An electric assist system usable for an electric assist bicycle includes an electric motor that generates assist power assisting human power of a rider of the electric assist bicycle, a rotation sensor that outputs a signal in accordance with a rotation of a rotatable component that rotates to operate the electric assist bicycle, an acceleration sensor that outputs a signal in accordance with an acceleration of the electric assist bicycle in a traveling direction thereof, and a controller that calculates a speed of the electric assist bicycle based on an output signal of the rotation sensor and an output signal of the acceleration sensor.

A derailleur comprises a base member configured to be attached to a human-powered vehicle frame, a movable member movable with respect to the base member, a pulley assembly pivotally attached to the movable member in a first pivotal direction and a second pivotal direction opposite to the first pivotal direction and including a first pulley having a first pulley axis and a second pulley having a second pulley axis, a pulley assembly biasing member configured to bias the pulley assembly with respect to the movable member in the first pivotal direction, a pulley distance (centimeter) being defined between the first pulley axis and the second pulley axis, a biasing return force (newton) being defined by rotational force of the pulley assembly relative to the movable member, and a return value defined by the biasing return force multiplied by the pulley distance. The return value is 136 or larger.

A harmonic ring gear system can include at least one inner gear with external toothing, the at least one inner gear defining an axis of rotation; at least one outer gear with internal toothing arranged concentrically to the at least one inner gear about the axis of rotation, the internal toothing spaced apart from the external toothing; a pin ring positioned between the at least one inner gear and the at least one outer gear, the pin ring comprising a multiplicity of pins; and a rotary transmitter configured to lift a portion of the pins of the multiplicity of pins off the external toothing and press the portion of the pins into the internal toothing.

An operating device is provided for a human-powered vehicle. The operating device basically includes a base, a first operating member, a first electric switch, a first load generator and an operating load adjuster. The first operating member is movably arranged with respect to the base. The first electric switch is provided to the base and arranged to be activated by movement of the first operating member. The first load generator is configured to generate an operating load applied to the first operating member. The operating load adjuster is configured to adjust a transition of the operating load from a first load transition to a second load transition different from the first load transition.

A motor unit includes a case, a motor, an input shaft, an input body, an output body, and a speed reducer mechanism. The input shaft penetrates through the case in an axial direction and is arranged to be rotatable. The input body is disposed along an outer peripheral surface of the input shaft and rotates along with the input shaft. The output body is arranged along the outer peripheral surface of the input shaft to be rotatable and receives rotational force from the input body. The case includes a first bearing, a second bearing, and a third bearing. The first bearing is located at one end in an axial direction and supports a rotary shaft unit including the input shaft, the input body, and the output body. The second bearing is located at the other end in the axial direction and supports the rotary shaft unit. The third bearing is located between the first bearing and the second bearing in the axial direction and supports at least one of the input body or the output body.

A motor unit includes a case, a motor, an input shaft, an input body, an output body, and a speed reducer mechanism. The input shaft penetrates through the case in an axial direction and is arranged to be rotatable. The input body is disposed along an outer peripheral surface of the input shaft and rotates along with the input shaft. The output body is arranged along the outer peripheral surface of the input shaft to be rotatable and receives rotational force from the input body. The case includes a first bearing, a second bearing, and a third bearing. The first bearing is located at one end in an axial direction and supports a rotary shaft unit including the input shaft, the input body, and the output body. The second bearing is located at the other end in the axial direction and supports the rotary shaft unit. The third bearing is located between the first bearing and the second bearing in the axial direction and supports at least one of the input body or the output body.

A motor unit, which is an example of an embodiment, includes a motor including a motor shaft, a rotor fixed to the motor shaft, and a stator, and a control board, the control board being disposed with at least a part of the control board overlapping the motor when viewed in a motor axial direction. A sensor that detects a magnetic field of the motor shaft, the rotor, or a rotating body rotating together with the motor shaft, and a control element that controls the motor using detection information of the sensor, are mounted on the control board. The control board includes a signal line that connects the sensor and the control element. The signal line includes an arcuate wiring section bent to be convex in a radial direction outer side of a circle centering on a shaft core of the motor shaft.

An auxiliary power device adapted for use with a bicycle includes a drive unit, first and second one-way transmissions that are adapted to be mounted in a bike frame of the bicycle, a crankshaft and a transmission sprocket. The first one-way transmission is connected between the drive unit and the transmission sprocket. The second one-way transmission is mounted between the crankshaft and the transmission sprocket. When rotation of the transmission sprocket is driven by the drive unit via the first one-way transmission, the second one-way transmission is idling. When rotation of the transmission sprocket is driven by the crankshaft via the second one-way transmission, the first one-way transmission is idling.

An auxiliary power device adapted for use with a bicycle includes a drive unit, first and second one-way transmissions that are adapted to be mounted in a bike frame of the bicycle, a crankshaft and a transmission sprocket. The first one-way transmission is connected between the drive unit and the transmission sprocket. The second one-way transmission is mounted between the crankshaft and the transmission sprocket. When rotation of the transmission sprocket is driven by the drive unit via the first one-way transmission, the second one-way transmission is idling. When rotation of the transmission sprocket is driven by the crankshaft via the second one-way transmission, the first one-way transmission is idling.

The invention is a double motor power unit, suitably for being mounted onto a bicycle frame, which is fitted with at least two motors (7), at least one power supply (13), bearings (8), crank shaft pinion gearhead (11), at least one propulsor pinion gearhead (10) for each motor, at least one planetary gearbox (15) for each motor, and at least one central processor unit (12). It is characterized in that the propulsor pinion gearheads (10) are connected to pinions with dynamometric system (19), having an at least approximately identical axis, and to planetary gearboxes (15) through the pinions, while the inside of the bearings (8) is in fixed connection with the crank shaft (9) and the outside of the bearing (8) is in fixed connection with the crank shaft pinion gearhead (11). The invention is also the procedure for placing the power unit according to claim suitably into a bicycle frame.