One of the most important decisions you have to make when choosing an electric bike is whether to go for a mid-drive or wheel hub motor design. The motor type plays a crucial role in the price, ride quality, and overall performance of the bike.
Electric hub motor for cycles are motors that are built into one of the bike's wheels. The wheel hub motor replaces the standard hub. Usually, the motor is installed in the rear, but it can also be installed in the front. The wheel hub motor supplies power directly to its integrated wheel. In other words, it applies torque directly to the wheel without the need for a power transmission system. The wheel hub motor operates completely separately from the bike's drivetrain. It is not affected by shifting. So far, wheel hub motors are the most common type of electric bike motor.
There are two types of wheel hub motors: geared and direct drive. Direct drive wheel hub motors have no moving parts except for the wheel bearings. They are mechanically simple. Direct drive motors are common on entry-level electric bikes. Direct drive wheel hub motors are also called direct drive. Geared wheel hub motors use internal planetary gears to reduce the motor's speed. Gears allow a smaller motor to produce more power, thereby increasing efficiency. These motors are more complex. They are common on high-end electric hub motor for cycles. Most electric hub motor for cycles come with a pedal-assist system based on a pedaling sensor. The pedaling sensor measures whether you are pedaling or not. Some models also measure your pedaling speed.
When you start pedaling, the sensor sends a signal to the bike's control unit. The control unit then turns on the wheel hub motor. When you stop pedaling, the sensor sends a signal to the control unit, and the motor turns off. High-end electric hub motor for cycles are equipped with torque sensor pedal-assist systems.
Most wheel hub motors provide constant power while you're pedaling. The motor turns on or off. Some hub-drive electric bikes allow you to adjust the level of pedal assistance. There may be 3-5 assist settings. At level 1, the least amount of assistance is provided. At level 5, the motor runs at full power. On high-end models, the system may adjust automatically based on your cadence. When you start pedaling, the motor runs at full power. As you reach your cadence threshold, the power decreases. Some electric hub motor for cycles also have a throttle control. The throttle is mounted on the handlebars. You use your finger to manipulate the throttle to control the motor's speed. When using the throttle, you don't have to pedal.