Abstract: A transmission chainformed of alternating outer chain links (2) and inner chain links (3), connected by pins (4);the outer chain links (2) and the inner chain links (3) being formed of outer plates (21) and inner plates (31);each outer plate (21) and inner plate (31) having two widened ends (23,33) each provided with a hole (25, 35) to accommodate the pin (4) and connected by a connection part (24,34) characterized in thatthe connecting parts (24,34) of the plates (21,31) comprise apertures (26,36) and the pins (4) are hollow.

Abstract: The tensioner includes a body (12) defining a blind cylindrical cavity (14) and a piston (20) slidably mounted in the cavity (14) and adapted to bias a pressure shoe (24) into contact with the endless connection element (26) so as to put the latter under tension. The inner end (18) of the cavity defines an orifice (28) for connection to a source of liquid under pressure and closable by a resilient blade (36) constituting a check valve.

Abstract: This device, of the type comprising a fixed part including a support element (1) adapted to be fixed on one part of the frame or the handle bar of the bicycle and a moveable part (2) including an operating hand-lever (3) which can rotate relative to the support element, a control mechanism (9) of which a first part (11) co-operates with the fixed part of the device and of which a second part (10) co-operates with the moveable part of the latter and a cable for actuation of the derailleur-gear, is characterized in that the cable for acutation of the derailleur-gear is connected to an actuation plug (4), rotated by the operating hand-lever (3) and on which are provided the control mechanism (9) and the means (16) for attaching the moveable part of the device to the fixed part of the latter.

Abstract: The device permits the control of a derailleur by means of a lever (9) with the use of indexation means which ensure a precise positioning of the lever in the various positions corresponding to the various gear ratios. It also permits the adjustment of the indexation pitch, so as to adapt it to freewheels having a different spacings or pitches between different sprocket pinions. For this purpose, positioning elements (19) may be shifted by a pitch selection element (21) so that the pitch between the various positions of the lever is modified.