Gears differ BT vs. ANT+

General Discussion
1

When connected with Bluetooth on my Kickr (W10 Dell laptop) I use bigger gears at same revs/speed/power vs. using ANT+ for the connection and I can’t understand why that is or should be? Any thoughts/ideas?
Bill Black

2

There is a difference in how Bluetooth and Ant+ apply the braking force on the trainer. Your power numbers will not be impacted.

3

He asked why there’s a difference and the answer is “because there’s a difference?”

The equations of motion are the same.

4

Well I assume it’s useful to know that it’s not just that specific bike having issues.

I’d never heard of this phenomenon. Anyone else got any info on it?

5

@Daniel. Yes, there are differences …
Ant+ profiles and BT profiles are not guaranteed to be standardized. Amen.
Paolo

6

difference in how Bluetooth and Ant+ apply the braking force on the trainer

Ehmm… now I’m really confused :astonished: Maybe I’m just missing something ???

Are you trying to tell me … for example … the radio tower climb in Watopia would be different (I mean the slope resistance, thus my feeling, thus the necessary gearing, etc … ) if I use BLE and/or I use ANT+ connection? :thinking:

I’ve only used BLE in my 3 years Zwift experience, thus I have no idea how ANT works, but I’d never expected rider’s the experience/feeling could be different …

7

Yes, and that’s why I asked. It makes no sense to me why it should be but with BT (connection works well with 5G now) I use a 53/12 and it results in same power, revs, speed as using 53/16 with ANT+ (connection works well with cable extension/dongle 5G). I know it’s different but no one has yet explained why that is so.

8

The Bluetooth implementation on the Kickr is Wahoo’s own rather than the FTMS industry standard. See here: Wahoo KICKR Tests: Connecting via Legacy ANT+, ANT+ FE-C, and Bluetooth | Zwift Insider

2 Likes
9

Thank you DaveH — that Insider article makes it very clear and specifically references the gearing differential between the Wahoo proprietary BT and the ANT-FEC. Apparently the fix must be applied by Wahoo to the Kickr software if there is to be parity between the connection modes.

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