Upgraded wheels on my Trainer faster?

Does the marginal improvements in rolling resistance and weight of rim etc. relate to better times on Zwift or am I imagining it?
I have been using Aksium wheels with a Tacx Trainer tyre, but recently upgraded my road bike to a Krysium wheelset UST tubeless. As I couldn’t swap out the tyre for a trainer tyre anymore I just stuck the new wheel on my Tacx Vortex with the tubeless set up to see how it felt. Pretty surprised to find my Alpe PB significantly improved and then Jungle Lap significantly improved also.

Did you re-calibrate the trainer after putting on the new wheels? Unless the bearings were bad on the old wheel, I would not expect new wheels to lead to a significant improvement. Changing wheels can change the interface between the tire and trainer changing the calibration significantly which could be the cause of the significant improvement. For wheel on trainers, you really should calibrate before each ride.

Trainer tyres are generally pretty hard so it could be that your new tyre is griping the trainer better. Run a calibration.

Really? Life’s too short for all that.

I’ve used the Tacx Vortex calibration tool a number of tools and always found it impossible to set. Tool would always claim there was too much friction, but when I adjusted to the point where it was “Correct” I got huge amounts of tyre slip under pressure. Eventually gave up and just set it for what felt right without slippage.

Wheel on trainers can easily show 50-100 watts incorrect,direct driven trainer or powermeters is needed if you want real numbers.