What Is a Torque Sensor?

A torque sensor measures the torque applied to a rotating shaft by converting the torque into an electrical signal. It works by applying force to a flexible shaft that is connected to a strain gauge.

The strain gauge measures the tiny twist or deformation of the shaft, which is proportional to the applied torque. This electrical signal is then amplified, filtered, and processed to provide an accurate measurement of the torque.

The output of the torque sensor can be used for various applications such as controlling the speed of motors, monitoring the functioning of machinery, and guaranteeing the safety of industrial processes.

This also applies to an electric bike.

The torque sensor on an e-bike measures the force applied by the rider to the pedals and converts it into an electrical signal. The signal is then used to control the assistance provided by the bike’s electric motor.

The sensor often consists of a strain gauge mounted on the bike. Typically, on the rotating shaft/spindle or on a stationary part close to or inside the crank. The strain gauge picks up the tiny twist caused by the rider’s pedaling force, which is proportional to the torque applied to the pedals.

After the electrical signal is amplified and filtered it is sent to the e-bike’s motor controller, which uses the information to adjust the assistance provided by the motor in real-time. This ensures that the rider has a natural and intuitive riding experience. Also, it maximizes the efficiency and range of the e-bike, as the assistance matches the rider’s effort. This reduces the amount of energy wasted and the battery consequently has a longer range.