Abstract: The invention relates to a gear-change device for derailleurs or gear-change hubs in which by enlargement of at least one of the provided detents in the circumferential direction and by arrangement of a spring which biases the change lever in the one direction an easy adjustability is provided by an adjusting screw. Furthermore the exchanging of detent discs for easy adaptation to different gear ratio numbers is easily possible. The assembly of the gear changer is easy to effect in as much as two component groups can be prefitted independently of one another. A shift-over device for one direction, as utilized advantageously especially in derailleurs, can easily be integrated.