NEO 2 SE power accuracy


I just bought a NEO 2 SE, and compared to my previous trainer, Elite Suio and also to my Stages power meter, it shows higher wattson zwift, than the other 2. E.g., on zwift I can see 320 watts for NEO 2 SE, but for Stages power meter, I hardly reach even 300 watts, 

I will borrow an assioma duo soon, and compare those 2 values too, soon, have you experienced the same?

Thanks for your help,


  • My neo 2t undershoots power about 5%.

    Neo 2t power 285w/ power2max 300w.

    Post your results with assioma here.

    You have good zwift race unit ;-)

  • I've had....

    Neo original - perfect power readings based on perceived effort and heart rate vs power on my second Neo

    Neo 2017 - perfect power readings compared to Assioma Duos

    Neo 2 - 8% low throughout all power levels from 100-1000 W

    Neo 2 - 5% low throughout the power range

    So, despite the claimed 1% accuracy, they appear to be all over the map. The first one was purchased. The remaining three were warranty replacements from Tacx and Garmin.

  • Theres a lot of smart peoples that says something about drivetrain losses etc. ***, facepalm.

    So the older units have no drivetrain losses;-)

    I have tested 2 neo2t units , 5% off against p2max

  • If you watch YouTube videos from DCRainmaker and Shane Miller, where multiple power meters are compared simultaneously, I have yet to see any example where a Neo of any version or year showed any kind of drive train loss - not even 1%. Usually they trade blows +/- 1% against other meters, but there is no evidence that I've seen of systemically lower figures from the Neos.

    5%, never mind 8%, is a heck of a lot of drag, especially from a straight, clean and well lubricated chain line.

  • Hello,

    Completed my first comparision. Favero assioma duo measured 214 Watts for a 1 hour workout, 74 TSS in training peaks. Tacx Neo 2 SE measured 216 Watts, 77 TSS. It is quiet close.

    I will do more,



  • have you tested erg mode?  steady 5min. pull. small chainring , straight chainline.

  • have you tested erg mode? Steady 5min. pull , small chainring, straight chainline.

  • Yes. Today I made a different test. Tacx Neo 2 SE was controlled by Tacx Desktop App, and to Zwift Favero Assioma Duo reported only the power data. Trainer was controlled by Tacx Desktop App. Tacx avg power: 186 Watts, Favero Assioma Duo power 188 watt. I also measured Stages with a polar device, it was much lower, 175 watts. 

    I checked the power curves too, those are pretty close.

  • @jone88 what kind of p2m do you have? (classic, typeS, NGeco, NG?) and with normal round chainrings or with oval? the difference in perfect case is between 1-2% (except on very small sprockets) , if there is more, something is wrong in the setup. there are lots of wrong 2Ts too unfortunately , (lows and highs too, i have a friend who had 2T with almost 20% overrreading! :D) . the orignal Neo1 didnt suffer from such factory calibration issues .

  •  what was you leg balance with Assiomas in summary? if 47-53% , then your Stages is good, just your left leg is weaker (or the saddle is too high, we need to see. Can You do backward reverse pedaling with your heels unclipped  without hip movement but with continous pedal contact? that is a good test for ideal saddle height)