samal

I'm converting an old motobecane into a singlespeed for my wife. It looks as though the cranks are held onto the bb by a cotter-type pin (nut and bolt). I have removed teh pin, but nothing else seems to want to budge. Do I have to force it? or am I doing something wrong?

Thankks for the help

operator

Use a the force

Aeroplane

If the cotter pin is completely out, I recommend whacking the side of the crank as if you want it to rotate around in the pedaling motion, and holding the other one. The spindle and the crank interface are both fairly round, and the only thing that should keep it from rotating like this under normal conditions is the cotter. So, since it's out, whacking it like this should loosen up the crank from all the corrosion that is probably holding it there now.

samal

I am having trouble removing the cotter pin. I can remove the bolt holding the pin in, but the pin is still in the crank. Do I just need to whack it, or is there a specific, yet gentle, way to go about it?

rustang

hammers fix everything.
duct tape fixes everything that the hammer fixed.

Sammyboy

Whack it. Whack it HARD. Don't tap it, it's fairly soft, and you'll round it off and make it harder to remove. Take a big hammer, and think how much power would be needed to drive it out with one blow. Then hit it twice that hard.

This is paraphrasing Sheldon's advice on the subject, and it's worked very well for me.

Aeroplane

Before you whack away at the pin: position the crank so it is horizontal with the threaded part of the pin up. Then take a section of pipe, and use that to support the crank under the other end of the cotter pin. Hopefully, at least one tire of the bike should be off the ground, have somebody else hold the bike steady if possible. Then whack away. The pipe is for giving you something solid to pound against, instead of having the force of the hammer go through the BB, frame, wheels, and tires to the ground.

Once that is set up, try to do it in one shot like Sammyboy says.

kemmer

I was afraid this was going to be another drug thread.

samal

thanks

-=(8)=-

I would keep the nut on the end of the pin too....just back it off 2 or 3 threads.
This way you wont damage the first couple threads or mushroom the pin.
When the pin is loose, then pull the nut all the way off and tap it through.

ericoseveins

man, i hate cotters.

i've found that a punch of some kind really helps. haven't tried using an old pedal spindle but i could see that working well if you don't have a punch. one thing's for sure, if it starts bending, STOP. you'll just mash it. take it to the shop or hardware store and they can cut the bent end off so that you're directing force in the right axis again.

ericoseveins

oh, and in the event that it's really bent and mashed and can't be cut, your final option is to try riding around on it. eventually the crank arm should come off, and hopefully you won't come off with it.

Snordalisk

Park cotter pin press!