The control device is for controlling a transmission ratio between a traction means and a wheel set rotatable about a wheel axle and including at least two wheel blades alternatively wrapped around by the traction means. At least one of the wheel blades is composed of several independently adjustable wheel rim segments. The adjustment of the wheel rim segments in relation to a fixed plane (plane of alignment) in which the traction means wraps around the wheel set is effected by the control device in a direction substantially transverse to the plane of alignment. The control device includes at least one electrically actuatable control element, in particular a servomotor, provided that the at least one control element is arranged to rotate with the at least two wheel blades.

The control device is for controlling a transmission ratio between a traction means and a wheel set rotatable about a wheel axle and including at least two wheel blades alternatively wrapped around by the traction means. At least one of the wheel blades is composed of several independently adjustable wheel rim segments. The adjustment of the wheel rim segments in relation to a fixed plane (plane of alignment) in which the traction means wraps around the wheel set is effected by the control device in a direction substantially transverse to the plane of alignment. The control device includes at least one electrically actuatable control element, in particular a servomotor, provided that the at least one control element is arranged to rotate with the at least two wheel blades.

A bicycle front shifting system includes operable to transmit a wireless signal, a crank assembly with two crank arms and a pedal on each of the two crank arms. The crank assembly is rotatable about a rotation axis. A front shift unit is coupled to the crank assembly and is rotatable about the rotation axis. The front shift unit includes a chain ring component with a big chain ring and a small chain ring. The small chain ring has a small diameter and the big chain ring has a big diameter that is larger than the small diameter. A shift mechanism is coupled to and rotatable with the chain ring component about the rotation axis. The shift mechanism is configured to receive the wireless signal from the shifter and to shift a chain between the big chain ring and the small chain ring according to the wireless signal.

A method for shifting a segmented gear may include rotating a gear cluster including a first gear and a coaxial second gear using a power transfer mechanism (e.g., a belt or a chain). The power transfer mechanism defines a plane and is wrapped partially around the first gear. and wherein the first gear has a plurality of gear segments independently movable (e.g., pivotable or translatable) into and out of the plane. A plurality of radially transitionable sliders are rotated in tandem with the first gear, and each of the sliders is operatively coupled to a corresponding one of the gear segments of the first gear. In sequence, each segment of the first gear is moved out of the plane of the power transfer mechanism by urging the slider in a radial direction using a segment actuator, such that the power transfer mechanism wraps at least partially around the second gear.

A method for shifting a segmented gear may include rotating a gear cluster including a first gear and a coaxial second gear using a power transfer mechanism (e.g., a belt or a chain). The power transfer mechanism defines a plane and is wrapped partially around the first gear. and wherein the first gear has a plurality of gear segments independently movable (e.g., pivotable or translatable) into and out of the plane. A plurality of radially transitionable sliders are rotated in tandem with the first gear, and each of the sliders is operatively coupled to a corresponding one of the gear segments of the first gear. In sequence, each segment of the first gear is moved out of the plane of the power transfer mechanism by urging the slider in a radial direction using a segment actuator, such that the power transfer mechanism wraps at least partially around the second gear.

A gearbox may include a drive spindle and several interconnected gear clusters arranged in a housing. A first of the gear clusters is coaxially fastened to the spindle, and has an outboard gear and an inboard gear. The first gear cluster drives a belt or chain to operate one or more of the other gear clusters, and the inboard gear is physically divided into a plurality of segments. A shifting system for the gearbox includes an actuator configured to urge the segments of the inboard gear of the first gear cluster into and out of the plane of the belt or chain via a toggle and slider mechanism, such that a gear ratio of the gearbox is changeable without displacing the belt or chain out of the plane.

A gearbox may include a drive spindle and several interconnected gear clusters arranged in a housing. A first of the gear clusters is coaxially fastened to the spindle, and has an outboard gear and an inboard gear. The first gear cluster drives a belt or chain to operate one or more of the other gear clusters, and the inboard gear is physically divided into a plurality of segments. A shifting system for the gearbox includes an actuator configured to urge the segments of the inboard gear of the first gear cluster into and out of the plane of the belt or chain via a toggle and slider mechanism, such that a gear ratio of the gearbox is changeable without displacing the belt or chain out of the plane.

A bicycle crank assembly comprises a sprocket unit and a crank axle. The sprocket unit includes a sprocket having a rotational center axis. The sprocket includes a plurality of driving teeth. A total number of the plurality of driving teeth is equal to or larger than 38. The crank axle extends along the rotational center axis. The sprocket unit is movable relative to the crank axle in an axial direction of the rotational center axis within a movable range having an axial length equal to or smaller than 8 mm.

The invention discloses a gear shift arrangement, which includes a sprocket cassette being adapted to be slidably mounted on a hub which is adapted to move on a horizontal axis of a spindle, the sprocket cassette further being adapted to operatively engage with a chain so that, in operation, the chain remains in one vertical plane; and movement means adapted to move the sprocket cassette along the hub transversely relative to the chain.

The invention discloses a gear shift arrangement, which includes a sprocket cassette being adapted to be slidably mounted on a hub which is adapted to move on a horizontal axis of a spindle, the sprocket cassette further being adapted to operatively engage with a chain so that, in operation, the chain remains in one vertical plane; and movement means adapted to move the sprocket cassette along the hub transversely relative to the chain.