[SOLVED] - Trainer reacting spongy (strange power fluctuations)

Resolved Bugs and Issues
#1

Hi

yesterday and today I had a very strange issue.
I was starting my workout and the first interval was working fine. Then the second interval started and the trainer started to act weird. It changed the resistance according to the goal but it also went very low when I had met the wattage. Then again goes up for the required wattage and drops again. This is not like a normal slope, but the resistance changes drastically, from about 160W to less than.10pW and back to 160W.

Closing the app and restarting the trainer didn’t fix the problem. I had to restart my Tablet to make it work again.

One similarity I had yesterday was that I started pedaling before I selected my workout and the warmup started in the background. When I selected the workout I pressed the button to reject the warmup and not to merge the selected workout with the warmup. Could this be an issue?

After the tablet restart I didnt pedal, selected the workout and the trainer reacted normally.

Maybe I can trigger the issue again and record a screen video of the issue the next time it happens.

Regards
Mathias

#2

I have heard of something similar before (usually more like ±10w not huge changes), a couple of times a year someone says something like this but we have never been able to duplicate it or have any idea what it could be. Please let me know if you can. Also strange it should not auto start unless you are on the workout screen we will check this.

#3

For me it was similar with the undulations when I connected the trainer via ANT+. You write that you have a tablet so I guess you have a connection via BLE

#4

So today it happened again

The first interval was working fine and thennthe second one was very spongy. I made a screen video of the issue. Hope this might help @Alex

#5

Thanks for the video. It’s really strange, I can’t imagine what this is. Please let me know if you figure out how to make it repeatable.

#6

Can’t tell for sure what has to be done to reproduce the error.

I leave the tablet on, do other stuff and then start trainerday. Sometimes it works fine, sometimes I have to restart the tablet because the second interval gets spongy

#7

Looks a little bit like the problem I had. Do you connect other devices to the trainer?
I have this problem when I connect my Garmin watch (I record the training to export to Garmin connect) with the trainer BEFORE I connect TD app to the trainer. The first part (low wattage) goes OK, but when the wattage starts to go up it starts to fluctuate.
I think the Garmin watch tries to control the trainer while TD is controlling it or maybe it messes up the connection…
I now always start my training on TD before starting the recording on my watch. No more problems since…

#8

Wow, that is excellent insight. Thanks for sharing.

#9

You should connect your Garmin to the trainer, but not to the “trainer” device, but to the separate BT devices that only transmits speed, power and cadence, so It won’t try to control trainer

#10

I don’t have other devices connected to the trainer.
Tablet connected to trainer and heart rate sensor, thats all.

#11

Yeah, I did this in the past, but since the last FW update of my Zwift hub I can only find it as trainer and no longer as speed/cadence…

#12

In our app it should only show as Trainer but it should still show cadence in our app. We don’t use the speed from trainers but your garmin device likely will.

#13

And you are still having spongy from time to time?

#14

Yeah, no problem in the app, but I can only see it as trainer on my watch… It will no longer see it as the speed/cadence it did before the FW upgrade…

1 Like
#15

So today it happened again to me. The app was in memory all the time and I didn’t close it or removed it from the recent apps.

#16

So previously we tried to update the version of bluetooth library we had and it caused issues. We have been using the old version for about 1-year. Now since so many updates have been done to this library we just updated again. I would think it’s possible this could resolve your issue but it’s a shot in the dark since it’s so random. This should be available today or tomorrow. Let’s keep our fingers crossed.

1 Like
#17

So maybe I have found out how to trigger the issue.

I restarted my tablet
Opened Trainerday
Permitted location
Got to the workout view
Hit the “back” button by accident and returned to the homescreen
Reopened trainerday
Permitted location
Started workout

Second interval was spongy