A drive train comprises a sprocket arrangement and a force-transmission coefficient. The sprocket arrangement includes a plurality of rear sprockets and a plurality of gear ratios respectively corresponding to the plurality of rear sprockets. The plurality of gear ratios includes a largest gear ratio and a smallest gear ratio. The sprocket arrangement includes at least one individual sprocket-space provided between two adjacent rear sprockets among the plurality of rear sprockets. The force-transmission coefficient is obtained by dividing a total gear range quotient by a total number of the at least one individual sprocket-space. The force-transmission coefficient is equal to or larger than 0.97 and is equal to or smaller than 1.36. The total gear range quotient is obtained by dividing the largest gear ratio by the smallest gear ratio.

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 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 guide element for bicycle drive means includes a main bearing pin for fixing a swing arm bearing. Further, a spacer sleeve is provided which is arranged on the main bearing pin for reducing a distance between a drive ring and a bicycle frame element.

A guide element for bicycle drive means includes a main bearing pin for fixing a swing arm bearing. Further, a spacer sleeve is provided which is arranged on the main bearing pin for reducing a distance between a drive ring and a bicycle frame element.

A derailleur comprises a base member, a chain guide, and a linkage structure. The linkage structure includes a first link pivotally coupled to the base member about a first link pivot axis. The chain guide includes a first chain guide pivotally coupled to the first link about a first guide pivot axis spaced apart from the first link pivot axis. The first chain guide includes a first guide body and a first guide protrusion. The first guide protrusion protrudes from the first guide body and is pivotally coupled to the first link about the first guide pivot axis. The first guide protrusion is spaced apart from the first link in an axial direction with respect to the first guide pivot axis to define an intermediate space between the first guide protrusion and the first link in the axial direction. The intermediate space is free of a spring.

A derailleur comprises a base member, a chain guide, and a linkage structure. The linkage structure includes a first link pivotally coupled to the base member about a first link pivot axis. The chain guide includes a first chain guide pivotally coupled to the first link about a first guide pivot axis spaced apart from the first link pivot axis. The first chain guide includes a first guide body and a first guide protrusion. The first guide protrusion protrudes from the first guide body and is pivotally coupled to the first link about the first guide pivot axis. The first guide protrusion is spaced apart from the first link in an axial direction with respect to the first guide pivot axis to define an intermediate space between the first guide protrusion and the first link in the axial direction. The intermediate space is free of a spring.

A bicycle front derailleur is provided that can be easily coupled to a bicycle frame. The bicycle front derailleur includes a base member, a chain guide and a link mechanism. The base member is configured to be coupled to a bottom bracket hanger of the bicycle frame. The chain guide is configured to guide a chain. The link mechanism connects the chain guide to the base member to move the chain guide between a retracted position and an extended position. The base member includes a recess configured to accommodate a part of the chain guide in a state where the chain guide is located at the retracted position.