If you perform the auto-zero then you know that the conditions were perfect- no force being applied to the pedals and so on.
If the Garmin decides to do it when it feels like it then you could be soft-pedalling rather than coasting- and therefore the zero-offset would be wrong, and FUBAR your whole power file- just as was happening to me with mine.
If you perform the auto-zero then you know that the conditions were perfect- no force being applied to the pedals and so on.
If the Garmin decides to do it when it feels like it then you could be soft-pedalling rather than coasting- and therefore the zero-offset would be wrong, and FUBAR your whole power file- just as was happening to me with mine.