Is it possible to perform zero offset calibration without unclipping?
Like coasting or pedaling backwards.
Does this "fix" zero offset issue until the next sprint?
Proper calibration of modern power meters requires you to not put any extra weight on the pedal.
Qq: you test in absolute, which is great, but as you can see, there are a lot of discussion about specific use case. Could you provide your feedback on that? For example I am relatively new to the sport, I have a Magene p515, I don’t think I ever hit 800W, could that be a suitable option. Or on a bike dedicated to zone 2 effort?
It would be plausible only if we were sure anything above exactly 800W triggers the drift, but it could be lower than that. Regardless, it is very easy to get 800W for few spins if you are above 70kg even untrained or not intentional of hitting high power. In that case you may have already drifted away from the calibrated values.
Tracking every high torque power spike and recalibrating each time after that is simply not practical. You may probably use it for indoor training in ERG mode but in this case you already have more accurate measurement from the trainer.
My suggestion to everyone who already own this PM is to check for the drift yourself - maybe Shane has faulty unit (which is unlikely). I personally wouldn't buy it.
