I'll play. One hour flat efforts are hard to find where I live.

Average Speed solo - Time Trial 40K State Championships flat course some wind. Time 62:20 speed 23.9 mph
Average Cadence solo - 90
Average Cadence group 95 to 100
Average Speed group - 26.5 mph
Chain Ring sizes (eg. 50/36): TT 53/39 Road 50/34 Track varies from 82 to 96 gear inches
Cassette range (eg. 12-28): Varies depending on training or race from 11/23 to 12/27
Number of sprockets on cassette: 10 for road and TT and one for track
Age 63

As a trackie, we train our cadence. Most of my competitors, who are trackies, can spin high cadence without a problem. The ability to spin IMO is more neuro muscular than heart rate. I think your thesis may be flawed and it will depend on the group polled.