Zwift supports calibration for certain trainers over the ANT+ FE-C and native Bluetooth Low-Energy 4.0 (BLE) protocols so that you can get the most accurate performance for your trainer before starting your ride. This functionality is not available over the older ANT+ protocol or bridged Bluetooth connections (Zwift Mobile Link app).
Note that the calibration feature may take one or two runs before the capabilities of your trainer are properly detected by Zwift; and until then, the button on the pairing screen may not be visible.
Here's a table of the trainers that are currently supported, and over which protocols:
|Trainer Name||ANT+ FE-C||BLE|
|Wahoo KICKR 2016||Y||Y|
|Wahoo KICKR SNAP||Y||Y|
Note that the older ANT+ protocol may show up for some of these trainers, and the calibration function will not work unless you pair over ANT+ FE-C, so be sure to select the FE-C pairing option.
If the calibration option is available for your trainer, you'll see a wrench next to the "Unpair" button on the pairing screen after you've connected your trainer. Click it to open the Calibrate Spindown window.
Once you've read the instructions, select Next.
Accelerate to the appropriate speed...
...and stop pedaling until the flywheel stops spinning.
Congratulations! You'll be taken back to the pairing screen, and then you can start your ride.