Abstract: A bicycle assist unit is basically provided with a transmission and an assist motor. The transmission is configured to receive rotation of a crankshaft. The transmission includes a planetary gear mechanism. The planetary gear mechanism includes an output unit, a plurality of ring gears and a rotation restricting mechanism that selectively restricts rotation of the ring gears. The assist motor is configured to output a second drive force that is added to a first drive force that is outputted from the transmission on a power transmission path between the output unit and a front sprocket that is attached to the crankshaft.

Abstract: A drive unit has three axles, three rotation transmitting members and an acting force detecting unit. The first axle is configured to be rotated by a crank arm. The first rotation transmitting member is arranged on the first axle to transmit rotation of the first axle by the crank arm. The second axle is spaced from the first axle. The second rotation transmitting member is arranged on the second axle, and is operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member. The third axle is spaced from the first axle and the second axle. The third rotation transmitting member is arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member. The acting force detecting unit arranged to detect a force acting on the second axle.

Abstract: A bicycle assist unit is basically provided with a transmission and an assist motor. The transmission is configured to receive rotation of a crankshaft. The transmission includes a planetary gear mechanism. The planetary gear mechanism includes an output unit, a plurality of ring gears and a rotation restricting mechanism that selectively restricts rotation of the ring gears. The assist motor is configured to output a second drive force that is added to a first drive force that is outputted from the transmission on a power transmission path between the output unit and a front sprocket that is attached to the crankshaft.

Abstract: A bicycle drive unit includes a crank axle, a motor, an output member and a torque combining mechanism. The crank axle is rotatable about a first rotational axis. The motor has an output shaft rotatable about a second rotational axis. The output member is rotatable about the first rotational axis in a first rotational direction as the crank axle rotates about the first rotational axis in the first rotational direction. The torque combining mechanism operatively couples the output shaft of the motor to the output member to transmit rotation of the output shaft of the motor to the output member. The torque combining mechanism operatively separates the output shaft of the motor from the output member for preventing rotation of the crank axle from being transmitted to the output shaft of the motor as the crank axle rotates about the first rotational axis in a second rotational direction.

Abstract: A bicycle drive unit includes a motor, a transmission mechanism and a torque combining member. The motor includes a crank axle receiving hole. The transmission mechanism includes a plurality of selectable gear ratios. The torque combining member is operatively coupled to the motor and the transmission mechanism to combine an output of the motor and an output of the transmission mechanism together.

Abstract: A bicycle drive unit includes a crank axle, a motor, an output member and a torque combining mechanism. The crank axle is rotatable about a first rotational axis. The motor has an output shaft rotatable about a second rotational axis. The output member is rotatable about the first rotational axis in a first rotational direction as the crank axle rotates about the first rotational axis in the first rotational direction. The torque combining mechanism operatively couples the output shaft of the motor to the output member to transmit rotation of the output shaft of the motor to the output member. The torque combining mechanism operatively separates the output shaft of the motor from the output member for preventing rotation of the crank axle from being transmitted to the output shaft of the motor as the crank axle rotates about the first rotational axis in a second rotational direction.

Abstract: A bicycle drive unit includes a motor, a crank axle, a torque combining mechanism, and a clutch mechanism. The crank axle is rotatable about a first rotational axis. The torque combining mechanism is operatively coupled to the motor and the crank axle. The torque combining mechanism has a sprocket mounting portion that is configured to be operatively attached to a sprocket such that the sprocket rotates about a second rotational axis of the sprocket in a first direction as the crank axle rotates about the first rotational axis in the first direction. The clutch mechanism is operatively disposed between the crank axle and the sprocket. The clutch mechanism is configured to rotate the sprocket about the second rotational axis in a second direction as the crank axle rotates about the first rotational axis in the second direction. The second direction is opposite the first direction.

Abstract: A bicycle drive unit includes a motor, a crank axle, a torque combining mechanism, and a clutch mechanism. The crank axle is rotatable about a first rotational axis. The torque combining mechanism is operatively coupled to the motor and the crank axle. The torque combining mechanism has a sprocket mounting portion that is configured to be operatively attached to a sprocket such that the sprocket rotates about a second rotational axis of the sprocket in a first direction as the crank axle rotates about the first rotational axis in the first direction. The clutch mechanism is operatively disposed between the crank axle and the sprocket. The clutch mechanism is configured to rotate the sprocket about the second rotational axis in a second direction as the crank axle rotates about the first rotational axis in the second direction. The second direction is opposite the first direction.

Abstract: A drive unit has three axles, three rotation transmitting members and an acting force detecting unit. The first axle is configured to be rotated by a crank arm. The first rotation transmitting member is arranged on the first axle to transmit rotation of the first axle by the crank arm. The second axle is spaced from the first axle. The second rotation transmitting member is arranged on the second axle, and is operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member. The third axle is spaced from the first axle and the second axle. The third rotation transmitting member is arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member. The acting force detecting unit arranged to detect a force acting on the second axle.

Abstract: A bicycle drive unit basically includes a motor and a crank axle torsion sensor unit. The motor has a crank axle receiving hole that is arranged for installing a crank axle. The crank axle torsion sensor unit is at least partially disposed inside of the crank axle receiving hole in between the motor and the crank axle.

Abstract: A bicycle drive unit includes a motor, a transmission mechanism and a torque combining member. The motor includes a crank axle receiving hole. The transmission mechanism includes a plurality of selectable gear ratios. The torque combining member is operatively coupled to the motor and the transmission mechanism to combine an output of the motor and an output of the transmission mechanism together.

Abstract: A planetary gear mechanism for a bicycle internal hub transmission that includes at least one stepped planetary gear. The stepped planetary gear has a plurality of first helical gear teeth with a first outer diameter and a plurality of second helical gear teeth with a second outer diameter that is greater than the first outer diameter. The first helical gear teeth have a first helix angle and the second gear teeth have a second helix angle with the first and second helix angles being angled such that for a given amount of rotation of the stepped planetary gear corresponding travel points on the first and second helical gear teeth move the same axial amount with respect to the rotational axis the stepped planetary gear.

Abstract: An internal hub transmission includes a hub axle, a driver rotatably supported by the hub axle, a hub shell rotatably supported by the hub axle, a power transmission mechanism and a shift mechanism. The power transmission mechanism is disposed between the driver and the hub shell for transmitting rotational power from the driver to the hub shell through a plurality of power transmission paths. The power transmission mechanism has at least one planetary gear mechanism that includes a sun gear, a planetary gear and a gear ring. The planetary gear is supported by a gear rack. The planetary gear has helical gear teeth and at least one of the sun gear and the gear ring is provided with helical gear teeth that mesh to helical gear teeth of the planetary gear.

Abstract: A multi-speed internal bicycle hub transmission assembly includes a stationary hub axle, a driver, a hub shell, a power transmission mechanism and a shift control mechanism. The stationary hub axle includes a positioner that is movable in a radial direction. The driver and the hub shell are rotatably supported to the hub axle. The power transmission mechanism is operably disposed between the driver and the hub shell for transmitting rotational power from the driver to the hub shell through a plurality of power transmission paths. The shift control mechanism includes a pawl control member movable in rotational directions relative to the hub axle to a plurality of orientations. Each orientation corresponds to selection of a corresponding one of the plurality of power transmission paths of the power transmission mechanism. The positioner is disposed to urge the pawl control member to remain the selected orientation.

Abstract: A shift control apparatus for a bicycle comprises an output transmission member that moves to at least a first output position and a second output position, a position maintaining mechanism, and a release control mechanism. The position maintaining mechanism includes a position maintaining member that moves between a position maintaining position and a position release position, wherein the position maintaining position maintains the output transmission member in one of the first output position and the second output position. The position release position allows the output transmission member to move toward the other one of the first output position and the second output position. The release control mechanism includes a release member that moves between a first release member position and a second release member position.

Abstract: A bicycle hub transmission includes a hub axle, a driver, a hub shell, a power transmission mechanism and a shift mechanism. The driver and the hub shell are rotatably supported relative to the hub axle. The power transmission mechanism is disposed between the driver and the hub shell to selectively transmit rotational power from the driver to the hub shell through one a plurality of power transmission paths. The shift mechanism operatively couples the power transmission mechanism to select a power transmission path. The downstream planetary gear unit includes a planetary gear carrier that meshes with planetary gears of the upstream planetary gear unit or with a linking member coupled to the planetary gears of the upstream planetary gear unit. The planetary gear carrier of the downstream planetary gear unit is coupled with a brake unit to transmit a reverse rotational power from the driver to the brake unit.

Abstract: A planetary gear mechanism for a bicycle internal hub transmission that includes at least one stepped planetary gear. The stepped planetary gear has a plurality of first helical gear teeth with a first outer diameter and a plurality of second helical gear teeth with a second outer diameter that is greater than the first outer diameter. The first helical gear teeth have a first helix angle and the second gear teeth have a second helix angle with the first and second helix angles being angled such that for a given amount of rotation of the stepped planetary gear corresponding travel points on the first and second helical gear teeth move the same axial amount with respect to the rotational axis the stepped planetary gear.

Abstract: A bicycle hub transmission basically includes a hub axle, a driver, a hub shell, a power transmission mechanism and a shift mechanism. The driver is rotatably supported relative to the hub axle. The hub shell is rotatably supported relative to the driver. The power transmission mechanism includes a downstream planetary gear unit and an upstream planetary gear unit disposed between the driver and the hub shell to selectively transmit rotational power from the driver to the hub shell through one a plurality of power transmission paths. The shift mechanism is operatively coupled to the power transmission mechanism to select one of the power transmission paths. The downstream planetary gear unit includes at least a planetary gear carrier that meshes with planetary gears of the upstream planetary gear unit.

Abstract: A bicycle hub transmission basically includes a hub axle, a driver, a hub shell, a power transmission mechanism and a shift mechanism. The driver is rotatably supported relative to the hub axle. The hub shell is rotatably supported relative to the driver. The power transmission mechanism includes a downstream planetary gear unit and an upstream planetary gear unit disposed between the driver and the hub shell to selectively transmit rotational power from the driver to the hub shell through one a plurality of power transmission paths. The shift mechanism is operatively coupled to the power transmission mechanism to select one of the power transmission paths. The downstream planetary gear unit includes at least a first sun gear, a second sun gear and a planetary gear carrier that meshes with planetary gears of the upstream planetary gear unit.

Abstract: A multi-speed internal bicycle hub transmission assembly includes a stationary hub axle, a driver, a hub shell, a power transmission mechanism and a shift control mechanism. The stationary hub axle includes a positioner that is movable in a radial direction. The driver and the hub shell are rotatably supported to the hub axle. The power transmission mechanism is operably disposed between the driver and the hub shell for transmitting rotational power from the driver to the hub shell through a plurality of power transmission paths. The shift control mechanism includes a pawl control member movable in rotational directions relative to the hub axle to a plurality of orientations. Each orientation corresponds to selection of a corresponding one of the plurality of power transmission paths of the power transmission mechanism. The positioner is disposed to urge the pawl control member to remain the selected orientation.