ERG Mode Résistance delay

Same problem on workouts. Lengthy delays on power ups and power downs. Started a couple of days ago when attempting the FTP Ramp Test. Occurred again today while attempting “4wk FTP Booster Week 2 Day 2 - HIT 45sec #2”. Problem seems to be related to ERG mode. No issues with riding outside of workouts. Very frustrating.

Kickr Core firmware v1.0.12 (latest)
Zwift v1.0.48638
iPad Pro 10.5” MQDT2LL/A
iOS 13.3.1

I’ve also just recently started getting this issue over the past couple of workouts, and seems to be getting increasingly worse. Started off with a few seconds delay between intervals, but increasing to up to a minute. Gets stuck on erg mode and the last power setting even when ending the workout and jumping back into a normal sim free ride. I’m using a windows laptop via bluetooth to Wahoo. Will test again later using iOS. Not sure whether it’s Zwift, the bluetooth connection or the trainer (hoping not the latter). Will also test laptop with ANT+. Definitely frustrating when still pushing 95% ftp 1 min into the recovery interval!

Tested using iOS on iPad and was behaving a lot better, however on a Ramp test this morning no erg shift on first ramp step. Was ok after a manual turn off and on of erg mode. Wouldn’t erg shift back to low watts on cool down though. I was also running a separate garmin so perhaps a bluetooth conflict.

Mismo problema
. Sin solución alguna…

I’ve solved this bug disconnecting my bluetooth AirPods from the macbook.

Could anyone check if the problem occurs unpairing the bluetooth audio device?



I have also experienced this problem; I’ve only just started doing workouts in Zwift.
The first one was fine, but the next two had significant lag. I’ve just done another one but without using my bluetooth headphones and this time there was no lag. Resistance transitions were smooth and at the expected time. This may be a one off but it corroborates with Ruben’s post.



Yet another rider with the same problem in Erg Mode. Using Tacx Flux-S. 40 - 60 second delay in increased resistance. Latest Zwift version and Tacx firmware.

Has there been any response from Zwift? I can’t see any.

Same issue here macosx and tacx flux s, the change of resistance is delayed. Please fix the problem it’s really annoying.


I’ve just noticed this issue for the first time last night - this was my first workout in ERG mode for 2 months (I have been doing a lot of racing with no ERG), and I was unable to hit my wattage targets due to the ERG latency - and during the recovery periods of low wattage I couldn’t get the watts down anywhere near the target. Yes, I got virtually no stars also, and my overall average wattage was way below what it should have been for that workout.

This was annoying. Is this a Zwift problem, or is it a problem with my trainer? I’m using TacxNEO.

Same here new kickr core latest firmware. Win10 fully updated and using companion on iPhone (current iOS).
Performed a spin down
Disconnected and reconnected Bluetooth
It seems like the delay gets longer the more changes there are.

Had the same issue today (Kickr Core with iPad on iOS 14). The delay started at about 15 seconds and then went to over 2 minutes for changes by the end of the workout.

Hi @David_Hopkins_BWCC, I also have a Kickr Core on windows 10, but I use ANT+ FE-C. It works fine for me, used ERG mode last night and on Sunday with no issues. Do you use Bluetooth to connect?

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