Brompton M3L + Schlumpf, Swiss, Mountain Drive Crank, for about a 17" Low, and the high about 80", in 6 speeds.

both are planetary gears , so the 3~4 double shift is quick and easy in spite of the MD shift being like a 50-20 double crank.


Feel a need for Lots of gears ? there is a Sturmey narrow , 28 spoke 5 speed IGH that can take the same cogs as the Brompton BWR. for 10.


and put a double or triple crank and one of the custom Front derailleur mounts to really complicate the drivetrain ..


1962, I put a triple cluster on an AW3. and a triple crank for 3 cubed or 27 speeds.. 3 levers for shifting the hub and the 2 derailleurs.