stick out of the crank arm.

http://www.sheldonbrown.com/cotters.html
http://www.sheldonbrown.com/tooltips/cotters.html

You may have to file the angles on the cotters to get them to fit properly.

Loose Screws Bicycle Small Parts has 9mm cotters for $1.00 a piece.

http://tinyurl.com/2g76g6j

Also Bike Tools Etc. for $1.95 each (they say that their cotters are 9mm x 31mm long but I think that they are measuring them wrong!).

http://tinyurl.com/29ckdgw

scozim

Thanks Chas. I've dealt with Loose Screws quite a bit and have sent them an email about their cotter pins.

Kirk

You can save yourself a lot of grief (and ruined parts) if you buy one of these:

It's expensive, but once you use it you'll agree that it's worth it.

Gtane

Kirk,

That's a clever device. There must be huge pressure exerted through this tool to release the pin and, on that point, am surprised at the coarseness of the thread. Looks very impressive yet simple. I like it.

Has this tool been able to remove every cotter pin that you have tried it on?

Thanks for the info.

Tim

scozim

My cotters are 39.4mm long (I'm assuming they would be marketed as 40 mm or 39 mm) and the Loose Screws ones are 42 mm with a 30 mm shank and 12 mm of threading. Will that cause a huge difference other than more threads showing understanding of course that some filing may be needed.

Kirk

Gtane

Thanks Kirk, I'll take a look.

Tim