In the geared motor, a small and lightweight motor spins very fast inside. The electric bike motor then uses a planetary reduction gear inside the motor to reduce the rpm to the correct speed for a bike wheel. Electric Bike Motor An electric bike motor on an electric bike can be any kind of electric motor. There have been some very creative home brew e bikes that used any motor...
Controllers for brushed motors: Brushed motors are also used in e-bikes but are becoming less common due to their intrinsic lower efficiency. Controllers for brushed motors however are much simpler and cheaper due to the fact they don't require hall sensor feedback and are typically designed to be open-loop controllers. Some controllers can handle multiple voltages.
For many bikes, battery range is more important that total power (because they're all pretty powerful). You want a bike that delivers a range long enough for your rides at the power levels you want. Most e-bikes will have three to five levels of assist kicking in anywhere from 25 percent of you pedal power to 200 percent boost. Consider how fast the battery takes to recharge, especially if you'll be using your bike for long commutes.