New Firmware Tacx Neo 2 v0.0.38

Changes made from version 0.0.34 to 0.0.36:

  • More silent in lower speeds in Simulation mode

i have no probs with .0.0.34, but want to ask, is Simulation mode used in TR, or is it only relevant for Zwift, Tacx App Riding, is it more or less the road feel thing?

Sim is not used in TR. They use a Resistance step as a percentage of the max trainer resistance , which is not the same as Sim.

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I kind of gave up on my 2T power accuracy and never upgraded to 0.0.36 from 0.0.34
Does anyone know if they addressed power inaccuracy issues? I know they don’t mention it in the patch note but then again, on a 1% accuracy claimed unit, I understand why they wouldn’t.

nothing negative like positive has changed on my Neo 2, the power inaccuray himself i have under control with new TR Powermatch via Vector 3 in TR Win10 App

I raised a support ticket with Garmin/Tacx regarding this as my 2T was consistently reading 4% lower than my OG Neo as compared with my Vector 3 pedals. I supplied them with stacks of evidence including .fit files of the discrepancy. They offered to replace my perfectly functioning pedals!!! :rofl:


LOL. Yeah and Garmin told me 20 watt difference between my pedals and my trainer @ 300 watts is normal due to drivetrain loss. Yeah f*cking right.

I tested out my 4iiii versus Tacx Neo 2T again yesterday with 0.0.36 and no change. Still unacceptably off. $1300 for a trainer only to use my $700 cranks as the power reference. What a sweet deal…

NEO 2 Firmware Update 0.0.38 Available

Improved performance during hard sprints to prevent the trainer locking up

2-5% drive train loss is actually spot and has been demonstrated in several drivetrain efficiency studies.

Garmin is correct, if anything your Tacx Neo 2T is reading a touch high.

20 watt difference while pedaling 300 watts.
Not 2-5%

Try that math again please.

I just read up some studies at it looks like 5% drive train loss is typical.

Taking into account +/-1 accuracy of the 4iii and +/-1 accuracy of the Tacx that brings us to a possible range of 3%-7% difference (assuming 5% drive train loss) or a 9-21 watts difference meaning the Tacx Neo 2T may very well be within spec.

Furthermore, I have a powertap hub, 2x favero dual pedals and a Neo 2T of which I have run my own experiments and have similar numbers.

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Reaaaaaaallly stretching the boundaries of what’s acceptable there.

Also, nothing you said explains the fact that Neo and Neo 2 agree with PM’s like 4iiii, Favero Assioma or Power2Max. While 2T does not.

Thanks. But no. My 2T is way off and for $1400, that is unacceptable and I’d like Garmin to own up and / or fix.

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Spoiler alert, it means your original Neo has always been reading high.

You lose energy through the drive train so a hub based power trainer should in theory always read lower than a pedal or crank based power meter.

Point is 20 watts seems like a lot but after accounting for drive train loss it’s likely just slightly off. ( if off at all)

Is your 4iii dual or single sided?

single. left. i’ve been around the block.

no my neo wasn’t reading high. if you look around enough you’ll realize that it’s not just me either. please don’t keep defending broken products so we can get what we paid for.

You can’t compare a single sided power meter to the Neo which is measuring both legs.

You likely have a power discrepancy between your legs and +/- > 2% is not uncommon.

It’s more than likely your Neo 2T is spot on.

I’ve had
Neo 2
Garmin Vector 2
Garmin Vector 3

They are all in agreement within 1%
Not Neo 2T
Neo 2T is inaccurate.

But keep telling yourself that 2T is perfect :slight_smile:

I never said the 2T was perfect, but I did clearly demonstrate that it’s feasibly within factory spec of +/- 1 % accuracy when you take into account drivetrain loss (5%), possible +/- 2% difference of factory specs and possible L/R leg power imbalances (easily 2+%).

The fact your prior Neo and Neo2 were in 1% agreement with the pedal/crank based power meters means one of them is inaccurate.

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I will stop arguing with you since I have my experiences with multiple power meters and trainers while you have your on paper theories and repeating what I read online a zillion times and already familiar fact of drive train loss which doesn’t explain the power inaccuracy of 2T.

Best of luck. For others who have 2T inaccuracy issues, you are not alone. It is real.

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Sorry, you’re wrong.


The numbers seem to suggest otherwise, at least to any logical person.