The two most common types of hub motors used in electric bikes are brushed and brushless. There are many possible types of electric motorized bikes with several technologies available, varying in cost and complexity; direct-drive and gearedmotor units are both used. An electric power-assist system may be added to almost any pedal cycle using chain drive, belt drive, hub motors or friction drive. Brushless DC hub motors are a common modern design with the motor built into the wheel hub itself and the stater fixed solidly to the axle and the magnets attached to and rotating with the wheel. The bicycle wheel hub is the motor. The power levels of motors used are influenced by available legal categories and are often, but not always limited to under 750 watts.
Another type of electric assist motor, often referred to as the mid-drive system, is increasing in popularity. With this system, the electric motor is not built into the wheel but is usually mounted under the bottom bracket shell. In more typical configurations, a cog or wheel on the motor drives a belt or chain that engages with a pulley or sprocket fixed to one of the arms of the bicycle’s crankset. Thus the propulsion is provided at the pedals rather than at the wheel, being eventually applied to the wheel via the bicycle’s standard drive train.
Another type of electric assist motor, often referred to as the mid-drive system, is increasing in popularity. With this system, the electric motor is not built into the wheel but is usually mounted under the bottom bracket shell. In more typical configurations, a cog or wheel on the motor drives a belt or chain that engages with a pulley or sprocket fixed to one of the arms of the bicycle’s crankset. Thus the propulsion is provided at the pedals rather than at the wheel, being eventually applied to the wheel via the bicycle’s standard drive train.
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