Freewheel down a known gradient ( through still air ) on the Diamond Frame and note your ‘Equilibrium Velocity’.
Repeat on the recumbent and you’ll find your EV is faster.
This is because the ‘bent has a lower Cd. It will have a lower CdA and therefore require less Watts to maintain a steady speed on the flat.
The Brommie will have a higher Cd again, having a larger X-Section area, cus you’re sat more erect than the Touring DF.
Well yes, obviously. That's why recuments are good on the flat. I think the Brommie's losses over the DF are more from the small wheels (which are truly awful on certain types of road surface), silly suspension and gears-inna-can, though once you do get some speed up it is like riding with a parachute.
But I'm thinking more about climbing, when it's basically weight vs power.
What's interesting that it's subjectively easier to work at a higher power output (assuming that's what the heartrate is reflecting) in a more upright position. Not sure if that's psychological (ie. that I'm trying to maintain a habitual speed and cadence in spite of greater power losses) or biomechanical. Which is why it'll be interesting to see how Kurt gets on.
