Since the tacx vortex can simulate a climb of up to 7%, how does the application calculate users speed and power when the climb is above 8%. Is it using zpower at this point?
Power is still being collected via the strain sensor at the resistance unit on the roller.
From this power is still plugged into zwift’s algorithm, to get speed.
As for resistance, tacx only tops out at 7% full scale for a rider that is about 75kg. So grade is only accurately felt up to inclines of 7% after that it just uses 7% sim grade.
You are still using power as the trainer provides power number to zwift, your just not feeling the full terrain.