I am using an Elite Novo Force connected via Garmin cadence, speed and heart rate sensors and an ANT+ USB dongle. I realise that the virtual power curve estimate is unlikely to be 100% accurate, but until now it has at least been consistent over 5 months of fairly regular use and I have been happy with the set up.
On my last two rides this has completely changed. On the second ride I decided to check the apparent discrepancy with an FTP test - the results suggest my FTP has increased by around 100 in the space of about a week - clearly this is unlikely to be a real gain.
The problem is I cannot identify any change in my set up. I have checked and rechecked tyre pressure, wheel-on roller tightness and the resistance setting (set to 3 as stipulated by Zwift). I believe my sensors are functioning correctly - certainly the increased noise at HR threshold suggests the wheelspeed has increased significantly.
I have contacted Elite to see if they have ever had any problems with inconsistent resistance in this trainer.
Does anyone have any suggestions for other variables to check? Has this issue ever arisen previously? I would like to at least understand the problem before I cough up for a new, smarter, trainer.