Have just purchased a second hand Tacx flow to use for zwift.
Having put my bike on the trainer, I noticed I had very low wattage numbers for the effort I was putting in. For example, getting to 100 watts took all my energy. I also attempted to do the calibration process on the trainer, and despite it starting with it asking me to reach 30kmph, I couldn’t manage to get past 20 at max effort.
two possible problems are I have a 700x38c tyre and also that when I place the back wheel on the trainer, it doesn’t sit in exactly the centre; it sits slightly to the side but is still firmly against the roller.