pedalassist

Pedalassist, also written pedal assist or pedal-assist, is a feature in electric bicycles and related vehicles where motor power is provided in response to the rider’s pedaling. The system is designed to aid propulsion only when the rider is actively pedaling, and the amount of assistance is typically adjustable. Pedal assist contrasts with throttle-based systems, which may deliver power without pedaling.

Most pedal-assist systems use sensors to measure pedaling input. Cadence sensors detect crank rotation speed, while torque or power sensors gauge the force applied to the crank. The control unit combines sensor data to regulate an electric motor, which can be located in a rear hub, front hub, or mid-drive unit. Motors are commonly rated around 250 watts in many jurisdictions, with higher specifications permitted in some markets. Legal limits on power and assisted speed vary: in the European Union, pedelecs are typically limited to 250 watts and up to 25 km/h of assisted speed; in the United States, classifications define pedal-assist bicycles with different speed caps, such as Class 1 up to 20 mph and Class 3 up to 28 mph.

Operating modes often include multiple assist levels, with some systems adjusting automatically based on torque sensor input. Most pedal-assist bikes do not require a throttle, but some models offer an optional throttle or combined control.

Benefits of pedal assist include extended range, easier climbing, and greater accessibility for riders with limited mobility or endurance. Limitations can include added weight, higher cost, and reliance on battery life, as well as differences in performance depending on sensor accuracy and system design.