I switched from the Flow to the Vortex Smart 2180.
I use an old Cannondale 26" MTB with a Schwalbe training tyre with 1.995mm circumference.
When calibrating, I have to go all the way towards loose with the screw. And I end up just to the left of "too tight". Nevertheless, the tyre slips on every climb.
When riding in the desktop app, I see relatively similar watts compared to my power meter on the real bike but it feels heavier. I ride at about 2 - 2.5 watts per kg of body weight. However, I am constantly and easily overtaken by other bikers for whom values in the range of 1.5 - 2 W/kg are displayed. My speed in the app is also about 25-30% lower than what I achieve in reality with the same gear ratio.
Is it possible that the Vortex cannot work with a wheel circumference of less than 2,000mm?
What else can I do to get a fair performance displayed?