A belt drive system comprising a belt having a plurality of longitudinally spaced belt teeth, the belt further comprising a longitudinal groove extending in the endless direction of the belt through the belt teeth, a sprocket comprising a plurality of sprocket teeth on an outer circumference of the sprocket, each of the sprocket teeth extending parallel to the rotation axis, and each sprocket tooth configured to be received between adjacent belt teeth, and a first planar fin extending from at least one side of a sprocket tooth, the first planar fin configured to cooperatively engage the longitudinal groove, the first planar fin extending in a direction normal to a sprocket axis of rotation, the first planar fin having a width no greater than 20% of a sprocket groove width (W).

A scooter includes a scooter body with substantially triangular front and rear body portions. The substantially triangular front body portion has a front side and a first connecting side. The front side and the first connecting side of the front body portion form a first acute angle. The substantially triangular rear body portion has a rear side and a second connecting side. The rear side and the second connecting side of the rear body portion form a second acute angle. The first and the second connecting sides are connected so as to linearly slide with respect to one another such that when the scooter body is in an extended state the front side is in a greater distance from the rear side than a distance when the scooter body is in a compact state.

A scooter includes a scooter body with substantially triangular front and rear body portions. The substantially triangular front body portion has a front side and a first connecting side. The front side and the first connecting side of the front body portion form a first acute angle. The substantially triangular rear body portion has a rear side and a second connecting side. The rear side and the second connecting side of the rear body portion form a second acute angle. The first and the second connecting sides are connected so as to linearly slide with respect to one another such that when the scooter body is in an extended state the front side is in a greater distance from the rear side than a distance when the scooter body is in a compact state.

An electric assist bicycle and a drive system therefor includes a controller that includes control modes in which different assist ratios are calculated as control modes of the electric motor, and that stores a mode change condition that determines a change of the control mode. The controller performs the mode change when a pedal is located between an angular position that follows by 45 degrees a lowermost position of a locus of the pedal and an angular position that precedes by 45 degrees the lowermost position. Accordingly, the mode change is performed when the pedaling force exerted by a rider is relatively low such that the rider does not feel uncomfortable due to a rapid change of the load applied to the rider.

A bicycle chain comprises a first inner link plate and a second inner link plate. The first inner link plate comprises a first inner-link end portion, a second inner-link end portion, and a first inner-link intermediate portion. The second inner link plate comprises a third inner-link end portion, a fourth inner-link end portion, and a second inner-link intermediate portion. A first inner-link end edge has a first chamfer extending about the first inner-link center axis such that a part of the first chamfer is disposed in a first circumferential area defined from a first inner-link longitudinal centerline to a first reference line when viewed in an axial direction of the first inner-link center axis. The first circumferential area is smaller than 14 degrees.

A bicycle chain comprises a first inner link plate and a second inner link plate. The first inner link plate comprises a first inner-link end portion, a second inner-link end portion, and a first inner-link intermediate portion. The second inner link plate comprises a third inner-link end portion, a fourth inner-link end portion, and a second inner-link intermediate portion. A first inner-link end edge has a first chamfer extending about the first inner-link center axis such that a part of the first chamfer is disposed in a first circumferential area defined from a first inner-link longitudinal centerline to a first reference line when viewed in an axial direction of the first inner-link center axis. The first circumferential area is smaller than 14 degrees.

The apparatus comprises a rotary to variable linear converter which functions to steer a pivotable rotatable directional wheel of a vehicle. The converter comprises a driven rotatable cylinder and a rotatable pivotable friction wheel pressed against the surface of the cylinder so that they rotate together. The friction wheel is slidably mounted on guide rods extending parallel to the cylinder surface so that the friction wheel can advance helically along the cylinder if angled relative to the cylinder axis. The friction wheel generates a lateral force which is used to apply torque to the directional wheel to turn it. The orientation of the friction wheel is varied and controlled by a digit-operated control lever operated by a rider of the vehicle.

A balanced motorcycle powertrain is described. Embodiments of the balanced motorcycle powertrain include components mounted to a frame of a motorcycle such that the powertrain can be evenly balanced about a centerline of the frame. The balanced motorcycle powertrain can include, but is not limited to, a motor, a transmission, a pair of clutches, a clutch shaft, a crank shaft, a pair of superchargers, a pair of chains, a pair of rear sprockets, and a rear wheel. Each of the components can be oriented such that the powertrain is substantially balanced about the centerline of the frame.

A balanced motorcycle powertrain is described. Embodiments of the balanced motorcycle powertrain include components mounted to a frame of a motorcycle such that the powertrain can be evenly balanced about a centerline of the frame. The balanced motorcycle powertrain can include, but is not limited to, a motor, a transmission, a pair of clutches, a clutch shaft, a crank shaft, a pair of superchargers, a pair of chains, a pair of rear sprockets, and a rear wheel. Each of the components can be oriented such that the powertrain is substantially balanced about the centerline of the frame.

The present invention relates to a bicycle driving device having increased torque, the device moving, to the front thereof, the center of a rotational track in a state in which an overall pedaling track (distance) does not increase, thereby removing the top dead center and enabling force to be strongly transmitted to a crankshaft during pedaling. According to the present invention, a rotational track of a pedal is moved to the front thereof such that when the pedal is in a forward position, the pedal is separated far away from the crankshaft so as to enable a strong force to be transmitted to the crankshaft by using the principle of the lever, and thus rotational torque can be increased.