How to replace the pedal sensor on your fatbike

By the Sache Bikes workshop · updated 17-10-2026

First, read why the pedal assist is not working: sometimes the problem is the magnet or a brake sensor.

What type of pedal sensor do you have?

  • Sensor at the pedal with a magnet ring behind the crank.
  • Separate sensor under the battery or under the seat, connected with an extension cable (common on the Qmwheel V20).
  • Torque sensor, which also measures how hard you pedal (for example on some 7GO EB models).

Also check the number of pins and the color of the connector. View all pedal sensors.

Replacing the pedal sensor

  1. Remove the battery and remove the crank on the sensor side with a crank puller.
  2. Remove the magnet ring and the old sensor.
  3. Install the new sensor and the ring, paying attention to the indicated direction.
  4. Keep a distance of 2-3 mm between the magnets and the sensor and reinstall the crank.
  5. Connect the plug and test.

Replacing the separate sensor

Disconnect the old sensor and connect the new one in the same place. Also check the extension cable: that is often the real culprit.

Always work with the bike turned off and the battery disconnected. In doubt? Then have the part installed by a bike shop.

Need help choosing?

Send us a photo of the part and the model of your fatbike via WhatsApp: our specialists will help you choose the right part. You will find everything in our fatbike parts. We deliver throughout the Netherlands in 1-3 business days (€ 8.95, free from € 125) or you can pick it up for free in The Hague or Zoetermeer.