A couple of questions out of curiosity

I’m just curious about two things regarding calibration and tire pressure

I’m guilty of forgetting to keep my tire pressure at the optimal level and have on occasion calibrated my trainer while cold due to lack of patience

So question one… Are there negative effects on riding effort with lower psi?

And, two … If calibration is done cold will it get easier as it warms up? Thermal expansion?


I am no scientist, but here are my thoughts:

If your tires are not regularly reinflated to the correct pressure you may experience tire slippage against the roller, especially at higher power outputs.

And if the trainer is calibrated cold, I would guess that things might get harder as you ride, as the tire would expand a bit and put more pressure on the roller. I’m not at all sure how this would impact the power calculations in Zwift, though.

It may depend on the trainer.
With a Kinetic trainer, performing a spin down before the trainer is warmed up will give you higher power readings as the trainer warms up.
So now you know and if you do it, you are cheating.

Thanks for the answers

I’m not a racer but it’s my goal to improve my distances and times so cheating, even though I’d be cheating myself, is not ideal

I guess the easiest thing to do would be to get into the habit of calibrating after a ride

Depends on where you store the trainer between use and what kind of trainer.
Wheel on needs calibrated each time the tension knob is adjusted.
This should be done after 15 min warm up.

Trainers used indoors are subject to less temperature variation than those in a garage.

Control as many variables as you are aware of and have time for.

No matter what you do, there will be measurement discrepancy.
If you do your best to keep things consistent and are not manipulating factors for gain, then you’re fine.

  1. dont b lazy
  2. always do a calibration on a “warm” trainer

wrong psi + cold trainer = calibration wont be anywhere close to accurate.

if ur just chilling in watopia it’s no problem, but it ur riding any kind of group event then ur setup should be as accurate as poss!