KICKR Bike, SIM mode low watts and fluctuation


Has anyone else encountered a problem where watts are generally really low (in double digits) and fluctuate a lot when changing gears, jumping from 60-70 wats to over 200 and declining from there. ERG mode, I can hit the watt target and keep it steady, so I don’t suspect there’s a problem with the power meter itself. Running the latest version of Zwift (1.0 61590) on macOS Big Sub (11.2). Here is short video illustrating the issue you tube. com/watch?v=Nr4UateL-tw

Just thinking out loud… When you just turn on Kickr Bike without connecting it to Zwift, you can pedal and can switch gears, but my recollection is that resistance remains relatively low. Does it feel the same way when you ride in Zwift and your power remains under 80 watts? If this is the case, I wonder if your trainer got correctly connected to Zwift as a controllable. Zwift might be reading the power you generate correctly, but might not be able to send to the trainer a command to increase resistance. Then, you end up riding with no or little resistance and of course cannot generate any significant power.

Just as a thought, it might be worth disconnecting your trainer from Zwift and connecting it back. When connecting KICKR Bike, you should see the same device name in all three Zwift connections windows: power, cadence, and controllable. If you purchased your trainer just recently, it can be confusing - why three different windows if the same device goes into all of them?

Additionally, it may be worth checking through Wahoo app if you are running the latest firmware of Kickr Bike. This is because connecting protocols keep on being developed and changed.

Finally, consider, as a test, switching to a different connecting protocol, i.e., test ANT+ if you have been using Bluetooth, or the other way around. Perhaps something is not working properly with the protocol which you are using.

Hi Andrei, the feeling is quite similar when the bike isn’t connected. This is actually my 3rd Kickr bike, so I’m sure the setup is correct, as I haven’t changed anything with the way I connect to Zwift. The bike is on the latest firmware and the issue is the same with ANT+.

Jaakko, did you say that in ERG mode (i.e., when you ride a workout), resistance is there and you can easily generate a much higher power? What will happen if you turn ERG mode off during a workout, or vary the simulated slope of the level mode (this can be done with a little button on the workout screen in the companion app) - will the resistance remain significant, so that you can generate a good power level?

I am a Zwift user like you and I do not know the answer to your problem, but I think that asking questions along the lines of “what it is and what it is not” may help you to narrow down on the root cause.

Hi, the ERG mode works quite well, but as soon switch it off or do a segment with free ride the problem reappears. I’ve opened a support request with Wahoo, let’s see what they say.

This is the way to go! Wahoo support is excellent. The most important thing is to explain them what exactly the symptoms are, what you checked, how you tried to troubleshoot, what you found. When this issue is resolved, please share with us what was found. It is one of those issues where it is hard to separate the trainer from Zwift.

BTW, if you subscribe to any other cycling app (or can install a trial version), see if you can reproduce the issue with that alternative program - it could be a valuable test if the issue is with Kickr Bike or with the application/computer. As a matter of fact, maybe you can change resistance and measure power using Wahoo Fitness app on your phone? I never tried it, but suspect it may be possible. This could be another good test.

Finally got my 3rd replacement bike set up. It has the exact same issue than the previous bike. Large jumps in watts when changing a gear up and really low resistance when changing down.

youtu. be/ diwNEYsMwcI (not my video) describes this issue perfectly. But according to Wahoo this is normal behavior. I’m really disappointed because these kind of jumps in shifting makes the riding experience feel really unnatural compared to before.

I have a Kickr bike. When i shift up i can feel that i temporary need more power to pedal. This is only minor and the bike corrects itself within a few seconds. The same when i shift down. This feeling is different then when riding on a real bike outside but in no way the same as what you describes.
As it is your 3rd bike replacement i would not expect that this is a buggy one. Maybe the distributor has a bad batch of bikes.

Did you find a solution for this? I just subscribed to zwift and facing more or less same problem. Basically the difference of power is too much between gear shifts around 30-50 watts which is just too much. Does not happen in TrainerRoad resistance mode.

Hi, unfortunately I haven’t found a solution. Wahoo claims that they’re investing, but it’s been months now with no word of progress.