electric motor

Electric-assist systems have a motor and control system to help give you a boost when you need it.

Generally packaged as a kit with motor, battery, controller, and appropriate cabling.

The main issue is to engage the motor with the drivetrain at the same time as the rider is simultaneously pedalling. The three main ways to accomplish this are:

• direct-drive: the motor is embedded inside a hub of the bike or trike
• inline: the motor is mounted to the frame and drives the chain as it passes through
• mid-drive: the motor drives the main chain to the drivetrain and the rider pedals a separate drive system

The other defining characteristic of a pedal-assist system is how the rider engages the motor. The simplest and easiest system is to give the rider a throttle or Go button. When the rider wants a boost, he / she pushes the button or turns the throttle and the motor engages.

Pedal-assist systems might not have a throttle. Instead, they measure the force on the pedals and then send a signal to the motor to engage or disengage appropriately to the the amount of force measured. This system is more difficult to implement by the electric-assist system, but is much more intuitive to the rider - the rider's efforts are simply amplified.