That would explain some of the ZRL and club ladder races I watch on youtube. The odd one you get the rider has stopped pedalling and their watts are still active,… worse part is, some of them stream their rides.
That makes sense… a power offset that’s there nearly all the time. I’ve checked a recent ride where I was using virtual gears. The .fit file shows all zeros for a section where I know I had stopped pedalling down the Epic KOM and there was no evidence of free watts I’m pleased to say, so I don’t think it’s affecting everyone. I’ll do a factory spindown later though to try and make sure things are accurate.
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Yes - that is good. I tried to take a screenshot of a short 4 minute effort - I moved my cursor at as close to the same point as possible to highlight the effect - granted, this is when I wasn’t pedaling.
Hopefully it is visible - I’ve not tried to share screenshots in the forum before.
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From the above - the screenshot on the right is from my Favero Assiomo Duals - you can see both cadence and watts are zero. On the left is Kickr v6 and virtual shifting. In the top portion you can make out the overall effect - and it is more than impactful, we’re talking 2.3 vs. 2.6 w/kg - and this is just a short, zero effort spin. Imagine the impact on larger efforts. I have suspicion that the watt boost is also variable, that’s why I almost tend to characterize it as a % increase to power. While not purely statistically significant in the pure sense - I really believe that I was getting a 10-15% boost overall.
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Yes, that clearly shows what’s happening, and it’s not insignificant, as you say. I wonder why some are/aren’t affected. I often run ERG workouts in a different training app, with no virtual gear pairing, so it’s possible the auto-calibration is working outside of Zwift.
I’m genuinely embarrassed. I feel like crap about it. If I could save rudimentary aspects of my rides to somehow get credit for being active (for Strava and general fitness tracking), I’d try and adjust everything since around September 11th or so - that’s my best estimate for when the issue really started in my case. I received the Zwift ride a couple of days before that, installed the cog v2, and it was likely in one of the Zraces, in which I “tried” to sprint (can’t really sprint too well, due to bad nerve damage in my calves and hamstrings). That’s when I probably triggered the auto calibration in the upper virtual gears 22-24 - something mentioned frequently in the Reddit forum.
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That is also an interesting point. I wish I would have tried a workout and ERG when the issue was happening. I did a couple short workouts with ERG, post-fix, but since I already did the factory spin-down, it went fine. I did some rudimentary testing with using the various virtual gears - sequential vs. Shimano, flat vs. all rounder, messed with using Companion to pair vs. in-game pairing, and also took the trainer in and out of race mode, activating smoothing (the latter two from the Wahoo app) - all this prior to my last resort - the factory spin-down. Testing was very hasty, I was really agitated and frustrated after I realized what was going on, and I just wanted accurate power. I have a Saris H3 and if this issue isn’t resolved relatively soon (with the firmware mentioned above), I’ll probably just revert back to putting my SLR 7 back on the Saris.
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You shouldn’t feel in any way responsible, or guilty. The trainer is meant to be accurate and self-calibrating. But I know how you feel. I want everything to be accurate and a true reflection of my ability, I certainly don’t want to feel I “cheated”. But you are part of the solution for reporting your experience, not the problem!
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Thanks, Dave - I appreciate it.
I was also wondering if I could use it as an excuse to buy a set of Favero Assiomas! Not sure I’d get away with that though 
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Don’t feel like crap,… I see this as a solution to a problem. My wife wants to get the virtual shifting for her Core, but I want her to wait until all this has been settled. Now that Wahoo has been involved hopefully something with happen after all these months of issues.
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I noticed my watts were behaving erratically back in July and found the thread below. I followed the instructions to manually turn off virtual shifting, started doing Wahoo spin downs regularly again, and the problem seemed to go away. I’m going to charge up my power meter pedals to test this out again.
There are definitely multiple threads about this since a little after the start of the year and the introduction of auto calibration and virtual shifting.
Edit: I also did a factory spin down after turning off virtual shifting. For me, it was important to use the manual method to turn off virtual shifting because it would sometimes turn itself back on when I just use the switch in the user interface.
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I’ve had the same issues on the core. I noticed I wasn’t super tucking after getting a zwift click. No PM to verify but I was going 10-15% better than normal.
I hope wahoo add an option to turn off auto calibration.
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They have said they are working on a firmware fix hopefully out soon.
Turning off auto calibration is probably a bad idea people will forget to calibrate and make things worse.
For those tracking this issue, a couple of updates:
- The issue will reoccur, and it doesn’t take very long. Within 2-3 days of the factory spindown, the problem started to happen again.
- The issue (autocalibration) will happen even if you do not use virtual gears 22-24. After the factory spindown, the in-game virtual shifting will feel MUCH different than when the issue is present. For example, when the issue is in “full-swing”, you will be able to use a pretty high sequential virtual gear (ie 21 or 22), and also more or less be able to stay within a gear or two - regardless of the terrain, and regardless of the trainer difficulty setting. Once the issue is in effect, it almost has a similar effect as putting the trainer difficulty very low. I am relatively sure about this. Upon doing the factory spin-down, going back in-game, you definitely will notice that you need to use much different gears - and you won’t be able to simply stay in those higher gears. Immediately after the factory spin-down, I go from using sequential all-rounder gears 19-22 heavily, to gears 11-15 in the exact same sequential all-rounder setting. This is just a data point that helps someone differentiate between when things are accurate and working as intended, versus when the issue has things screwed up.
This information is for people running a setup that cannot easily disable virtual shifting - due to the installation of a zwift cog variant on their respective trainer.
Hopefully this new Wahoo firmware comes out soon.
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Once everyone using virtual shifting gets the firmware update, they’re also gonna want a racing score reset… 
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Yes, if they’re at the bottom of a cat’s boundary and it could move them to top of a lower cat. Or alternatively, if they’re at the top end of a cat boundary, why would they do the firmware update?
It’s a fair point, and there are some people who might prefer the extra boost. At the same time, if I start to think the majority of people fall into that camp, for me - that’s a precursor to an overall negative perspective and before I know it, it might seep into my overall mindset, and I try hard not to do that. I will hope that like others in this thread, most people would much rather have an accurate measurement of their performance and ability, even if it results in getting moved down categories. I’m going to do another factory reset today, since I might try to race. That means I’ll race in category I was moved to as a result of this issue - but I’ll do so with accurate power. I will try as hard as I can, no matter what - but as soon as I come to a kicker of some sort, I’ll be in for an uphill battle - literally, and figuratively.
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Thanks for the additional info, hopefully it will help folks with Cogs and Rides. I can definitely understand the appeal of Zwift Ride and Cog and don’t blame those who purchased those systems, but when I purchased a second core earlier this year I went with the non-cog model because I was wary of having to depend solely on virtual shifting in order to use my trainer.
On the firmware update, I noticed there was no mention of a timeline for this and I know that folks have been in touch with Wahoo about this issue (which they initially said was not an issue) since shortly after virtual shifting was released. So I don’t know whether a fix will be coming all that quickly. In the meantime, if they are not already doing so, I think it would prudent of Wahoo and Zwift too loudly and proactively let people know that this is an issue (beyond this thread) and encourage people to do factory spin downs on a regular basis if they would like to have accurate information and race fairly.
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I couldn’t agree more. There is no question this is a real issue, now validated by Wahoo and Zwift. While I don’t do WTRL or extremely serious races, I do race - and when this issue is present, it results in a very significant advantage. I think I’m ok estimating that I am probably a stronger category C rider - I’d give myself that much. However, I wasn’t just bumped to B as a result of this issue - I went straight to doing really well. This issue is giving those who are experiencing it, about a 10-15% performance benefit. That’s actually crazy. I’m not even sure that professional cyclists who dope get that kind of performance benefit. These are popular trainers, among the most popular, and more than a few people are using virtual shifting.
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