Originally Posted by globecanvas

@Edonis13, many power meters will read zero if cadence drops too low. Power = torque x cadence so if the cadence drops low enough that the device is trying to calculate multiple power data points without getting an updated cadence value, the output would be meaningless. Maybe that's what happened on your hill. Depending on how cadence is being calculated, the device may have reported some minimum cadence value, or a doubled value, rather than reporting zero cadence along with zero power.