E-bikes are classed according to the power that their electric motor can deliver and the control system, i.e., when and how the power from the motor is applied. Also the classification of e-bikes is complicated as much of the definition is due to legal reasons of what constitutes a bicycle and what constitutes a moped or motorcycle. As such, the classification of these e-bikes varies greatly across countries and local jurisdictions.
Despite these legal complications, the classification of e-bikes is mainly decided by whether the e-bike’s motor assists the rider using a pedal-assist system or by a power-on-demand one. Definitions of these are as follows:
With pedal-assist the electric motor is regulated by pedalling. The pedal-assist augments the efforts of the rider when they are pedalling. These e-bikes – called pedelecs – have a sensor to detect the pedalling speed, the pedalling force, or both. Brake activation is sensed to disable the motor as well.
With power-on-demand the motor is activated by a throttle, usually handlebar-mounted just like on most motorcycles or scooters.
Therefore, very broadly, e-bikes can be classed as:
- E-bikes with pedal-assist only: either pedelecs (legally classed as bicycles) or S-Pedelecs (often legally classed as mopeds)
- Pedelecs: have pedal-assist only, motor assists only up to a decent but not excessive speed (usually 25 km/h), motor power up to 250 watts, often legally classed as bicycles
- S-Pedelecs: have pedal-assist only, motor power can be greater than 250 watts, can attain a higher speed (e.g., 45 km/h) before motor stops assisting, legally classed as a moped or motorcycle (not a bicycle)
- E-bikes with power-on-demand and pedal-assist
- E-bikes with power-on-demand only: often have more powerful motors than pedelecs but not always, the more powerful of these are legally classed as mopeds or motorcycles