When climbing the tandem I can get my HR arbitrarily high, but can sustain 140 or 145. Of course I'm using some upper body and aerodynamics are negligible. I can do this in a pretty broad cadence range, but obviously like 80+
When were in the flats I can't hit much more than 130 without spinning out my wife; If power is somehow proportional to HR, I can't generate the power at 80 rpm in the flats that I can on a climb. My hypothesis is that in the flats the deceleration as the pedals come over the top is significant and causes the torque versus rotation profile to be broader versus the profile when climbing (also, the proportionality of force versus speed is quite different). I suspect this is more pronounced on the tandem, but I'm an old, lazy engineer and I really don't want to think any harder than I already have.
Does anyone else experience this phenomenon or am I just crazy?