The zero offset of the power meter is essentially the sensor reading or values measured when the power meter has no pedaling load (torque) applied. The torque applied to the securing hardware can impart some strain into the crank material that is easily accounted for by performing a zero reset on the power meter. Any time the power meter is removed from the bike and reinstalled, a zero reset should also be performed. Ambient temperature shifts can also affect the zero reset to some extent.
