Speed, cadence, and wheel size

What the sensors measure

A speed sensor counts wheel revolutions. With the correct wheel size, BikeNet turns those revolutions into speed and distance. A cadence sensor counts crank revolutions and reports how quickly you are pedaling in revolutions per minute (rpm). Some devices contain both sensors.

When a wheel sensor is available, BikeNet can use it instead of GPS for smoother live speed and more responsive Auto-pause behavior. GPS remains useful for recording the route.

Set wheel size

1. Open the sensor in Bike Setup.
2. Choose Edit wheel size.
3. Enter the outside diameter of the inflated tire in inches or millimetres.
4. Save and check that the displayed circumference is reasonable.

Improve accuracy

The size printed on a tire is a useful starting point, but the actual rolling size changes with the rim, tire pressure, and rider weight. For the best result, sit on the bike and roll it in a straight line for one full wheel revolution, then measure the distance traveled. That measurement is the circumference. Divide it by π (about 3.1416) if BikeNet asks for a diameter.

After saving the wheel size, spin the wheel and check the speed reading. Rotate the crank as well if the bike has a combined speed-and-cadence sensor.