My Rival watch will not stayed synchronized with my Elements. I’ve tried it with 2 different Roams, and just got an Ace for Christmas and am having the same problem.
I would much prefer using a watch as a heart rate monitor than a chest strap (for convenience more than accuracy). So this has been frustrating me for years. Previously I’ve just recorded my ride with both (so I have routing going on the Element and HR on the Rival) and then just upload the Rival’s data.
But now that I have an Ace with more features (and have a bike with power through ANT) I want to upload its data.
I’ve unsynced and resynced again and again. And actually now my ACE can’t find the Rival as a sensor.