Bicycle

A bicycle comprising:

• a vehicle-body frame;
• a front wheel rotatably supported by the vehicle-body frame and that is a steered wheel;
• a rear wheel rotatably supported by the vehicle-body frame;
• a crankshaft rotatably supported by the vehicle-body frame;
• a pedal connected to the crankshaft to rotate together with the crankshaft;
• a transmission to transmit rotation of the pedal to the rear wheel;
• a motor to apply at least a torque to cause rearward rotation of at least one of the front wheel or the rear wheel;
• a roll detector to detect at least one of a roll angle or a roll angular velocity of the vehicle-body frame;
• and
• a steering detector to detect a direction of steering of the front wheel;
• wherein
• when a vehicle speed in a forward direction of the bicycle is zero and a steering angle of the front wheel is not zero, the motor applies, to the at least one of the front wheel or the rear wheel, a torque to maintain the roll angle of the vehicle-body frame based on the direction of steering detected by the steering detector and the at least one of the roll angle or the roll angular velocity of the vehicle-body frame of the bicycle detected by the roll detector;
• and
• the transmission is operable to transmit both forward rotation and rearward rotation of the rear wheel to the pedal.

A bicycle comprising:

• a vehicle-body frame;
• a front wheel rotatably supported by the vehicle-body frame and that is a steered wheel;
• a rear wheel rotatably supported by the vehicle-body frame;
• a crankshaft rotatably supported by the vehicle-body frame;
• a pedal connected to the crankshaft to rotate together with the crankshaft;
• a transmission to transmit rotation of the pedal to the rear wheel;
• a motor to apply at least a torque to cause rearward rotation of at least one of the front wheel or the rear wheel;
• a roll detector to detect at least one of a roll angle or a roll angular velocity of the vehicle-body frame;
• and
• a steering detector to detect a direction of steering of the front wheel;
• wherein
• when a vehicle speed in a forward direction of the bicycle is zero and a steering angle of the front wheel is not zero, the motor applies, to the at least one of the front wheel or the rear wheel, a torque to maintain the roll angle of the vehicle-body frame based on the direction of steering detected by the steering detector and the at least one of the roll angle or the roll angular velocity of the vehicle-body frame of the bicycle detected by the roll detector;
• when the vehicle speed in the forward direction of the bicycle is zero and the steering angle of the front wheel is not zero, the motor is controlled to apply a torque to cause forward rotation of the at least one of the front wheel or the rear wheel when the vehicle-body frame is about to tilt toward a direction to which the front wheel is steered;
• and
• the motor is controlled to apply the torque to cause rearward rotation of the at least one of the front wheel or the rear wheel when the vehicle-body frame is about to tilt toward a direction opposite to the direction to which the front wheel is steered.