Abstract: An automated bicycle transmission (10) comprises an actuator (17) for movement into predetermined positions of a sprocket change mechanism member (18) moving to engage a chain (19) for transmission of motion opposite a predetermined sprocket among a plurality of coaxial sprockets of different diameter (20). The actuator is controlled by an electronic control device (11) to which is connected a plurality of sensors including a sensor (1) for detection of bicycle speed, a sensor (13) for longitudinal slope or inclination of the bicycle and optionally a sensor (15) of stress transmitted by the cyclist to the pedals. The electronic device (11) compares values detected by the sensors with ranges of preset values corresponding to the various sprockets and controls engagement of the chain with the sprocket having a range of values including said detected values. There can also be provided a sensor (14) of movement of the pedals enabling operation of the actuator (17) only if the cyclist is pedalling.

Abstract: The pre-timed distribution unit, in particular for internal combustion engines, is constituted by a first sprocket wheel, and a second sprocket wheel with a plurality of sprocket sets, a multiple-link chain taut between said sprocket wheels and defining a space inside which a guide shoe is housed, which is constituted by at least a plate-shaped structure provided with guides radiused by a first and a second mating, trueing circumferential edges. In an alternative form of practical embodiment, the unit comprises a guide shoe whose guides are associated with enlarged, laterally protruding portions.

Abstract: The flapping-preventing runner (10) constituting the subject-matter of the present invention is constituted by two half-runners (11) and (12), each comprising a couple of divergent guides (14) designed for supporting and guiding the two branches of a transmission chain (21). The two half-runners (11) and (12) are housed inside the dead space existing between the sprocket wheels (19) and (20) and the transmission chain (21) which connects them. In an alternative form of practical embodiment of the invention, the guides (14) are provided with flanges (28) which totally enclose the two transmission chain branches (21).

Abstract: A bicycle wheel brake consisting of a pair of opposed friction blocks carried by respective levers pivoted, either directly or through a support, to the bicycle frame, so as to be controllable against the action of spring members to lock the blocks against the wheel rim. Each lever is pivoted at one side of the wheel so as to move on a plane substantially parallel to the plane tangential to the wheel.

Abstract: The invention relates to a rocking idler for guiding driving members such as roller chains, belts and like members, comprising a hub adapted to be freely rockably mounted on the same axis of rotation of a driving mechanism, said hub having extending therefrom in a diverging manner a couple of guiding means adapted to receive the respective two laps, the taut lap and the slackening lap of the chain and like driving means which is a part of the driving assembly.

Abstract: A motor unit for bicycles, characterized by the fact that it comprises a central axle for fitting to the fork of a bicycle, on which axle is rotatably supported a substantially cylindrical body adapted to form the hub of a wheel, there being fitted within said body and to the central axle the stator of a discoid rotor electric motor connected to the body by a kinematic transmission.