There are many different types of electric bike motors divided by different attributes, for example, 350W or 500W by the motor power, front motor or crank motor by the motor position, etc.
See from the mechanical structure, there are two main types of bike hub motors currently on the market: geared and gearless hub motors (gearless hub motors are also called “direct drive” hub motors). Due to the lack of gears, direct drive hub motors are the simpler of the two, so we’ll start with those.
1. Gearless (direct drive) hub motors
In a direct drive hub motor, the axle that passes through the center of the motor is actually the axle of the motor itself, with the copper windings fixed to the axle. This whole axle assembly is called the “stator”. The magnets are mounted to the outer shell of the hub motor. When electricity is applied to the stator a magnetic field is induced that causes the magnets to move. Thisin turn makes the whole shell of the motor turn and propels the e-bike forward.
2. Geared hub motors
Geared hub motors, on the other hand, have their cases connected to the stator through a planetary gear reduction system. For every rotation of the case, the motor inside actually turns many times faster. This allows the motor to work at higher and more efficient speeds, while still allowing the wheel to spin at a comparatively slower driving speed.
Here below, we will see what is the differences between gearless and geared motors.
Geared e-bikes require a smaller motor in comparison to direct drive and this greatly reduces the weight of the bicycle. This is because gearless bikes have to rely on a big and heavy motor to drive the wheel directly, while geared versions only need small gear system on the wheel.
This makes them more favored by commuters as they are less cumbersome to get on trains and to store at home or in the workplace.
People new to e-bikes also prefer more lightweight models as they similar to the weight of regular bicycles and easier to handle.
Being lighter not only helps the handling but also improves the acceleration. This helps you pull away from a stationary position far more quickly and with less effort.
Going uphill is also easier due to geared bikes being able to produce more torque at lower speeds. This means you can let the power assist do some of the work an upward climb and you won’t need to pedal as much.
On average, geared bikes are capable of going further on a single charge. Direct drive motors are built for maintaining higher speeds, which isn’t always necessary for day to day use. Due to this, the motor sucks more power from the battery.