Englishal
Best roc speed is dependent on many factors but the principal one is specific excess power SEP=(T-D)*V
The curves look vastly different for a piston (which I suspect is the type you have flown) and a jet.
In a jet, there is a broad range of speeds in which max roc is obtained. (In a piston, there is rarely much SEP!)
These jet speeds are nowhere near Cl max!
I restate the original question, which you have chosen not to answer:
When is lift greatest in flight (not in theory, or in a wind tunnel test)
Oh btw your reply - if you re-read what you have put, you will see that you have agreed with me (and NASA)! Tricky subject, isn't it?
Bookworm
Welcome to the debate
<You dismiss rotation on the basis of assistance from a component of thrust. That may or may not be correct depending on the rate at which climb is established>
During rotation and until unstick, although there is lift being generated, it is less than weight
At UNSTICK, the ac has already pitched-up a few degrees and therefore the lift vector is not the only thing contributing due to simple geometry. The rate at which this happens is irrelevant. So the lift is not at a maximum here.
In s & L flight, L=W. No matter what speed you are going.
So L is a max when W is a max, ie at the start of this phase.
<More importantly, how about re-establishing climb after a level off early in the flight? That takes an acceleration upwards, and the the thrust component is minimal.>
After a level-off, you will continue burning fuel, diminishing weight & therefore lift required. To establish a further climb requires an increase in SEP from zero. As the ac is rotated into the climb FROM THE CRUISE the thrust vector inclines as before and geometry takes its part again. The acceleration upwards is provided partly by the rotated lift vector and partly by a component of thrust.
To maintain IAS, there must be an increase in SEP, provided by an increase in thrust.