If a Schlumpf drive shifts from one into the other gear without activating a gear shift button, the reason often is an unequal pretension of the kickplates (easy-shift levers).

These levers are slightly preloaded to prevent them from "rattle" on the crank surface. The amount of preload is shown on the photo on the right.

Good News: From February 2012 we will deliver kickplates with a modified fixation: they are still clamped between pedal and crankarm but are equipped with a solenoid, which acts on a steel gear shift button. Therefore no need to preload the kickplates and no danger of unexpected shifting!

If you want to replace old kickplates, you can exchange the gear shift buttons and mount two steel buttons (black colour -> photo on the right) together with the new kickplates with a solenoid inside.