For the electric bicycle, in addition to the number of indicators, there are general requirements, such as safety, braking, driving a smooth and comfortable, smooth speed control, vibration, low noise, light weight, looks good, looks nice, etc. no longer described.
However, the current within the industry, in the middle of widespread consumer awareness and many incorrect statement, if not clarified and corrected, will inevitably affect the electric bicycle industry.
The first is the electric bicycle motor power choice.
Power is not better, electrical power from the vehicle weight, load and speed decisions. GB 17,761 pairs of vehicle weight, the standard load and speed have made it clear that: the quality of their vehicle should be less than 40Kg, the standard load 75 Kg, the maximum speed should not exceed 20 Km / h. In such conditions, electric bicycle driven by the measured and calculated power is only 110W, the use of low-speed direct-drive motor-driven approach, taking into account the power margin, use the rated output power of 120W motor can. If using other drive, must take account of the efficiency of transmission of the drive to select the motor power.
Power considerations in the choice of only the maximum speed under power required to run smoothly, without taking into account the increase in climbing and driving wind power, this part of the power from the motor overload commitment. Such as climbing and driving wind and the probability of driving compared to normal, after all, usually much less. If climbing, wind power and other computing and select the motor, the motor power may be increased several times, and this costs a lot of motor manufacturers on the one hand, while in normal driving because of low load, resulting in low efficiency, which will significantly shorten the charging time driving range.