Abstract: A three-speed motorcycle transmission (1), to be used aboard a motorcycle as transmission means for 5 transmitting the motion generated by an engine to a driving wheel, having performances similar to those of a continuously variable transmission but, at the same time, a high efficiency and an easy automatic operation, comprises: a crankshaft (2), which receives the motion by 0 an engine, having a first pulley (9) mounted thereon; a primary shaft (4), having a second pulley (12) and a first set of three gears (21, 22, 23) mounted thereon; a transmission belt (11) connecting said first and said second pulley (9, 12); a secondary shaft (4), connected 5 to a driving wheel, comprising a second set of three gears (31, 32, 33), engaged in pairs with respective gears (21, 22, 23) of the first set of three gears for the transmission of the first, second and third speed; a clutch (10) acting selectively on at least two pairs of 0 gears assigned to the transmission of the second and third speeds; and two free wheels (15

Abstract: A continuously variable transmission system for a motorcycle includes a first drive sheave (12) operated by a transmission half-shaft (14) and a second driven sheave, connected by a V-belt. The drive sheave (12) has a first half-sheave (16) and a second half-sheave (18) substantially conical, sliding axially aligned, joined in rotation. The first half sheave (16) is fitted internally with a speed regulator composed of centrifugal masses (20) which move to cause the axial shift in the direction of extension of the transmission half-shaft (14), of the first half-sheave (16) relative to the corresponding second half-sheave (18). A device (10) for regulating the gear change curve is provided with an electromechanical actuator to cause selective intervention of a determined group of centrifugal masses (20) to vary, for the same number of revs of the engine, the centrifugal force needed to achieve the axial shift of the first half-sheave (16).

Abstract: A continuously variable transmission system for a motorcycle includes a first drive sheave (12) operated by a transmission half-shaft (14) and a second driven sheave, connected by a V-belt. The drive sheave (12) has a first half-sheave (16) and a second half-sheave (18) substantially conical, sliding axially aligned, joined in rotation. The first half sheave (16) is fitted internally with a speed regulator composed of centrifugal masses (20) which move to cause the axial shift in the direction of extension of the transmission half-shaft (14), of the first half-sheave (16) relative to the corresponding second half-sheave (18). A device (10) for regulating the gear change curve is provided with an electromechanical actuator to cause selective intervention of a determined group of centrifugal masses (20) to vary, for the same number of revs of the engine, the centrifugal force needed to achieve the axial shift of the first half-sheave (16).