Tacx flux S doing bad with new Wahoo App

Hi guys,
Since SUF upgraded to “Wahoo system” App I have really annoying bugs:

  • If training isn’t pre-download before I want to do it, its -always- got stuck (video, audio)
  • ERG mode isn’t working properly whenever watts are getting higher

I’m using IPad with OS version 14.7.1, the issue is repeated also with another IPad / MacOS.
Also, I must say that before updating everything works FINE.


@yardench1 The iOS version you are using came out in July 2021. The current version is 15.3. Try updating to the latest version. You can also try logging in and out of the app and deleting and reinstalling the app. Also check that your Tacx Flux is also up to date with the latest firmware.

Connect to the Tacx with ANT+ rather than uetooth for now as well.

Can you use ANT+ from an iPad?

No idea, I’m an Android & Windows user. The issue is with the Bluetooth protocol the Tacx uses (and I suspect a fix is coming) You might be able to use ant+ with a separate dongle though like I do with my Windows PC. @Glen.Coutts do you know?

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No, iOS (iPadOS) does not support ANT+.


@DameLisa, what @RServranckx said. In the before times there used to be a dongle that Wahoo made but not anymore.


iOS does not support any non-native protocols. ANT+ is just one of them (ask Kurt Kinetic about this, their old Gen1 inRides no longer function on iOS).

OK good to know. Hopefully the fix arrives soon :pray:t3:

I’ve updated to the latest version (15.3) and still, ERG mode is doing trouble.
I must say again, that in SUF app, everything works fine.

Also, I have the latest firmware of Tacx Flux.
To be honest, it’s really frustrating to train like that (always on level mode), and it’s not the nicest to pay for an App that does not give you all the actual features (and ERG is one of the most important of them).

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Do you have the latest version of SYSTM on your iPad/Mac? Current release is 7.18 and the release notes say that an issue with Tacx bluetooth was resolved in that release.

If you do, and it’s still not working this might be a long shot but worth a try.
I’m not on a Tacx Flux S but in the past (including before SYSTM) I would sometimes have trouble getting ERG to work properly during workouts and I would often get it to resolve by doing a couple things.

  1. Toggling trainer control off then back on at the start of the workout.
  2. Making sure that no other apps/devices were trying to steal the Bluetooth connection (so, I’d turn bluetooth off on my phone or computer). So, be double sure I didn’t have another open app that may be trying to connect to the trainer (in my case it would have been the Wahoo Fitness app or Garmin Connect (where I would go to get firmware updates etc) and in yours may be a Garmin Connect or Tacx app.
  1. Sometimes I would also turn Bluetooth itself off, then back on, on the device I was using (in my case, usually my Mac, but sometimes an iPhone).

If none of this works make sure you’ve reported the issue to the minions if you haven’t already:

Also, as for streaming vs downloading, I would always download first. Even back in the SUF days. It never took more than a few minutes to do and would provide me with the piece of mind of knowing I wouldn’t have any buffering issues. With the app now allowing you to view what has been downloaded, you can always delete it at any point after the ride if space is an issue at all.

Hope it gets sorted for you soon!


Same thing happening to me , & I’m using Mac M1…ERG not working …& horrible noises …I was 1 year with Zwift never have a problem…& wahoo support really sucks big time…

@Yitzhak1411 How often do you check the wear on your chain and cassette and do you regularly clean and lubricate those parts? It seems strange that just a change in software - from Zwift to SYSTM - would create a noise. If you can be more specific about what the problem is maybe we can give you some ideas on how to solve it.

As strange as it maybe its the truth …yes I’m old , but I do what the bike store told to do ,time time wipe it , & spray W40 on it … Why should I be touching the cassette …& if they shitty support after getting a video ,told (if ever they get back to me ) that the kickr needs service , I’ll take to my bike store to try to fix …look I’m simple retired old guy …not paid by Zwift …like most people here in this form paid WS lobbyist …unfortunately a shitty system is a shitty system no matter how many mouthpieces Wahoo paid

Spray WD40 on what?
You really don’t want WD40 on or near much of anything to do with either a bike or trainer.

Also, and please take this as gentle advice, consider your tone. Saying that anyone in here who is positive about the platform this whole forum is about is “a paid mouthpiece” is not likely to garner you much help.

As indicated by @JSampson also, it is also highly unlikely that a change of software would cause a noise in the trainer. It is possible, yes, because the software controls the resistance, but it is unlikely.

Because they require maintenance, even if used indoors.
They do not require WD40. The cassette and chain will require light cleaning (provided it’s only used inside) and lubrication, though. Less regularly than a bike that is used outdoors, but refreshing the chain lubrication is still a requirement, as is eventually changing the chain and then after a few iterations the cassette also as they are prone to wear. They will last longer than they would do outside, but you’ve still got metal rubbing on metal, rubbing on metal.


Plenty of trainers also end up with a stretched belt that slips and makes a super awful screeching noise. Most trainers need regular servicing too. Just like any powered items with moving parts. The Flux belt sometimes slips and gets noisy if the tensioning needs adjusting. That’s a Tacx issue, not a Wahoo one


@Jon Said:

Blockquote Spray WD40 on what ?
I will tell you that doing this will INCREASE wear significantly if that is all you are doing. WD40 is THE best degreaser known to any mechanic. You want to use cleaner, you found it. If you want a lubricant, you want to look at something else. My guess is your mechanic wants to sell you lots of chains because that is what will happen. The chain will dry out and wear through quickly. BTW, I have over 35 years of working on and with bicycles. I’m not a mechanic but I play one on TV.
As to the sudden noise on your trainer, it could be any of a number of things. First, does it make this noise on Z? If not, is it engaging ERG mode and IS IT WORKING? You might find that it isn’t. Second, are you using the exact same protocol? Z might be using BTLE (FTMS is another name for it) and SYSTM is using ANT+. Different mechanisms are used for the different protocols on most trainers to get ERG working.
BTW, I don’t work for Wahoo. I don’t work for anybody. I’m retired…