Originally Posted by
fietsbob
FWIW,
Mk3 sram 3x2 hubs are 3 speed spline Mk4 sturmey BWR hubs are shimano spline
on My Older Mk 2 bike rear end 15t is as large as fits , before the frame tube interference hits it.
I have a 15t cog from the Sram hybrid hub on my sturmey AW3.
Thanks for the warning. I have an SRAM 3 speed.
So it seems I need to get a custom made cog, but the one I am interested in changing is the smaller one, so might be hard to go smaller than what I have, which is a 13. Maybe a larger chainring combined with a larger large cog to compensate?