The pedal assist system (PAS) utilizes a magnetic sensor to sense the rotation of the cranks. This signal is then converted to a throttle input to the motor. The PAS has 5 different selectable levels of assist from 20% to 100%. If the PAS is set to level 5 it will provide 100% throttle to the motor when the cranks on the bike are rotated. The actual throttle allows you to provide power regardless of whether or not you are pedaling.