Kickr 18 resistance different between Ant and BT

General Discussion
#1

I’ve noticed for a while now that the resistance on my kickr 18 doesn’t feel right (I have done numerous calibrations). I run Zwift on 100% trainer difficulty, but I don’t need to use the small ring up hills and I’m not producing big Watts.

When I switched to Bluetooth I noticed a big difference in resistance meaning I did need to use the small ring to climb.

However I’ve changed my setup and no longer can use BT but want to see if anyone else has noticed this?

A side question is why do I get 2 options when pairing equipment? I choose the FEC as the other has major dropouts. Just curious.

Thanks

#2

If you’re running 100% and don’t need the small ring up hills w/ANT+ but do w/BLE, then you def have a problem.

When pairing via ANT+ use the ANT+ FE-C option. Also make sure your Kickr firmware is up to date.

#3

More over, when you’re pairing over ANT+ FE-C, do you usually disable the Bluetooth through the Operating System Bluetooth settings on your device running Zwift? While Bluetooth and ANT+ should be able to co-mingle, but my personal experience working with the two protocols is that they can easily affect each other.

#4

I’ve noticed that resistance is less if I connect with Bluetooth than Ant+ dongle . On a flat section I happily push a 50 x12 gear @ 64/65rpm on bluetooth … using Ant+ the best I can do is 50 x 14 rpm at 60rpm …
I’ve calibrated the Kickr for both and it’s made no difference…

#5

Same issue here…

#6

Some background here. (Ant+ FEC should have a higher baseline resistance than Bluetooth) https://zwiftinsider.com/wahoo-kickr-tests-connecting-via-legacy-ant-ant-fe-c-and-bluetooth-ftms/

#7

I had an answer from Zwift … when I connect with Bluetooth it doesn’t recognise the power meter on the Wahoo trainer so gives little resistance… The ant+ dongle does see the power meter and so adds resistance… that’s why there’s a difference…

Jonathan…

#8

I’m on an original kickr and used an aging PC and connected over ant+ for a few years. Recently I switched to Apple tv and Bluetooth (connecting via companion app) and find the resistance much lower in the same gear. It can be a problem on the flat as using a compact chainset I often run out of gears on a sprint finish.