Technique for Removing Cotter Pins?

[ChrisKH]

Beaten to it by lazyfatgit once I read the thread.

 

[jimboalee]

Hope you get the pins out clean.

Newer cotter pins are made of really soft mild steel and while being easier to file, the threads strip even easier.

Hammer them home with lick of grease.

 

[very-near]

Don't remove the nut. Just loosen it a couple of turns then hit it hard. If necessary loosen it again and hit. this prevents the end of the cotter pin mushrooming.

Good advice. I've used this method many a time. Cotter pins are just rubbish. They always leave play in the crank when you are pedalling if even slightly loose.

 

[JtB]

Ok own up .......

Who was it that suggested the C Clamp?

Well I'm striking that idea off my list.

Tomorrow there's going to be lots of banging, and if that doesn't work then drilling, and if that doesn't work then things are going to get very heated (with my blow torch) and if that doesn't work then a trip to the nearest skip.

 

[PpPete]

Heat first - then hammer.
Drill is your last resort, I've had to do it once. It's better than taking the thing to the skip, but that's about all you can say for it.

 

[JtB]

My hammer beat that rotter of a cotter

Job done and bottom bracket bearings replaced.
Thanks all for the help.

 

[michel29]

I had some hard time removing a resistant cotter pin : I put WD40 lubrificant + hammer without succes, so I tried this successful method :

View: https://www.youtube.com/watch?v=eyrumMdQVlQ

 

[gbb]

Don't remove the nut. Just loosen it a couple of turns then hit it hard. If necessary loosen it again and hit. this prevents the end of the cotter pin mushrooming.

That used to be my method, protects the thread (somewhat) from distortion, helps prevent the threaded section from bending as its hit with a hammer. If that fails, virtually everything else would have anyway, perhaps barring heat.
In the old days cotter pins were strong enough to re use, those days are long gone, I always used to put new ones in in my last throes of cotter pinned bikes.

 

[rrarider]

I've no idea what that crazy Frenchman was doing, as I couldn't see a bike anywhere in that clip. All I'd say is don't whack the pin without supporting the crank with a block of wood with a v shaped notch cut into it. This stops you damaging the bottom bracket bearings

 

[MichaelW2]

On no account hit the threaded end with a steel hammer. You will mash the thread and destroy the pin. New cottar pins are made from Chinese cheese.
Use a block to protect the thread of the pin a solid lump underneath to absorb the blow.

 

[weareHKR]

The French have never been good with engineering!