My max HR was about 190 last time I checked ... I ride most of my centuries with my HR somewhere between 130 and 160, unless I'm climbing a hill and then it is a lot closer to 190. So that's about 68% to 84%.

I'm often up around 160 at the beginning of a ride ... nerves, I think. After an hour or so, I'll settle down and relax. And I'll go up around 160 when I ride in heavy traffic.

But put me on an empty country road mid-ride and I'll be cruising along comfortably around 130-140.