A unitary system for an electric-assist bicycle generates signals indicative of power input to a drive system of the bicycle when a rider pedals the bicycle, considering torque applied by the rider, as well as the cadence or speed of the rider's pedaling. Direction of pedaling is also measured using the system. The system utilizes fixed, hard-wired, contactless electronics, namely first and second inductance coils that are non-equally-spaced circumferentially around a first axis, and which generate a first electrical signal indicative of torque based on lateral movement of a conductive or otherwise magnetically permeable rotatable member relative to the coils, and which generate second and third electrical signals indicative of pedaling cadence and direction based on eccentric relative rotational movement of the conductive or otherwise magnetically permeable rotatable member relative to the first and second inductance coils.

A bicycle includes a bicycle body, a bicycle component, and a battery. The bicycle body has a frame including a down tube, a component mounting portion, and a seat tube. The bicycle component includes a bicycle drive unit. At least a portion of the bicycle component is arranged inside the frame. The battery is mounted on the bicycle to supply the bicycle component with electrical power. The battery has an elongated shape. One end of the battery is entirely accommodated in the down tube, and another end of the battery is disposed outside the down tube.

A bicycle includes a bicycle body, a bicycle component, and a battery. The bicycle body has a frame including a down tube, a component mounting portion, and a seat tube. The bicycle component includes a bicycle drive unit. At least a portion of the bicycle component is arranged inside the frame. The battery is mounted on the bicycle to supply the bicycle component with electrical power. The battery has an elongated shape. One end of the battery is entirely accommodated in the down tube, and another end of the battery is disposed outside the down tube.

A bicycle includes a bicycle body, a bicycle component, and a battery. The bicycle body has a frame including a down tube, a component mounting portion, and a seat tube. The bicycle component includes a bicycle drive unit. At least a portion of the bicycle component is arranged inside the frame. The battery is mounted on the bicycle to supply the bicycle component with electrical power. The battery is accommodated in the down tube. The frame further includes a first open portion to accommodate the bicycle component in the frame. Both the bicycle component and the battery are partly disposed outside the frame via the first open portion.

A bicycle includes a bicycle body, a bicycle component, and a battery. The bicycle body has a frame including a down tube, a component mounting portion, and a seat tube. The bicycle component includes a bicycle drive unit. At least a portion of the bicycle component is arranged inside the frame. The battery is mounted on the bicycle to supply the bicycle component with electrical power. The battery is accommodated in the down tube. The frame further includes a first open portion to accommodate the bicycle component in the frame. Both the bicycle component and the battery are partly disposed outside the frame via the first open portion.

A balance bike conversion system may include first and second protective inserts, each having an interface adapted to engage opposite ends of a bicycle bottom bracket. A connector may be adapted to connect the first and second protective inserts, and may be adapted to adjust the distance between the inserts, thereby accommodating variability in the width of the bottom bracket. The system may further include adapters to enable the system to be used with bicycles having bottom brackets with different diameters, and may use an elastomeric gasket to accommodate larger bottom brackets. The protective inserts and/or adapters may provide mechanical support to the bottom bracket, thereby protecting it from damage.

A balance bike conversion system may include first and second protective inserts, each having an interface adapted to engage opposite ends of a bicycle bottom bracket. A connector may be adapted to connect the first and second protective inserts, and may be adapted to adjust the distance between the inserts, thereby accommodating variability in the width of the bottom bracket. The system may further include adapters to enable the system to be used with bicycles having bottom brackets with different diameters, and may use an elastomeric gasket to accommodate larger bottom brackets. The protective inserts and/or adapters may provide mechanical support to the bottom bracket, thereby protecting it from damage.

A bicycle includes a bicycle body, a bicycle component, and a battery. The bicycle body has a frame including a down tube, a component mounting portion, and a seat tube. The bicycle component includes a bicycle drive unit. At least a portion of the bicycle component is arranged inside the frame. The battery is mounted on the bicycle to supply the bicycle component with electrical power. The battery is accommodated in the down tube. The frame further includes a first open portion to accommodate the bicycle component in the frame. Both the bicycle component and the battery are partly disposed outside the frame via the first open portion.

A bicycle includes a bicycle body, a bicycle component, and a battery. The bicycle body has a frame including a down tube, a component mounting portion, and a seat tube. The bicycle component includes a bicycle drive unit. At least a portion of the bicycle component is arranged inside the frame. The battery is mounted on the bicycle to supply the bicycle component with electrical power. The battery is accommodated in the down tube. The frame further includes a first open portion to accommodate the bicycle component in the frame. Both the bicycle component and the battery are partly disposed outside the frame via the first open portion.

A transmission shaft of an electric vehicle comprises a transmission rod, a five-way base and a rear gearbox. The five-way base comprises a five-way base body, a five-way base cylinder, a left lock ring, and a right cover. The five-way base cylinder is sleeved on the outer peripheral surface of the five-way base body. The left lock ring and the right cover are connected to both ends of the five-way base body by threads. Both ends of the mandrel protrude from the left lock ring and the right cover, respectively, and a five-way gear is sleeved on the surface of the mandrel The five-way gear is rotatably connected to the five-way base body and is meshed with a front transmission gear. The inner peripheral surface of the five-way gear is provided with ratchet teeth.