To elaborate a little on what Phil and Chuck wrote; The offset between spindle bore and cotter bore varies somewhat from manufacturer to manufacturer and sometimes even from unit to unit of the same crank. The best cotters I sell have to be filed to fit most bikes, but will work on those with a larger offset.
With practice you can file them pretty flat but they are soft enough that it isn't a big deal if they aren't perfect.
At 5/13/2010 05:27 AM -0400, David Bean wrote:
>I have never understood why filing crank cotters is so widely recommended.
>Two new crank cotters (of the same mfr and type, of course) must have the
>same bevel. Using a file on that bevel seems likely to render it less flat
>than it started out; therefore more likely to come loose in service. What
>am I missing here?
>
>David Bean
>Arlington, MA USA
>beandk at are-see-enn dot com
Mark Stonich;
BikeSmith Design & Fabrication
5349 Elliot Ave S. Minneapolis, Minnesota 55417 USA
Ph. (612) 824-2372 http://bikesmithdesign.com
http://mnhpva.org