Cadence linked to speed in ERG mode?

(Stuart Thomson) #1

did one of the 10 week FTP builder work outs last night. All worked well but i noticed that despite the cadence sensor showing it was paired it was not correlated to my actual cadence. Rather it was showing a cadence relative to my speed. So at constant power  (as set by ERG) if I went up a hill, cadence fell to 50 if I went down a hill cadence went up to 100. All the time my actually cadence was the same (around 80 i would estimate). 

I messed around a bit slowing my cadence way down, and then speeding it up and given I was putting out the same power (ERG managed) and therefore was at a constant speed (on the flats) i should have seen a cadence change but didn’t 

The good news is that the Kickr was adjusting resistance to my change in cadence to get to a constant power but it just mean the cadence reading on the screen was completely useless for training purpose. 

(Steven D) #2

Hi Stuart,

It looks like you already have an open support ticket for this issue and my colleague Gary is actively working it with you. 

It seems to possibly be an issue where you’ve got multiple different devices you’re using to measure cadence.

Seems like the best solution is the use your stand-alone cadence sensor. The internal cadence sensor on your KICKR will use an estimated cadence, which is not quite as accurate. Make sure you’re pairing your cadence sensor directly to the Apple TVs native (built-in) BLE connection, and pair your HRM with the Zwift Companion. 

Assuming you’re always using a stand-alone cadence sensor, please check that the battery isn’t old and replace it if necessary. Also check and eliminate any possible BLE interference sources that could be messing up your cadence readings. 

Gary should have your issue under review on the ticket.


(David Taylor) #3



I am new to Zwift and using a Kinetic Smart Control trainer.

I have read about ERG mode and seem to understand it (when in workout mode with a 100 watt section the trainer will provide 100 watts with my given cadence and if I maintain that exact cadence when I hit a different wattage section the trainer will adjust and I will be producing the requested wattage for that section).

I too experience my virtual cadence (and speed) dropping off based on climb gradient and just assumed it was a simulator function that was displaying a realistic climb so I didn’t look like a Cat 5 racer when I am a recreational cyclist while in ERG mode.

Is this not the case?




(Stuart Thomson) #4

I think it was a case of the cadence sensor showing as paired but not actually pairing properly due to too many connections.

I’m not sure where the comment about multiple cadence devices comes from. That is misplaced I only have one and my Kickr doesnt broadcast cadence.

The BLE connections with the Apple TV are just a bit buggy. I often have to repair mid ride.

But the key here is that the Apple TV cannot pair the smart trainer + cadence + HR. One of these will have to get paired with the companion app. The app then I believe uses your wireless network to share the input with the Apple TV and display on the TV

I never got an answer as to why my cadence was varying with speed but I suspect it is some kind of default backup estimation where perhaps there was at some point a cadence reading and it dropped.

So if anyone else gets this it’s because your cadence sensor isn’t paired properly even if the app might show that it is.

David in your case I suspect it is probably a simulator function if you are not running a seperate cadence sensor. I’m no familiar with your trainer though. Obviously it makes sense that your speed should decline at the same power once you start going up a hill though.

(David Taylor) #5

Thanks for responding so fast Stuart.


(Stuart Thomson) #6

No probs mate. I’m new to this too by the way :slight_smile: all a learning process.