Rotational or power assistance?

Most of our bikes are equipped with a rotation sensor. This registers your pedaling frequency (the number of times your pedals rotate in a given period of time). Above a certain frequency, the motor knows you're pedaling and activates pedal assistance. In practical terms, on our bikes, this means that the motor provides assistance as soon as the crankshaft completes a full revolution.
Some bikes are equipped with a force or torque sensor. This sensor registers the power exerted by the rider on the pedals, and the motor automatically adjusts the assistance accordingly. If you pedal hard and strongly, you'll get plenty of support from the motor. Those who pedal lightly will get less assistance. The pedal-assist sensor is therefore less suitable for older, less mobile people. What's more, a motor with a force sensor is often more expensive than one with a rotation sensor.