We are keeping this page on the site for reference only.
Switzerland's Schlumpf Innovations makes a nifty two-speed planetary gear system that fits into the bottom bracket of your bicycle. It allows the effect of a double chainwheel derailer system without derailing the chain.
Gear shifting is accomplished without hand controls or cables. There is a button on each side of the crank set designed to be operated by the rider's foot. Push on one side for the lower gear, push on the other side for the higher gear.
There are two basic models:
For example, if you use a 50 tooth chainring,
For example, if you use a 45 tooth chainring,
For example, if you use a 28 tooth chainring,
Optional Easy-shift lever
|Articles by Sheldon Brown and others|
Copyright © 2005, 2008 Harris Cyclery