Tacx Flux S - Belt driven flywheel clearly faulty

Hi guys,

Hoping I have more success getting a response on here than the Tacx support e-mail.

I'm now on my second Flux S. The first one squeaked like hell and now so does the second. Please see video: https://we.tl/t-Pm6MUk5pPQ

I have wasted countless time e-mailing support, sending back the first trainer, waiting for the second one to arrive and now I am expected to go through the same process for the same model. All during times I actually need to use it.

Looking at the forums hundreds of people have had this issue as well. 

All I have been offered is the same belt driven flywheel model that is obviously faulty. My friend also has the same trainer and the same issue. It has wasted so much of my time and effort. If I can't get a response on here I'll be getting a refund from the supplier and buying a Wahoo. The Tacx support has been absolutely shocking. I can't express how disappointed I have been with this product and the responses from Tacx support so far.

Many thanks,


  • I feel you. You and many others being totally disappointed. Only my good upbringing keeps me from becoming abusive here.

    Tacx + Garmin Support are a big disgrace.

    The Tacx Utility (firmware update) is completely wrecked - not working at all, support is non-responsive and, believe me, my next trainer will NOT be Tacx. I'm so done with this.

    The squeaking noise can somewhat be diminished by opening it up and putting a bit silicone spray on it, that helped me:


  • Same over here - yes, something is fundamentally wrong with the Flux construction (according to my n = 2 study). However, a yearly service routine that involves a lot of screws and a tiny bit of belt spray quietens the trainer nicely. It is now virtually silent.

  • Hi Oliver,

    Since I bought mine on October 6, from the first moment I start pedaling, I notice that knocking noise that occurs in an arithmic way depending on the speed I pedal.

    Although I did not disassemble it because I have an open claim to Garmin Argentina to change the unit for another that does not have that annoying noise level, I suspect that it is the same problem that comes from that belt tension wheel.

    It must be a design and construction issue since it happens to everyone, and there are those who do not give importance to those of us who are somewhat more demanding for the money that one spends on this type of article, which is high, and the perceived value The return is that you practically feel cheated for receiving a mediocre product.

    Another problem that I notice in my case, I do not know if you have tried and it would be good if you could pass me your feedback is that it measures power quite badly in my opinion. I have hit tremendous sprints from 0 to 45km/h in a few seconds, and I hold that speed for another many seconds and the maximum power that I see that it measured is peaks of 350 watts, which seems to me that those values ​​are terrible. Unfortunately I do not have another potentiometer to compare, but I have seen review videos of this Flux S where in accelerations much less violent than the ones I have given it, it marked peaks well above 350 watts. And this worries me much more than the annoying noise it makes, since if it does not serve to measure the power properly, this device is completely useless!

    Well friends, I hope you can give me some feedback about it.

    By the way, I have tried to downgrade to the firmware version that supposedly improves the power measurements, but I did not obtain different values ​​in the sprints that I did.


  • Hello Friend,

    Could you explain better what this service consists of, which screws to tighten and how you lubricate the belt?

    It would be greatly appreciated to have that feedback in the forum since many of us have problems with the purchase of this smart trainer.

    Thanks in advance,

  • Hi Friend,

    Thanks for sharing the link, but unfortunately it no longer works. Could you pass us another one that works?

    On the other hand, I agree 100% that I have made a terrible purchase by going for this Tacx Flux S.

    Not only do I see annoying noise problems that the unit makes, but I also understand that it is not measuring power well, as it gives values far below, and does not detect the high power peaks. Unfortunately I do not have to compare with, other than with Garmin Edge power estimation applications, which I do not know to what extent they are reliable. I do not know if in your case you also experience these power measurement problems which in my case does not exceed 350 watts, and although I am not a Pro tour cyclist, I have some training and should be able to put power peaks much higher than 350 watts.