Diffrent countries have diffrent standards for electric bike, it is necessary to learn basic electric bike standard in your area.
European Union definition
Cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of 0.25 kW, of which the output is progressively reduced and finally cut off as the vehicle reaches a speed of 25km/h (15.5mph) or if the cyclist stops pedaling.
The e-bike can have a motor of 250W of continuous rated power which can only be activated by pedalling (if above 6 km/h) and must cut out over 25 km/h – if so it is classed as a normal bicycle.an auxiliary motor with a maximum power output not exceeding 200 W without consideration for speed limits or pedal sensors.
Eight provinces of Canada allow electric power assisted bicycles. In all eight provinces, e-bikes are limited to 500 W output, and cannot travel faster than 32 km/h (20 mph) on motor power alone on level ground.
United States standard
Different states have diffrent standard about electric bike,the federal Consumer Product Safety Act defines a “low speed electric bicycle” as a two or three wheeled vehicle with fully operable pedals, a top speed when powered solely by the motor under 20 mph (32 km/h) and an electric motor that produces less than 750 W (1.01 hp).
Shuangye produces diffrent models electric to meet with the diffrent countries standard, you can contact us for imfromation freely.