Power graph - heavy fluctuations

I think this can´t be normal. Any suggestions to solve this problem:

Measured with P2M via ant+ , controlled by Tacx Neo 2.

Are you using erg mode?

No, its a screenshot from a normal race.

Can you switch to having power reported by the trainer?

Sure, I can try it. But thats not the goal because I ride in and outdoors with the same pm to have equal power data.

I realize. But it is relevant to identify the source…

do you know if you have really “wonky” left/right balance?

are you able to record the power on a separate device to see if you get similar readings?

Hi @David_Sc

Welcome to the forum.

check that you have the latest firmware also use the ANT+ FE-c option for power if that is available.

You can put your log file in zwiftalizer.com and see if it is dropouts.


Here the logfile. BTW poor frame rate for a 5700XT :thinking:

ANT+ FE-C is not available

ant+ fe-c is only for trainers, so wouldn’t be there for a separate power meter

A bit of useless trivia for you is that FE-C stands for ‘Fitness Equipment Control’

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I would suggest dropping your resolution, so that your p5 don’t drop below 20fps that maybe the reason you are getting power fluctuations.

Graphics problem is fixed, Zwift was windowed and I switched it to full screen. Now I´m getting stable 50 frames. But the main problem is still there.

Is your cadence constant?

… how about giving your trainer a try as a power source? This will clearly demonstrate whether the issue is with you power meter or not.

Yes, cadence is constant.

Ok, next race will be measured by the Neo. But if the graph looks good it doesn’t necessarily mean that the P2M is broken imho.

Selected the Neo2 as a power source in yesterdays race, the issue still remains. Therefore the P2M has no problem I think.

Yep. Most unlikely the issue is with either the Neo or P2M power reading.

Only possibility I see is the Neo actually generates this fluctuating resistance (or else I will have to assume Zwift is making it do that…) Do you feel anything that correlates with this graph (resistance wise…)?

Any chance you can borrow another smart trainer for testing purposes?

Winter is coming and the problem still remains. Mayve I can borrow a 2T from a friend.