I'm either having a really bad day or my Tacx Neo is suddenly reading low

This morning I went and did my 3x30 SS @90% workout. From the start I was thinking this feels a lot harder than usual, heart rate was rising faster than normally does. Turned the workout down 2%, still feeling hard. I figured I would also turn my garmin on and record power directly off my Assioma Uno.

Surprisingly my pedals were reading roughly 20w over what I was seeing from the trainer. I have NEVER seen it this way before. Usually the Assioma Uno has read a few watts lower than the Neo very consistantly for a couple years now.

Looking at both power files… I can verify the discrepency. The smoothest part of the workout was 23min no backpedal for the 2nd interval. For that 23min the tacx read 294 and the Assioma read 318. I do not use power match, I have NEVER paired the pedals to TR and have always done my FTP tests on the Tacx. Tacx firmware is up to date

Has anyone dealt with this before?

EDIT: Looking at another pair of power profiles where I recorded both devices. I did Bald knob on March 3. Power of both files was 223/224 watts for a 28min segment. Something has definitely changed

I’ve always had this issue with my Neo (gen 1). I just use power match and use my Power2Max PM to drive the actual wattage. Works well enough for me. Not ideal and I’m not happy about it but its been the way pretty much since I got it, and Tacx has never really had a good answer for it.


Were you running zwift at the same time?

Nope, just TR using wahoo TIKR HRM and ANT+ Tacx neo were the only thing paired.

My Neo (Gen 1 / OG) has acted up like this on a few occasions. I’ve never understood why and there’s no logic behind it happening, but I have verified it by double-checking with my Vector 3 pedals. When all is well, they track within 1.5%. When it’s not well, the Neo is 20-30w lower.

After replacing the freehub as well as the internal bearings of the Neo, I am yet to have any issues. But, it’s only been a month or so since I did the replacing.

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Fair enough, I’m just grasping at straws trying to find a reason for my failed workout yesterday.

I updated the firmware on my H3 and now everything seems harder. Guess I need to lower my FTP as my calibration may have been slightly off before. Have you updated your firmware or calibrated after a big gap or weather change?

I was looking at those vids on the support site. Actually taling with support chat now. I have low hopes they will help

Ah, do get back when (if?) you get an answer, please.

Yeah, so he said to leave it unplugged for 60min to reset it.
Then when I asked about the bearings maybe being the cause, I got the canned response that drivetrain loss is expected between pedals and the trainer.

My Neo had a sudden drop off in power and I had similar lack of help from Tacx.

When I opened up the Neo hub I saw that one of the pawl springs had snapped in two. Power was fine once that was replaced. Hopefully that’s your issue, very easy/cheap fix once known (took me some time to get there though)

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I have the exact same issue since a couple of weeks. For years it was perfectly in line with my Quarq so I stoped using PowerMatch. Then suddenly my workouts became crazy hard, switched on PowerMatch and the problem as gone. Later inspection showed a difference of 10 Watts. The difference sometimes disappearance when I ‘re-engage the hub’ by stop/start pedaling.

I will check the pawls.

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Different trainer (a Suito) and it might be as it’s only calculates power, as opposed to actually recording it. It seems to lag 2-3 secs behind my power meter when I up the cadence. I can push into red zone on the power meter but the Suito is still reading below target. About 2secs after things stabilise the Suito catches up. That’s ok on long intervals but less so on short VO2max ones. I usually run power match and it’s not a problem but sometimes I can’t get TR to pick up my Ant+ power meter :thinking:

OK, I have a disc removal tool otw