TacX Desktop App - Speed decrease not matching cadence/gear

Why does my speed on the TacX Desktop App slow down when I get to a climb even though I keep a constant cadence and don't change gears? I can see that the power goes up drastically, as expected, but I don't understand why my speed would decrease.

Is there a software setting that I'm missing?

0 eezytiger over 3 years ago

When you use simulation software, with gradients etc your speed in the software is determined by your power, weight, height, surface rolling resistance, bike weight, tyres and wheels etc. Your wheel speed on the indoor bike has nothing to do with it. Otherwise you could climb Ventoux at 20 MPH as easily as you could hold 20 MPH on the flat. It would be nonsense.

0 Ryan.Schreiber over 3 years ago in reply to eezytiger

Yeah, nah. Considering road resistance, frame, bike weight, tyres, wheels, trim colour as constants, because its the same ride, the multiplier here is gradient (plus/minus a fraction)

If I'm on a bike, trainer or real-life, and do consistent cadence on the same ratio/same gear, even with the trainer raising the resistance, the speed would stay the same.

Serious question, which part of the maths am I missing?

0 Alex Masalovich over 3 years ago in reply to Ryan.Schreiber

Ryan.Schreiber said:
Serious question, which part of the maths am I missing?

You missed the inertia of the movement. If your rear hub was without freewheel, then your indignation would be fair.