Our friends at Wahoo have released firmware updates that fixes some critical bugs. Please see the Wahoo support site for update instructions and the firmware release notes for each model linked below:
UPDATE October 29 - Wahoo has updated their firmware release note pages linked above with this information. Please note the difference between auto-calibration and factory spindown in the context of immediate resolution.
Fixed: Auto-spindown errors when using virtual shifting in specific scenarios.
In the previous firmware versions, there was an issue with the trainer calculating the correct spindown values during the auto calibration process in certain scenarios when also using Zwift Virtual Shifting. The conditions could result in the trainer reporting âghostâ watts (watts while coasting), and could result in a power offset throughout the ride. If you are currently experiencing âghostâ watts, this firmware update will not immediately fix the issue on its own, but having updated to the current firmware, the auto calibration process will fix the power offset over time without manual intervention. If you would like to resolve the power offset immediately , you can complete a factory spindown.
Latest firmware, Kickr Core: I tried coasting during a free ride, and the watts dropped to zero pretty instantly and stayed there untill I started up again. Is there a way to tell whether the auto-calibration has completed successfully, or do you just coast for some time and hope for the best?
I seemed to have resolved the ghost watts, not sure whether that was from the manual spindown or not. My question was generally about the auto spindown. Other than coasting at zero for a short period, is there a way to tell during a ride whether you have triggered the auto spindown, and whether or not it has completed successfully? Do you have to stop pedalling completely, and is there a specific time frame for the calculation to work?
On a separate note, using virtual shifting is still more reliable using the larger chainring, and even then the power reporting appears more volatile compared with manual shifting. But when I stop pedalling it goes to zero almost immediately.
Canât speak with authority for Wahooâs trainers, but on the Zwift Hub, you want to start with a trainer thatâs up to operating temperature, get the flywheel up to a certain minimum speed, then completely stop pedaling and allow that flywheel spin down over X seconds. For the Hub, I believe itâs ~15 seconds of no pedaling.
15 seconds sounds high and would unlikely be possible in any group ride etc. From the Kicr Core page, I saw the following:
"How does it work?
The trainer continuously monitors the motion of the large pulley wheel and flywheel. When the trainer detects coasting, it measures the drag in the system (resistance in the wheels, belt, etc) which allows us to recalibrate. This process only takes a second or two."
But thereâs no mention of any âfeedbackâ during the ride that auto spindown has been triggered and completed successfully. I guess that means we just have to assume itâs operating if you coast for a few seconds from time to time.
For those of us without second power sources or other measurement techniques, after the move from manual to auto, there doesnât seem to be any way of checking that the trainer is maintaining a reasonable calibration over time.
You coast to a stop at the end of every ride. Most riders will stop pedaling as they crest a hill. There are moments in every ride when autocalibration is happening whether youâre thinking about it or not.
You always have the option to do the manual calibration if youâre worried about it.
Many thanks - I completely understand how it is supposed to operate. I just wondered whether there is any way to tell whether an auto spindown has actually been conducted successfully. At the end of a manual spindown, you always get that note that it was or wasnât successfulâŚ
If I assume the auto spindown is working (and for some models the manual version is no longer an option), Iâd have no idea whether or not over time the trainer is drifting out of calibration. I guess thatâs an issue for Wahoo in this case.