Garmin CAPTEUR DE CADENCE 2 (Reese's Law)

The Garmin Bike Cadence Sensor 2 attaches to your crank arm with rubber bands — no magnets, no special tools, no permanent modification to your bike. It measures cadence (pedal revolutions per minute) in real time, giving you a reliable metric to pace your effort and train more consistently, whether you commute or ride for sport.

Thanks to dual ANT+ and Bluetooth Low Energy connectivity, the sensor can broadcast to multiple devices at once: a Garmin head unit, your smartphone, and apps like Zwift or Garmin Connect simultaneously. Up to 2 Bluetooth devices can be paired at the same time, with unlimited ANT+ connections.

Battery life runs to approximately 12 months based on one hour of use per day, so it simply stays on your bike and works. When the time does come to replace it, a standard CR2032 battery from any pharmacy or supermarket does the job in seconds. The IPX7 rating means accidental immersion up to 1 metre for 30 minutes won't cause any damage.