The cadence sensor or PAS (Pedal Assistance System) is a mandatory element in electric bikes in European countries. This sensor enables automatic activation of the motor assistance when pedaling.
The cadence sensor consists of two elements: 2 discs with magnets and 1 sensor with a holder.
It is compatible with the following bottom bracket standards:
- Octalink I,
- Octalink II,
- ISIS,
- with external bearings (Hollowtech cranks)
- Square
The sensor is mounted under the bottom bracket nut. A chainring with magnets is usually installed instead of the smallest sprocket in the crank.
Number of measurement points: 12 and 8
The distance between the sensor and the magnetic disc should be approximately 1-2 mm.