Originally Posted by
caloso
It's possible you are psyching yourself out. Unless you're under doctor's orders to limit HR, I might suggest sticking the head unit in your jersey pocket or putting it on a screen without HR and power. You might surprise yourself that you can dig deeper than you previously thought, and you'll still have the data for after the ride.
I got so much faster when I stopped using a computer that I can see while riding. I'd either think "I'm going fast enough" and lay off, or get disheartened by what I was seeing, and lose motivation to keep punishing myself. When I don't know, all I can go by is if I have more to give or not.