tacx neo problem with wattage

I have bought a new tacx neo … For this there was a tacx ironman … Now what immediately strikes me is that my ftp has dropped by 50 to 60 watts …

Do other tacx neo users also have this?

Or is this a problem of tacx or does this have to do with updates of zwift or tacx?


I would guess the your old trainer was reporting 50-60 watts too high. What was your FTP with your old trainer and what it’s it with the Neo? Did your old trainer broadcast watts or was Zwift estimating watts based on rear wheel speed (zPower)?

FTP 350with tacx ironman genius … wheel base power …
Is that such a difference?

I went Vortex to Neo.  One is 3% accurate the other 1%. 

I didn’t have a massive jump of FTP but having used both pretty consistently I’m quite confident my performance was overrated by the Vortex.  Too many variables such as tyre tension etc. to make the FTP innacurate.  

I not sure how the Neo would under report your FTP.  There’s very little to affect the data it offers.  

I was lucky as in between Vortex and Neo I had a back operation so couldn’t ride for a while, I used that as the reason why my FTP dropped.  Makes me feel better about myself rather than admitting I wasn’t as good as the Vortex said I was.

You’re getting the reality check that users of Tacx wheel on trainers often get when they upgrade to an accurate trainer like the Neo or a power meter. You’ve just got to take it on the chin.

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Hmm, I dropped 25watts when I swapped from using the quarq powermeter to the Neo.  What’s interesting is that I have another quarq that I use on my new road bike, and that matched the first quarq too.  So I’ve 2 chainset powermeters that agree and then the neo that is a touch on the low side.  More than that, I found that I was relatively quicker on the climbs in zwift and slower on descents and on the flat in zwift when using the neo as the source than the powermeter.  

Having said that I’m on the firmware from mid 2017 and not the December version as I saw there were some issues at one point and being able to train consistently was more important than winning C-cat Zwift races.

I too am experiencing a 30 watt drop from my Tacx Neo on Zwift and my new Quarq Dzero power meter.  That explains why I don’t feel any drifting in Zwift and can’t keep up with group rides! I’m putting in the effort but not getting credit for it from Zwift.

The thing is, how do you know which one is accurate? What if the Neo is accurate but the quarqs are over recording?

Google searches have reported 25-30 watts under reporting for the Neo against a number of power meters including the Quarq which has been reviewed as being accurate. It matches my experience on the road and explains my low performance on Zwift.