This is a common issue new Vortex Smart owners encounter–I know I did! I thought I had done everything correctly–I unpacked my Vortex, plugged it in, updated the firmware, calibrated it, then fired up Zwift and paired it up. But when I started riding the hill of Watopia I found myself thinking, “Is the resistance not changing, or am I just in really good shape?”
The solutions to this issue are usually simple:
Solution 1: Update Firmware
If you don’t have at least firmware version 3.1.7 installed on the trainer Zwift will be unable to change resistance on hills.
Solution 2: Disconnect Bluetooth
Zwift cannot control your Vortex’s resistance via ANT+ if you are connected to it via Bluetooth. Strange but true. So while you need to connect to the Vortex via Bluetooth to calibrate it, you’ll need to disconnect it from your phone’s Bluetooth in order for it to respond to inclines properly in Zwift.
UPDATE: thanks to the June 2nd Zwift update you may also control your Vortex entirely using Bluetooth via the Zwift Companion app.
Solution 3: Pair as Controllable Trainer
Make sure you pair your trainer as a “Controllable Trainer” (bottom-right of pairing screen) AND as a power meter (top-left of pairing screen). You need to do both for it to function properly.