Originally Posted by
Space_doodle
Thanks everybody, for the version codes and suggestion to look at the right crank arm (duh). Mystery solved. Thanks.
So, did you find that the model # is different between your cranks?
The different models of the crank varies in the length of the spindle and has a
small effect on the chainline & thread width (Q factor). This allows options, depending on the frame specification and chainring(s).
The selection is based on the rear dropout spacings, configuration of the chainstay or other factors.