There are two basic electric motor for bike types: 1) f […]
There are two basic electric motor for bike types:
1) frame mounted motors
2) in-wheel hub motors
The bulk of e-bikes today are driven by front and or rear wheel hub motors, mostly Brushless DC motors. The external frame mounted motors are typically Currie motors, though there are others too.
Two types of hub motors dominate the field today:
1) Direct drive hub motors
Direct drive DC motors come in all shapes and sizes from computer fan motors to hydroelectric motors found in large dams.The direct drive hub ebike motor is basically a fixed hub laced to a wheel. Inside the hub are windings. When power flows through the windings , the hub and wheel rotates around the axle. These motors are powerful, but heavy.
2) Geared hub motors
As the name implies, geared ebike motors have gears inside of the hub. The gears reduce the speed of the faster spinning motor to match the speed of the wheel. Geared motors are installed in the rear hub. Geared motors rely on gearing (about 5 to 1) to achieve higher torques needed for hill climbing. Geared motors have the advantage of low speed constant torque, but lower top end velocities.