Abstract: The derailleur comprises a finger member which bears on a cam surface. The finger member is carried by an arm of a parallelogram structure. The cam surface is provided on the support of the derailleur. Preferably, the cam achieves a tri-dimensional guiding of the finger member which carries a rotary roller.
Abstract: (a) Cycle provided with a speedometer.(b) Cycle characterized in that it comprises a clamp provided with an opening for its fixing on the axle of the wheel hub.