SCHLUMPF MOUNTAIN-DRIVE 2-speed internal chain-set gearbox

SCHLUMPF MOUNTAIN-DRIVE adds a very short extra gear, which enables you to ride even the steepest climbs, shrinking the gear ratio by a huge factor of 2.5x

anti-rotation clamp also works on Brompton folding bikes

170mm crank arms and 46T chainring as standard, other options available on request

installation and maintenance kit included

the super-flat planetary gearbox (only 10mm wide), blends in alongside the chainring in a seamless fashion

change gear  with a simple kick of the heel on the side buttons, while standing still or under heavy load

low maintenance

no cables, levers or derailleurs

high efficiency, high quality materials, ensure great longevity

symmetrical clutch allows full torque in both pedalling directions, making it compatible with coaster brakes and fixed-gear bikes without a rear brake

the optional EASY-SHIFT plates, available on request, cover the whole crank arms and allow for shifting by pushing on a larger area, best for clip-in pedals 

more on our ‘TECHNOLOGIES’ page