Function
With speed-drive eliminate those hard-shifting large chainwheels and get more speed or slower cranking speeds at the touch of a button - with your heel or ankle! No cables, no derailleurs.

speed-drive doubles the existing gears (blue bars). You get higher gears (red bars).
 
How to shift?
It's so easy: push with the heel of your shoe either on the right or on the left side of the axle on the push button to change from high to low gear! That's all!
 
The new easy-shift levers make shifting a real pleasure - even with clic-in-pedals or small shoes.