Zwift run cadence lock

I use a polar H10 as my HRM, a stryd to measure my cadence, and Bluetooth enabled treadmill for speed. In both bluetooth and Ant+ modes, after a while zwift locks on to my cadence as my heart rate.

This does not happen for my cycling workouts when I use the same Hrm with Wahoo kickr.

I use a samsung tablet for my run and ipad for my cycling. ipad had issues with my run.

Thanks for any help or tips.

That is…odd. Cadence lock should only EVER be a thing when using an optical HRM for running; ECG (chest-strap) HR should never be subject to it.

First thing I’d check: if you’re using a sport watch, ensure the system isn’t falling back somehow to using wrist-optical HRM by disabling the optical HR sensor on the watch.

Stop using Bluetooth and switch to only ant+. Also, if you have a Stryd, use it for both speed and cadence…

Thanks. I will also try to turn off stryd and see if the interference is coming from stryd. I prefer to use the treadmill for speed because stryd shows a slightly higher average speed and fluctuates a bit.

The wrist watch optical hrm is not transmitting.

Stryd giving you a faster pace than the TM? Well then your TM needs some correction. Are you running outside with Stryd too? Because that would give you your exact pace. And should be right away correct. Usually Stryd is (must) be slower than the TM as the speed displayed by the TM is the belt speed and not the speed you are running. So it’s physically impossible that you would run faster :wink:
Fluctuation are normal and good and expected, as like on not moving surface, you can’t be exactly every steps identical, your body moves and sometimes your stride length is longer or shorter.

This is here definitely something to check!

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Initially, Stryd used to be slower than my old treadmill. However after using Stryd for some outdoor runs, it seems to have recalibrated. Now it shows, say 12.2 kph, when belt speed is 12.0 koh. I am guessing that this could be either due to minor differences in running style and or TM calibration issues.

I just went for a run without my Stryd. Speed, from TM, and HR, from Polar, was fine during warm up. Then, when I spiked my HR a bit by changing the incline, Zwift lost my HR and attached itself to my “cadence”. The weird part is that I did not have any device that should be transmitting my cadence. Then a few minutes later, HR locked on to a harmonic of the power line, then finally during cool down it locked on back to my Polar. I will try and isolate the issue, if possible. It does seem that a tweak of the software could help and hence I am posting here.

What correct should be is that Stryd would be slower than the TM, because the TM displays the speed of the belt and not the speed of you running on the belt.
The belt always goes faster than you, because it needs to compensate the fact you are on it and slowing it down while running with each steps.

Stryd will measure the speed of your legs moving, so in fact how fast you go, which is not relevant where you run. That’s why a pod will always be better than the TM itself (and then you have better pods than others, etc).

Difficult though to say about what is going on. Bluetooth can be tricky, and probably your Samsung is doing some Bluetooth energy saving. So I guess, your Polar might get disconnected and because Cadence sensor is “empty”, whenever Samsung turns on again the bluetooth, it would go to cadence. No idea. Is your Polar able to measure cadence like the Garmin HRM do? I only know Garmin products… I would say though that you should not leave cadence empty, and eventually try another HR belt too, to see if that would change anything…

Thanks a lot. I will play around a bit to see the fix. What seems to be puzzling me is that I can almost predict that a quick intensity change will lead to cadence lock. I agree with the Stryd logic. Perhaps I should run with it outside more often. Thanks again.

You’re welcome! Give an update when you can :slight_smile:

I have played around and the issue still persists on some runs. I am now using zwift on a laptop running windows to see if it was a OS specific issue. The runs start out fine with hrm and cadence showing correct values. At some point, I need to adjust my HRM belt as it starts slipping off. It is around this point that zwift locks on to cadence. After this, cadence lovk becomes a big issue, reverting back and forth between true bpm and cadence. Therefore, it seems that when zwift is getting faulty signals it is looking around and locks on to a different signal.

Are you also using an ant+ dongle ?

Ensure that your HRM is really tight, it should not slip away. I have used Stryd for speed and cadence with a HRM Pro for 2 years without encountering any issues, that should be the case every time…