My hrm has gone off the deep end. After wussing out on 5 mile pass yesterday I went for a ride. I spent over half of the ride in zone5 at about 180 or so BPM. At least that is what it is showing. Knowing this was incorrect because some of the highest rates were coasting down hill and even doing some easy pedaling it would not go down I went home and borrowed Susan's chest strap and now it works fine. Guess I will have to buy a new chest strap. Check out the graph. If only I had the heart and legs to run like this.