Originally Posted by
Andrew R Stewart
The absolute best cotter removal tool I have ever used is a pneumatic chisel with a punch bit in it. The combination of the vibration and the impact force loosened every pin with no pin deformation that I have use it on. And this experience was back in the late 1970s when pinned cranks were far more common then today. I have used the Var Constricteur press (which sucks), the two versions of the Park press (the cast and the folded and welded ones, which work fairly well), the Var brass hammer, many different punches and hammers (punch held in vice grip, thank you). And the pneumatic tool beats them all by far. Andy.
Thanks for this tip. I have an air chisel *** but had never thought to use it for this purpose. How badly, if at all, does it screw up the old cotter?
To the OP - my preferred method is with a bench vise and socket after overnight does of penetrant. I may or may not apply heat depending on my patience level at the moment. Downside to the method is that it's burdensome. I have had some luck with hammers, C-clamps and other homemade presses, but I can say that they have lead to damage (bike or tool) and frustration.
An aside: There is no bike-related job that I enjoy more than filing cotters to fit.