How Does Electric Bike Cadence Sensor Work?

How Does Electric Bike Cadence Sensor Work?


An electric bike cadence sensor is a device that detects the pedaling speed of the rider. It operates on the principle that when a rider pedals, magnets on the crank pass by a Hall effect sensor, generating pulse signals. The frequency of these pulse signals is proportional to the pedaling speed. By measuring the frequency of the pulse signals, the pedaling speed can be determined.


Primary Function

The primary function of an electric bike cadence sensor is to control the electric assist system. It serves the following purposes:

  1. Detecting Pedaling Intent: When a rider starts pedaling, the cadence sensor sends a signal, and the electric assist system engages, providing assistance to the rider.
  2. Adjusting Assist Level: The level of assistance provided by the electric assist system can be adjusted based on the pedaling speed. Higher pedaling speeds result in greater assistance, while lower speeds lead to less assistance.
  3. Limiting Top Speed: The top speed of the electric assist system can be restricted using the cadence sensor. Once the pedaling speed reaches a predetermined value, the electric assist system disengages, and the motor stops providing assistance.


Types of Electric Bike Cadence Sensors

There are three main types of electric bike cadence sensors:

  1. Magnetic Cadence Sensor: This is the most common type of cadence sensor due to its simple structure and low cost.
  2. Optical Cadence Sensor: This type of sensor offers higher accuracy but at a higher cost.
  3. Hall Effect Cadence Sensor: This type of sensor provides the highest accuracy but has the most complex structure and highest cost.


Benefits of Electric Bike Cadence Sensors

The incorporation of electric bike cadence sensors has enhanced the control of electric assist systems, providing riders with a more comfortable and natural riding experience. The cadence sensor allows the system to:

  • Respond to Rider Intention: The system automatically activates when the rider starts pedaling, eliminating the need for manual activation.
  • Adjust Assistance to Rider Effort: The system modulates assistance based on pedaling speed, providing more support when needed and reducing assistance when the rider is exerting less effort.
  • Limit Top Speed: The system can restrict the maximum speed of the electric bike, ensuring compliance with local regulations and providing a safer riding experience.



Electric bike cadence sensors play a crucial role in creating a seamless and intuitive riding experience by providing adaptive electric assistance based on the rider’s pedaling input and speed. The choice of cadence sensor depends on factors such as accuracy, cost, and desired performance characteristics.


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