As a kid I was taught to leave the nut on the cotter but loosen it a couple of turns. Then gently tap the nut to drive the pin out a bit, loosen some more and repeat if necessary.
If the pin is mangled or worn, don’t despair, replacements are cheap and available online – just make sure you match the outside diameter.
Hephest on
TBH, this look like the cotter pin has been ‘replaced’ with a bolt and the threads mashed to stop it coming out. Personally I would use a dremel or angle grinder (carefully) to cut the threaded part of the bolt flush with the crank and then use a drift to hammer the bolt out.
BD420SM on
These fucking things are impossible to make work right. Worst way of mounting a crank arm ever.
6 Comments
You gotta get that pin out without bending it. It’s a cotter pin that has a taper to secure the crank. May be tough to remove.
You can install the nut back on to protect the threads and take a hammer and tap tap tap it.
PB Blaster, etc first may help.
What is your plan/end goal? Cotter pins often need to be hammered out, and can get deformed during install or removal.
If you are reinstalling this crank, you may need a replacement cotter pin. Those can be tricky to find in 2024
https://www.sheldonbrown.com/cotters.html
[https://www.youtube.com/watch?v=aH5dFf4MiIk](https://www.youtube.com/watch?v=aH5dFf4MiIk)
As a kid I was taught to leave the nut on the cotter but loosen it a couple of turns. Then gently tap the nut to drive the pin out a bit, loosen some more and repeat if necessary.
If the pin is mangled or worn, don’t despair, replacements are cheap and available online – just make sure you match the outside diameter.
TBH, this look like the cotter pin has been ‘replaced’ with a bolt and the threads mashed to stop it coming out. Personally I would use a dremel or angle grinder (carefully) to cut the threaded part of the bolt flush with the crank and then use a drift to hammer the bolt out.
These fucking things are impossible to make work right. Worst way of mounting a crank arm ever.