Bicycle Mechanics - Crank Cotter Removal
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Is there a good trick to remove a crank cotter pin out of old cranks without buying a special tool or destroying the cotter pin? I try hammering it out lightly, but the cotter will not budge. The tool costs more than the bike, I'm just trying to lube the BB. I appreciate an advice.
Oh, GOD, cotter pin removal.
Once again, Sheldon Brown's site has the most complete info around for cotter pin removal.
Check out Sheldon's site and be sure to:
1) Use plenty of Liquid Wrench lubricant before you start.
2) Leave the nut on the cotter. Unscrew it to the end of the cotter bolt so that the nut acts to protect the cotter bolt.
3) Use a support under the crank arm. I use an old steel seat post and a brick, then lower the bike (held in the bike stand) down into position so that the crank arm rests on the seat post. The rounded end of the cotter sits inside the steel post.
4) Use and old pedal axle as an awl rather than whacking the cotter directly with the hammer.
5) Use a strong WHAM with the hammer rather than light taps. Use a heavy hammer. You really need to knock it out with a single blow.
6) Sometimes, you can grab the crank arms and pull them towards each other to ever so slightly move the cotters and allow for hammer-whack removal.
Good luck. Stuck cotters suck bad.
05-26-03, 09:49 AM
#3, Mike, I would not use a brick, use a block of wood. The brick can chip or shatter, which on a bike is not a huge deal except for maybe getting a piece in your eye. Watched a safety film in tech school where the guy had supported a dozer blade with cinder blocks and they failed while his foot was under it, quite graphic.
Even having a cotter press is no garrantee, it destroys them as well as a hammer.
If you do destroy one, go to the oldest shop in town, they will have some hidden away(I have at least a hundred)
Take the old one with you, they come in a couple of sizes and profiles.
05-27-03, 06:36 AM
Make the support material a hardwood. Pine or softwood will absorb your blows.
Dont mash the threaded end of the pin with a hammer. Again, a piece of hardwood may protect the thread as you hit it.
Thank you all very much, I'll give it a whack following your advice. I felt really uncomfortable doing it without experience.
Shortcut: Hacksaw your bottom bracket. if you've got cotter pins the BB is probably crap anyway :-)
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