Originally Posted by JohnDThompson

Not easily. You'd have to source axle and cones ground for 1/4" balls to fit the 8mm axle.

While you could, as @SquidPuppet suggests above, file the dropouts to accept a 10mm axle, a better solution might be to file flats on the axle to fit the 8mm slot. That way you wouldn't be altering the NJS aspect of the frame.

N.B. while I'm not really familiar with the minutia of NJS certification requirements, I can say that the Shimano track dropouts I have here have a standard 10mm slot.



I can't think of a reason why NJS would want an 8mm rear axle. Even standard front axles are 9mm.