The Schlumpf High Speed Drive is great for small-wheeled bikes to get larger gear ratios without a huge physical chainring.
The Schlumpf High Speed Drive can also be combined with a Rohloff SPEEDHUB 500/14 for an extremely wide gear range. The Schlumpf High Speed Drive is a popular choice for recumbents and trikes, usually combined with an intenal gear hub in the rear.
Two gear ratios are available without the chain moving between gears, and there's no front derailleur, shifter, or cables to maintain or clutter up your bike. You simply shift with a quick heel movement against the push-button axle in the center of the crank arm.
The gearing systems use a clutch plate design that won't slip under power and requires very little maintenance.
+ 2.5 overdrive ratio
+ Small physical chainring and larger effective chainring size in overdrive mode
+ 27T sprocket/ trouser guard comes standard (67.5T equivalent gear in overdrive)
+ 30 & 34T splined chainrings available (75 & 85 equivalent gears in overdrive) + 130mm BCD spider available for standard chainrings
+ Best when combined with a gear hub or rear cassette offering at least 250% range
+ Offers 1315% gear range when combined with Rohloff SPEEDHUB 500/14