My goal is long distance biking at moderate speed. I used HRM to get to a sustainable speed of 17 MPH. That done, my limitations are legs and nutrition issues and NOT HR. My HR stays below 125. I push my limits on occasions and feel my HR going up. For instance: I used a recumbent trainer recently. The monitor said 1000 Calories/hr. My HR was below 140, nowhere near my maximum but my knees did not like that strain and I had to back off.
What I am trying to say: The HRM is not where it is for many fit bikers. We have other issues.