ERG Mode Time Stretch

On a few workouts lately time has begun to run slower for my trainer’s ERG mode than it does for the rest of the world. Hard to explain in words but this photo of Mokelumne +1 is really clear.

Made my profile public so maybe you can see the workout file here too? Log In to TrainerRoad

No ERG change at the first sprint so I used the gears to try to outrun the trainer and do the sprint anyway, then the trainer surprised me by delivering the missing sprint about 4 minutes later. I expected it the second time so didn’t attempt the sprint when it was meant to happen, but this time the delay was even longer - 8ish minutes, so roughly double. You’ll see it never got to the cooldown at the end either even though I was changing pedaling technique and even adjusting workout intensity to figure out what was going on.

I figured it was signal interference from a head unit I’ve been using to dual record (am preparing to switch from LH power meter to Assioma Duos, so the workouts are all still running from my 4iiii crank arm but I’m passively recording the assiomas on an old Wahoo bolt for comparison). I’ve just checked though and that head unit isn’t paired to the trainer - it doesn’t even know my Kickr exists.

TR desktop app on an iMac, Wahoo Kickr '18, powermatched to a 4iiii LH crank arm.

It wasn’t happening every ride and only affected endurance workouts for a while so I didn’t worry too much about it. However, it crept into a set of 30/30s last week and finally impacted on the quality of a more serious session. I switched off the head unit as soon as I noticed it happening, closed all the apps on my phone, and then put it in airplane mode with bluetooth switched off just to be safe. I stopped and rewound the workout by one interval hoping this would force the TR desktop app and the Kickr to reset their time sync, but the problem continued to the end of the workout anyway. Log In to TrainerRoad

Any idea what might be causing this or how to stop it? It’s especially confusing now that I’ve realised the Bolt isn’t paired to the trainer. Happy to accept it might be interference from my phone (either TR app or Wahoo app) but then I would expect timing to re-set after putting it in airplane mode and rewinding the workout a bit.

I had this problem too, also on a Mac, and it was ultimately solved by support. The problem was introduced by a software update, and they fixed it by changing a setting in the backend.

(edited for clarity)

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Thanks @philclayton. @ZackeryWeimer shall I just copy/paste this into a support ticket or will you need more info?

I’ve had that issue a while ago, and think it was caused by connection dropouts between my phone and the trainer. Think TR support can see if there are dropouts, so talking to them sounds like the right move to me

Have had the same issue and was able to mostly solve it so far by buying the tacx ant receiver and completely deleting and reinstalling TR software. Was also on Mac with saris H3.

Hey there! Sorry to see you’re running into some ERG mode woes here.

I dug into the support ticket we had open recently with @philclayton (thanks for your comment – very useful in helping us troubleshoot this!) and toggled a couple of backend settings we changed with their account as well. In Phil’s case, it looked like those changes did the trick, so we’re hopeful that it will help you as well!

Keep us posted on your next workout so we can see if switching those settings on the backend work in your case too.

It sounds like you’re on the right track with turning off/disconnecting other devices that may be causing interference with your trainer, but here are a few more tips we have that may also help:

  • Calibrate your KICKR every 2 weeks or after transporting your KICKR to a new location.

  • Check your KICKR’s firmware and update if needed.

  • Unplug your KICKR for 5-10 minutes to give the unit a “hard reset” (ideally, we’ll leave the trainer unplugged between every session to allow any bad data to be “cleared out”).

  • Check your computer’s/phone’s Bluetooth settings page to ensure your devices are not connecting to your computer/phone itself rather than the TR app.

I think this should be a good starting point – you can find more info on Bluetooth troubleshooting and ERG mode troubleshooting in the following articles:

Hope this helps! Feel free to let me know if you have any other questions and please do let us know if your troubles continue.

am i understanding that you have a specific setting in the TR software for users that have this trouble?

Thanks @ZackeryWeimer. No issues with an anaerobic workout today but this was always an intermittent issue. I’ll come back here to check in again in a couple weeks unless the problem crops up again sooner.


We don’t have a specific setting – rather, as we work to improve TR, we release backend updates that generally improve how TR functions. Sometimes as we roll out these updates, we’ll find bugs that impact a small number of athletes.

We report these bugs so our devs can fix them, and in the meantime, we’ll switch off the backend setting that may be affecting an athlete.

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Haha. I clicked in thinking “I’m interested to see where this is going”, because time DEFINITELY stretches for me on the trainer!


Haha I nearly opened with some kind of tongue in cheek acknowledgment that I wasn’t actually posting about how just how long 5 seconds feels during a 4 minute VO2 interval! :joy:

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2 interval sessions under my belt since the settings adjustment. Does one of those backend settings have something to do with pre-empting the lag between the start of an interval and ERG actually adjusting the resistance? I know TR engineers have done some clever work to ensure better real-time ERG responsiveness compared to competitors.

The overall time sync throughout the whole workout seems better, but it feels like there’s now a fairly noticeable delay between the start of an interval and ERG responding to it (a bit like doing ERG workouts on other platforms or on TR 3-5 years ago).

I’d rather have this issue than the previous one, particularly since I know the lag usually carries for the same duration at the end of the interval so the overall workout is the same, but it’s a little bit disappointing.