Zwift Hub Low Watts After Calibration


I just recently ran into this issue and am wondering if there is a fix for it. I was free riding for about 45 minutes or so while I decided to calibrate my Zwift Hub and after doing the calibration. My watts went down to be outputting 80 watts or so from 130 watts or so. I weight 160 lbs so me barely outputting 1 watt per kilo does not seem accurate. I don’t know if its due to me calibrating the Zwift Hub while it was too warm or if this is just my actual output. Even if I try to sprint, I cannot get to 200 watts where as before me calibrating I was able to do so. Also my last calibration was 02/10/23. So far every time I calibrated I was getting similar watts. This is the first time where it dropped very low to where it does not align with any of my previous rides. Please if anyone can help it would be much appreciated. Also both Ant+ and Bluetooth were giving me low power numbers after calibration. If any other info is needed, please let me know! Thank you!

Trainer: Zwift Hub
Last Calibration: 02/10/23
Version: 3.9
I used Zwift on a Windows 10 PC on bluetooth but I also have Ant+

I have a similar issue with my Zwift Hub! My watts dropped significantly after the required calibration. Have you received any response from Zwift?

Are you using 3.9 or the new 4.01, @Ambrozy_Kozikowski?

I did find a couple of manual calibrations with 3.9 led to some wacky watts after. Would calibrate and then have to do crazy cadence to just get it to register say 50 watts. I found that if I did it a second time that seemed to resolve it. Since I went to 4.01 and haven’t manually done that, I haven’t had any issues with things like that.

I’m having this same issue. The first calibration we did made the bike impossibly hard to ride, with wildly low watts. A second calibration made it a bit better but my watts are still 2/3 what they previously were.

Can you tell me how fast you spin up when calibrating your bike? Zwift doesn’t give any guidance there and I’m wondering if the gear you’re in or how fast you spin up effects the calibration.

For 4.01. I warm up for five-ten minutes. You then just stop peddling. I usually do that for about ten seconds - it should auto-calibrate during that time.

Thanks, I’ll give it a go…