Abstract: The invention relates to a multispeed gearshift mechanism for bicycles. The gearshift mechanism contains a shaft (1), which can be mounted, fixed against relative rotation, on a bicycle frame, an actuator (7), rotatably seated on the shaft (1), a shell (12), rotatably seated on the shaft (1), and a gearshift mechanism, which is provided with a first and a second planetary gear (15, 16) and is arranged in the shell (12) for making available several gear ratios between the actuator (7) and the shell (12). The planetary gears (15, 16) have at least respectively two sun wheels (19, 20, or respectively 22, 23), which are coaxial in relation to the shaft (1) and which can be selectively connected by means of a shifting device with the shaft (1).

Abstract: The invention relates to a multispeed gearshift mechanism for bicycles.

Abstract: A roller chain for bicycles comprises a plurality of outer links each having a pair of outer plates each having two pin holes, two pins extending through the pin holes and connecting the outer plates of each of the outer links with one another, a plurality of inner links arranged alternately with the outer links and each having a pair of inner plates each provided with a bearing collar defining an inner hole and carrying a roller. The inner holes have a cross-section which is elongated in a longitudinal direction. At least one of the pin holes in the outer plates and the inner holes in the bearing collars are offset so that a roller pitch of the inner and outer links in a stretched state of the chain is adjusted substantially to the same value.

Abstract: The invention relates to a roller chain for chain drives, which has a plurality of inner and outer links alternating in tandem. The inner links have at least two inner plates having pairs of pin holes and having pin bearings disposed between the pin holes. The outer links contain each at least two outer plates which are joined together by at least two pins fastened in them. For the articulation of the outer links with two adjacent inner links each, the one pin of each outer link reaches through one of the pairs of pinholes and the associated pin bearing of one of the adjacent inner links, and the other pin of each outer link reaches through one of the pairs of pin holes and the associated pin bearing of the other of the adjacent inner links. The pin bearings are encompassed by rollers disposed for loose rotation between the inner plates.