The electric motor is the most important component. Less expensive electric bikes use less expensive, heavier and noisier motors. Brushless motors, which are more modern, lighter and quieter, are used in the best e-bikes. Bosch, Shimano, Broser and Yamaha motors stand out, although other quality motors also exist.
Pedelecs usually have a 250W rated motor power, as this is limited by regulations. The maximum force or torque is between 50 Nm and 90 Nm (Newtons/meter). A high torque offers greater bike agility and reaction, but consumes more battery power, so it is necessary to find a balance. MTB eBikes have the highest torques, because they have to cope with higher gradients and continuous changes of pace
The central motor is the most popular. It is more stable, as its weight is centred, and the riding sensation is similar to a conventional bike. This sort of motor is essential for electric MTB bikes and highly recommended for road and gravel bikes. Motors on the front and rear hubs do not interfere with the drivetrain and provide designs and aesthetics similar to those of conventional bikes. They are used on urban and folding bikes and on some road bikes.
The battery capacity is as important as the motor. It is measured in Watts/hour (Wh) and usually varies between 300 and 700 Wh. Higher quality bikes have a battery integrated into the frame design and offer the possibility of additional or extended batteries to increase the range, in some cases well in excess of 1,000 Wh.
You can view more detailed and extensive information about these components in this article where we explain How to choose an electric bike.