Chain-rings set for bicycle including a first chain-ring and a second chain-ring, this latter formed by segments, which includes displacement means with axial component of the segments with respect to the first chain-ring such that they can be moved a the chain free zone ZLC and shift the chain among chain-rings, where the axial displacement means are formed by guiding means configured for guiding the segments such that the relative movement of the teeth of the segments with respect to the small chain-ring in its displacement from a first disengagement configuration to a second engagement configuration has a tangential component opposite to the forward direction.

Chain-rings set for bicycle including a first chain-ring and a second chain-ring, this latter formed by segments, which includes displacement means with axial component of the segments with respect to the first chain-ring such that they can be moved a the chain free zone ZLC and shift the chain among chain-rings, where the axial displacement means are formed by guiding means configured for guiding the segments such that the relative movement of the teeth of the segments with respect to the small chain-ring in its displacement from a first disengagement configuration to a second engagement configuration has a tangential component opposite to the forward direction.

A control device for a human-powered vehicle including a motor that applies a propulsion force to the human-powered vehicle, a crank axle, a driving wheel, and a transmission that automatically changes a transmission ratio of a rotational speed of the driving wheel to a rotational speed of the crank axle in accordance with a travel state of the human-powered vehicle. The control device includes an electronic controller that controls the motor in accordance with a human driving force input to the crank axle. The controller changes an assist state related to at least one of an assist ratio of an assist force by the motor to a predetermined human driving force and the assist force by the motor in accordance with the human driving force and controls the transmission to maintain the transmission ratio upon determining a parameter related to the human driving force satisfies a predetermined condition.

A control device for a human-powered vehicle including a motor that applies a propulsion force to the human-powered vehicle, a crank axle, a driving wheel, and a transmission that automatically changes a transmission ratio of a rotational speed of the driving wheel to a rotational speed of the crank axle in accordance with a travel state of the human-powered vehicle. The control device includes an electronic controller that controls the motor in accordance with a human driving force input to the crank axle. The controller changes an assist state related to at least one of an assist ratio of an assist force by the motor to a predetermined human driving force and the assist force by the motor in accordance with the human driving force and controls the transmission to maintain the transmission ratio upon determining a parameter related to the human driving force satisfies a predetermined condition.

A system and method for simple transmission of a multi-speed bicycle is provided. A bicycle can have a transmission that can be toggled by a kickback shifting mechanism. A rear wheel hub can support a freewheel having a high speed gear sprocket and a low speed gear sprocket with dedicated chains to create dedicated gear-shifting. Rotating the pedal shaft in the non-drive direction approximately one-quarter rotation can toggle the transmission between the first gear ratio and the second gear ratio with a shifting surface that alternately allows driving engagement of the high speed gear sprocket with the rear wheel driver.

A system and method for simple transmission of a multi-speed bicycle is provided. A bicycle can have a transmission that can be toggled by a kickback shifting mechanism. A rear wheel hub can support a freewheel having a high speed gear sprocket and a low speed gear sprocket with dedicated chains to create dedicated gear-shifting. Rotating the pedal shaft in the non-drive direction approximately one-quarter rotation can toggle the transmission between the first gear ratio and the second gear ratio with a shifting surface that alternately allows driving engagement of the high speed gear sprocket with the rear wheel driver.

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 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, such that a gear ratio of the gearbox is changeable without displacing the belt out of the plane.

A human-powered vehicle control device includes an electronic controller configured to control a transmission that changes a transmission ratio of a rotational speed of a wheel of a human-powered vehicle to a rotational speed of a crank of the human-powered vehicle. The electronic controller is configured to control the transmission to change the transmission ratio in accordance with a comparison of a parameter related to at least one of a traveling environment and a traveling state of the human-powered vehicle with a predetermined determination value. The electronic controller is configured to change the predetermined determination value in accordance with a change in the parameter during a single rotation of the crank.

A straddle-type vehicle (100) includes a frame (20) and an engine (10) mounted on the frame (20), the engine (10) includes a cylinder head (11) positioned toward the rear end of the frame, and located below a saddle seat (80). The cylinder head laces toward the rear end of the frame, which allows the heated cylinder head of the engine and the exhaust pipe connected to the cylinder head to avoid contact with the vehicle the user's legs while riding the vehicle, so the effect of heat emitted from the cylinder head on the rider's experience is reduced.

A straddle-type vehicle (100) includes a frame (20) and an engine (10) mounted on the frame (20). The engine (10) includes a cylinder head (11) positioned toward the rear end of the frame, and located below a saddle seat. The cylinder head faces toward the rear end of the frame, which allows the heated cylinder head of the engine and the exhaust pipe connected to the cylinder head to avoid the position where the user's legs contact the vehicle while riding, so the effect of heat emitted from the cylinder head on the rider's experience is reduced.