In the past few weeks, I’ve found that the heart rate reading showing on the Edge was wildly inaccurate early in a ride. In some cases, by 60 beats a minute compared with the rate on my Apple Watch. Often the Garmin rate would be falling, even though I was climbing a hill. What was going on?
I followed the care instructions, wetting the heart rate strap before every ride and washing it regularly. But to no effect.
Finally, the penny dropped. I wasn’t wetting two small rectangular patches on the band. here’s one on the right of the band:
And here’s the other, on the left of this photo (in the middle of the band):
This should have been obvious looking at the diagram on the band:
Once I wetted all four patches, the Edge tracked my heart rate perfectly for every ride. That saved me buying a new strap!