http://dualratiosprockets.com/
MAN! I would pay the money in a heartbeat if it fit my 511! I would just kill to go from 15/38t sprockets to 15/49.....
Good God I would be a happy camper
Requires a cush drive and horizontal drop outs....so far.
So marchesini wheels with a rear cush drive compatible, and then machine the dropout axle bracket and an axle.
MAN! I would pay the money in a heartbeat if it fit my 511! I would just kill to go from 15/38t sprockets to 15/49.....
Good God I would be a happy camper

Requires a cush drive and horizontal drop outs....so far.
So marchesini wheels with a rear cush drive compatible, and then machine the dropout axle bracket and an axle.