Virtual shifting prevents autocalibration on KICKR Core?

I’ve owned a Wahoo KICR Core for two years now (2022 model). I’ve never had a problem with the calibration of it, it seemed to calibrate automatically as it should. But now, after I enabled virtual shifting (this week), I can no longer reach 0 W (or at least it takes several seconds, and I give up waiting for that). When I stop pedalling, the power hovers between 10 W and 20 W. Sometimes it goes first to 0 for a single second, and then jumps back up.

Here you can see an example from today: ZwiftPower - Login
In case you can’t view that, here are some power values reported after I stop pedalling: 0, 14, 19, 20, 14, 18, 16, 13, 12, and then I give up trying to supertuck…

Of course, I could be just a coincidence that this started immediately when I enabled virtual shifting…
I have a 11-speed cassette, and I’m in 7th or 8th gear, not sure about the number of teeth there but it’s around 15. Latest version of Zwift and the Play controller firmware.

I haven’t tried manual calibration yet.

I don’t think the kickr core had auto-calibration until the recent firmware update.

That said, there was an issue with Mac machines and Kickr Core not getting power which was just resolved yesterday (see this link: KICKR Core reports zero watts [Feb 2024] [1.58] [macOS 11] [SOLVED] - #28)

If you’re on Mac then you might need to update.

The Core has had auto-calibration since 2020…

I’m on Windows, not Mac.

The Kickr Core did not ship with auto-calibration, auto-calibration (described in the article above) is specifically linked from the update notes for the January 2024 firmware release which introduced it to the kickr core.

You can see the release notes for that update here:
KICKR CORE Firmware Release Notes – Wahoo Fitness Support

Here’s a screenshot of the notes:

That release in January 2024 is what introduced both auto-calibration, and virtual shifting.

You can also read about this update on Zwiftinsider here:
Wahoo KICKR Core Firmware Update Delivers Auto Calibration, Virtual Shifting | Zwift Insider

Here’s a screenshot of the relevant section:

Anyhow, not sure what is going on with your Kickr Core, but hopefully someone does.

I’m pretty sure it had auto-calibration before Jan 2024, and you can find some references to that online.
I’ve never had a need to calibrate it manually (maybe done it once a year), and I have a secondary power meter to verify that the the KICKR is reading correctly.
But probably they did do some changes to the auto-calibration in the latest update. I have the latest firmware 1.3.17, so I guess the new auto-calibration isn’t working as well as it should…

This miscalibration is getting racers dq’d on Indievelo, your core needs to be manually calibrated.

Anyone that believes in AUTO CALIBRATION is dreaming for all Wahoo and Zwift HUB trainers.

We have done tests and it just doesn’t work.

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Well that doesn’t sound good. Are the results posted somewhere public?

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On zwift sensor page the setting icon to calibrate kickr core does not appear anymore.

It shows with ANT+ but not BLE.

Nope…i will see if i can post something here.

I have the same now since I got my Kickr Core replaced (sound issues) this week. Thought I move over to BT and made sure to download the latest firmware. No manual calibration available in Zwift. And more it now shows watt less 10 to 20 percent to my Assioma Power Pedals when comparing the files. Not sure what to do…

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Have you tried manual calibration with the wahoo app?

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I performed a manual calibration with the Wahoo app a week ago, and it seemed to help for a while, but today my Kickr was again in need of calibration.

Wahoo has now released a new firmware (v1.4.8) which hopefully fixes this.


I’m facing the same issue.

Had installed the new firmware prior ZWIFT released the virtual gearing. Made calibration etc, looks fine.
Had made a dual recording first race with this firmware:

Then, virtual gearing arrives. My first ride (coast crusher), after first 100m the resistance felt somehow strange for several seconds and afterwards the power was all the time “wobbling” like an added frequency. I’ve got extra Watts too.
After the circle, I’ve stopped, did a factory calibration, and resumed the ride, but after 100m the same happens. I’ve added dual for the last several km.

After that, I did another factory calibration. And the first race with virtual gearing was ok.

Yesterday, I did a ride (sugar cookies) and had the wobble again.

It was really worse as I rode up to the bridge at ~2900s standing with low cadence. The force felt the same at the bike, but the power graph looks crazy.

So, in my feeling the virtual gearing does influence the automatic calibration. And maybe it is road dependend. (Had the issue only at the new routes)

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oh, not seen that. Thank you

Same issue here, even with latest KICKR Core firmware v1.4.8.

Power values are oscillating/fluctuating/wobbling with a regular period of ~5s since I enabled virtual shifting. ERG mode is working fine, i.e. without any oscillations.

A manual spindown through the Wahoo app fixes the issue temporarily, but as soon as the KICKR does an automatic calibration (i.e. when coasting) the wobbling starts again.

I’m not sure whether this is a Zwift issue or a KICKR Core issue. Does anyone know if this behavior has been reported for the Zwift Hub?

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At which route where you riding that shows this issue? I need to doublecheck today my route related guessing :thinking:

This has happened on every route I was riding this week. I don’t think it’s a route related problem.

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I’m having the exact same issue, visible in dual recordings on Zwiftpower. It only happens with virtual shifting on and it only happens for me when standing on climbs, when cadence drops below ~75. (My cadence is usually 85-90 when seated, 65-70 when standing.) Other guys I know see something similar all the time because they always ride with a low cadence. Edit- should add that this is not course specific, and I’m riding on a Kickr Move with the latest firmware, virtual shifting controlled by Zwift Play.

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