As the name suggests, the hub motor is built in the hub to directly drive the wheel. Its biggest feature is that the power and transmission devices are integrated into the wheel hub, which greatly simplifies the mechanical part of the electric bicycle, making it more beautiful, lighter and more efficient. In the early days, due to the limitation of precision and material, friction was often generated due to insufficient precision, which caused noise and wear problems. Now with the continuous development of industrial technology, the production of motors has been very sophisticated, overcoming various problems that existed in the early days.
There are two types of hub motors: geared hub motors and gearless hub motors.
The advantage of a geared hub motor (commonly known as a high-speed motor) is the internal design of a clutch device, which makes the resistance of the vehicle coasting or manual pedaling when the electric vehicle is turned off or the battery is empty than the gearless hub motor under the same circumstances. The resistance is smaller. So it is widely used by electric vehicle manufacturers.
The internal structure of a gearless hub motor (commonly known as a low-speed motor) is relatively traditional. There is no duplicate planetary reduction gear. It uses a direct drive type and directly relies on electromagnetic conversion to generate mechanical energy to drive the electric vehicle. The disadvantage is that since there is no clutch device, electromagnetic resistance needs to be overcome when riding without power. Generally speaking, the cost of gearless motors is lower than that of geared motors.