What Is a Crank Angle Sensor?

A crank angle sensor provides information about the angle of the crank relative to the frame. The motor controller algorithm uses this information to improve the ride feel. For e-bikes with internal gears, the angle can also be important to control when the gear shifting happens. Having a crank angle sensor on an e-bike is a big step up from a traditional cadence sensor.

The way crank angle sensors for e-bikes are designed is in principle not any different from angle sensors for other purposes. There are a number of different technologies when it comes to angle sensors. Some angle sensors are absolute sensors, meaning they know the angle right from power-on without having to pass an index location first. Some types count pulses either optically or by magnets, whereas others rely on capacitive or inductive coupling to sense the angle between two parts. In crank power meters for sports bikes, it is quite common to use an inclinometer or accelerometer to detect crank angle for cadence calculations (essential for power calculation).

Our combined torque and angle sensor is using a very compact inductive principle to do all of the angle sensing, power transfer, and data communication between the two parts. This concept is quite unique and fits perfectly with what is needed for a great e-bike (this technology is also patented by us).