Tacx Vortex

Just started zwifting on a tacx vortex.

Enjoying it so far apart from a strange issue which is troubling me.

On hills the power measured by the vortex drops rapidly even if I stay in the same gear and ride at the same cadence.

I can be riding easy on the flat ~175w and as i hit a hill the power can drop down to 50w even if it feels like i’m working much harder in the same gear and cadence.

The steeper the hill the lower the power seems to drop. I would expect my road speed to decrease on the hills but not my power?

Increasing my cadence in the same gear makes no difference to displayed power when i’m on a hill but makes a bigger difference to displayed power on the flat?



I have the exact same issue, regardless of what effort I put in up the hill I don’t seem to be able to go over 80-90 watts as soon as I’m on the flat it jumps up to 300 watts.

Any idea what could be causing this?

I think my issue was maybe down to tyre slippage. I calibrated the tyre-roller pressure using the tacx utility app correctly but that didn’t help me.

In the end i bought a trainer tyre and put the roller pressure up-to the top end of the scale and have not had a problem since.