There are two basic electric motor for bike types: frame mounted motors, and in-wheel hub motors. The bulk of e-bikes today are driven by front and or rear wheel hub motors. The external frame mounted motors are typically Currie motors, though there are others.
Either type will get the job done, though the hub motors are more streamlined, and are fast becoming the motor of choice. The hub motor uses the casing of the motor as the hub itself. We deal mostly with hub motors on this site.
With hub motors, the motor is built into the wheel hub itself with the stator fixed directly to the axle. The magnets are attached to and rotate with the wheel. The bicycle wheel hub is the motor.
Two types of hub motors dominate the field today: Direct drive and Geared motors.
Direct Drive
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.
Geared 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.
Electric Motor for Bike
On the previous page, we discussed electric motor for bike power. This page reviews the ebike motor itself and some of the costs.
Electric bike motors range from a few hundred Watts to the 72 Volt Crystalyte lineup at 2880 Watts. Notice that 2,880 watts is 3.8 Horsepower. That is the power of many electric scooters. This much power exceeds 98% or more of world ebike legal power limits.
With all the different ebike motors and kits, it can be confusing as to what to get. How much power do you need to get around? How much can you afford?
Crystalyte motor in wheel
fast but heavy at 24 pounds!
Direct Drive Motor
Geared Motor
Power
Up to 2880 Watts
Up to 1000 Watts
Speed
40mph/64kph plus
25mph/40kph plus
Weight
15-25lbs / 7-11kg
7-10lbs / 3-4.5kg
Size
9.2in / 234 mm
5.2in / 134 mm
Motor Power and manufacturers
Direct drive hub motors are available in power ratings from about 200 to 2,880 Watts. Voltage inputs vary from 24 to 72 volts. Current input varies with the battery and controller used.
Performance of these motors varies from about 15mph/20kph to over 50mph/80kph!
There are many manufacturers of these motors. Some of them are listed on the next pages.
Geared hub motors vary from about 250 to 1,000 watts, though some advertise higher peak power draw. Some of them are also listed on the next pages.
