Schlumpf has been making high-quality bicycle transmission products for more than 15 years. The Swiss company's latest Speed-Drive system will be available in summer 2008. The speed-drive is a planetary gearing system which replaces large hard-to-shift chainwheels, offering more speed or slower cranking speeds at the touch of a button - activated with the rider's heel or ankle.
There are no cables or derailleurs. The new speed-drive offers two gear ratios: direct drive 1:1 and overdrive 1:1.65. It can be combined with any internal rear hub or derailleur system, and is also ideal for single speed bikes.
The system uses easily exchangeable chainrings with 27, 30, 34, 36, 38t., which equal 45, 50, 56, 59, 63t. in high gear mode. The gear housing is corrosion resistant, completely encased in a lightweight aluminum housing and protected against dust and spray.