Tacx neo 2t fw. 0.32 vs. power2max power accuracy

Doing a little test today. My gear is neo2t fw. 0.32, edge1030 and power2max NGeco power meter. Test is an erg mode and small 36 teeth chainring.

Edge 1030 controls trainer (first numbers) and power2max reads power data (second numbers). Heres the results.

300w=314w 250w=261w 200w=209w 150w=155w and 350w=367w bad results. Tested two neo2t units and both have similar results.

Bigger the wattage is difference is also higher.

Heres the data. Laps 2=300w 4=250w 6=200w 8=150w 10=350w

https://www.strava.com/activities/2873992812/analysis/360/421 (better usage)

https://connect.garmin.com/modern/activity/4263262615

Post here your results.

Top Replies

ZIDANRO over 3 years ago in reply to Former Member +1

If you search a little you will find that on a new Dura Ace chain you can have a loss of 4-7 w. So if you consider this and that your PM measures pedal power and Neo 2T at the other end of the chain, then…

All Replies

0 macnuts over 4 years ago

What are the expected results? I mean what is an acceptable power loss reading between crankset (p2m) and rear hub (tacx)?

0 Jone88 over 4 years ago

I don´t know what expected results are but there is some loss between crank and hub.

My old direto still beats this neo in accuracy. Direto is of about 5-7w by whole 150-350w range.

0 Jone88 over 4 years ago

Heres the gplamas elite zumo test (https://www.youtube.com/watch?v=JWh_dSiS-uA). Cheap belt drive trainer, good accuracy against spider based power meter like mine power2max.

Neo2t is much worse than that zumo. Hope we can see new firmware soon.

0 Tofel over 4 years ago

You need to record what the actual output of the Tacx Neo is

0 Jone88 over 4 years ago in reply to Tofel

Heres the actual output by neo and power2max. Same result as above.

Recorded same own created trainer test program. It eliminates overshooting at interval start.

https://www.strava.com/activities/2878871574 edge 1030/ power by p2m

https://www.strava.com/activities/2878723446 edge 1000/power by neo2t

0 Tofel over 4 years ago in reply to Jone88

The expected drivetrain loss is 2-3% of the applied power. Your data is very consistently showing a loss of 4.5%. Moreover, there is no offset in the relation between power and loss (of power). What can you say about the calibration process?

0 Jone88 over 4 years ago in reply to Tofel

What calibration???

0 Tofel over 4 years ago in reply to Jone88

Does the power2max powermeter allow for a zero offset (passive temperature compensation)?

0 Jone88 over 4 years ago in reply to Tofel

You mean that I calibrated p2m to match to neo2t??

0 Tofel over 4 years ago in reply to Jone88

No, I meant the calibration option in your Edge 1030. Unclip from both pedals, bring the left pedal in the 6 o'clock position, find your p2m in the sensor list, tap on Calibrate, and follow the instructions.

There is no need/possibility to do this with the NEO. The option is there, but it has no effect.