I zero offset before every ride. When I switch on my Garmin it pops up a "Calibrate Power Meter" option, so I tap it. Takes 5-10 seconds.
Originally Posted by
TakingMyTime
As per a previous thread of mine I was getting some weird results from my 4iiii single sided PM. After a recalibration of the 4iiii and Garmin 530 it seemed to resolve itself and I got about 3-4 more trouble free rides in without any problems. Then, 3 days later I noticed that the Garmin was not reporting anything close to what I was doing.
The Garmin in theory should only report the number that is sent to it by the connected powermeter, no alteration of that data. Have you checked for firmware updates for your 4iiii powermeter? I think older firmware versions had some issues with cadence readings, and potentially power reporting because of this. Worth a shot.