A sprocket guard comprising a sprocket having sprocket radial spokes, and having teeth on an outer perimeter, the teeth disposed in a plane CL1, each sprocket radial spoke communicating with a first cylindrical surface, a circular member having circular member radial spokes, and each circular member radial spoke communicating with a second cylindrical surface, a collar having an outer cylindrical surface, a fastener engaging the collar, the first cylindrical surface and the second cylindrical surface engaging the outer cylindrical surface, all coplanar in a plane CL2, and plane CL1 is offset from plane CL2.

A seal for a bicycle drivetrain is configured to shield and protect part of the bicycle drivetrain from contamination by materials commonly found in the cycling environment, namely dirt, oil, water and other debris found on cycling surfaces. The seal is configured to shield the bicycle drivetrain from grit that may foul lockring interfaces, leading to seized threads, and cause difficulty removing the lock ring when it comes time to service the motor or replace the chainring.

A seal for a bicycle drivetrain is configured to shield and protect part of the bicycle drivetrain from contamination by materials commonly found in the cycling environment, namely dirt, oil, water and other debris found on cycling surfaces. The seal is configured to shield the bicycle drivetrain from grit that may foul lockring interfaces, leading to seized threads, and cause difficulty removing the lock ring when it comes time to service the motor or replace the chainring.

A V-belt type continuously variable transmission of an air-cooled type mounted on a vehicle. The V-belt type continuously variable transmission includes an intake port for taking air into the V-belt type continuously variable transmission, and an exhaust port for exhausting air from the V-belt type continuously variable transmission. The V-belt type continuously variable transmission further includes at least one of an electric intake fan connected to the intake port directly or via an intake duct, and an electric exhaust fan connected to the exhaust port directly or via an exhaust duct.

A pulley assembly including a drive pulley, a driven pulley, a flexible belt configured to connect the drive pulley to the driven pulley, an idler including a bearing and an idler pulley, the idler pulley engaged with the belt, the idler rotating about a first longitudinal axis, and an axial trap within the pulley assembly configured to restrict longitudinal movement of the idler along the first longitudinal axis.

A device for retaining a bicycle chain on a sprocket includes a base plate defining a plurality of fastener openings centered on an origin. A center of each of the plurality of fastener openings is disposed at a first radial distance from the origin. The origin defines an axis extending substantially orthogonally from a plane defined by two lines extending from the origin and at least two centers of the centers of the plurality of fastener openings. A first guard is secured to the base plate and includes a first guard retaining surface including a first curved surface defined by a second radial distance from the axis that is greater than the first radial distance and a first guard guiding surface having a first end adjacent the first guard retaining surface and a second end distal from the first end. The first end is disposed at the second radial distance from the axis. The second end is disposed at a third radial distance from the axis. The third radial distance is greater than the second radial distance. A second guard is secured to the base plate and includes a second guard retaining surface including a second curved surface defined by the second radial distance from the axis. A second guard guiding surface has a first end adjacent the second guard retaining surface and a second end distal from the first end. The first end is disposed at the second radial distance from the axis. The second end is disposed at a fourth radial distance from the axis. The fourth radial distance is greater than the second radial distance.

A device for retaining a bicycle chain on a sprocket includes a base plate defining a plurality of fastener openings centered on an origin. A center of each of the plurality of fastener openings is disposed at a first radial distance from the origin. The origin defines an axis extending substantially orthogonally from a plane defined by two lines extending from the origin and at least two centers of the centers of the plurality of fastener openings. A first guard is secured to the base plate and includes a first guard retaining surface including a first curved surface defined by a second radial distance from the axis that is greater than the first radial distance and a first guard guiding surface having a first end adjacent the first guard retaining surface and a second end distal from the first end. The first end is disposed at the second radial distance from the axis. The second end is disposed at a third radial distance from the axis. The third radial distance is greater than the second radial distance. A second guard is secured to the base plate and includes a second guard retaining surface including a second curved surface defined by the second radial distance from the axis. A second guard guiding surface has a first end adjacent the second guard retaining surface and a second end distal from the first end. The first end is disposed at the second radial distance from the axis. The second end is disposed at a fourth radial distance from the axis. The fourth radial distance is greater than the second radial distance.

Various techniques are provided to maintain drive belts at substantially constant tension over a wide range of conditions. In one embodiment, a system includes a housing, a bracket secured to the housing, first and second pulleys, and a belt engaged in tension with the first and second pulleys. The first and second pulleys are suspended from the housing through the bracket to reduce effects of thermal expansion of the housing on the belt tension. Other systems and related methods are also provided.

A cover for the sprocket (5) of a bicycle or electric bicycle consists of a cover plate (9) which is arranged between the chain wheel (5) and the equilateral crank (2) and fastened without screws on the inside of the crank.

A cover for the sprocket (5) of a bicycle or electric bicycle consists of a cover plate (9) which is arranged between the chain wheel (5) and the equilateral crank (2) and fastened without screws on the inside of the crank.