Wrist HR and cadence lock with latest firmware

I got my new 965 on 2nd Jan, as an upgrade from my old Fenix 5+. I've been using various Garmins with chest strap HRMs for 20 years, and I had hoped that the wrist HRM on the 965 might be reliable for use during running activities (the Fenix WHRM was awful, mainly I think due to its significant weight causing it to bounce about on the wrist).

My first 2 activities with the 965 were an outdoor run and an indoor cycle. I used the WHRM for both of these and was happy with the results.

My 965 then received a firmware update on 4th Jan. Since then, the WHRM has been awful, due to "cadence lock" I believe. I've reverted to using a chest strap again as a result.

For example, during today's indoor cycle (which I recorded on my Edge 840) my chest strap was recording the expected HR of around 150, and each time I glanced at the 965 during the activity it was showing a HR of around 90, which correlated almost precisely to my pedalling cadence. This was quite a surprise as running HR cadence lock stems from relatively forceful footfall transmitting mechanically to the watch on the wrist, whereas pedalling cadence results in a much more subtle mechanical transmission to the wrist.

Has anyone else noticed anything similar, especially in the newest firmware versions?

For reference, I always ensure that the watch strap is very snug before starting an activity, so the relatively lightweight 965 should not be bouncing around on my wrist. 

  • I have FR965 from april 2024 and at the begining it was great and preaty accurate, then with every update become worse and worse... sleep tracking not working, stress level inaccurate, HR monitoring inaccurate, nap detection not working, altitude inaccurate.... and a lot of other problems. They are constantly adding new features and forgot the most important thing, that is ACCURACY.

    Try this... on watch go to settings and make a full backup of watch and settings... then "delete all data and factory reset"... this helped for me....

  • I've found that it helps to restart the watch if it's having issues with heart rate. Especially important after an update.