I did another PowerTap versus Zpower comparison. This time it is the full ride without cutting our the first 10 minutes. After about 15 minutes of warming up the KK the power readings do match up better, but even in the beginning they are pretty close.
I just completed an hour of 60% tempo with my PowerTap and surprised myself the power difference was very negligible. Amazing.
What trainer are you riding? If not CT or KickR, then I presume Zwift is not controlling resistance?
I train on my Minoura rollers with a compatible Mag Resistance for tougher sessions. All things being manual, i can only use the gears on my bike to simulate the gradients of ZWIFT island.
I’m on a Cycleops Powerbeam Pro (not resistance controlled by Zwift) and I spin out my 53-11 too easily on the island. I can’t generate the power as a result and can’t effectively compete for sprints/KOM. And I’m not a cyclist!