Originally Posted by
Bacciagalupe
Yes, he's talking about pedaling techniques.
No, he is not talking about "steady state cruising." He's discussing the full range of riding circumstances, including track racing, climbing, sprinting and off-road. ("...force-measuring pedals show us that no cyclists, not even track pursuiters who are capable of silky-smooth pedal strokes at 130 rpm, really exert upward force when the pedal is coming up from dead bottom center.")
And the point, again, is that even with clipless, you are not applying force to the drivetrain on the upstroke (as the OP mistakenly suggests). This is a myth based on subjective experiences, and there is no evidence to support it.
You might not if you don't sprint, but anyone who sprints knows the importance of being clipped in. Take a look at how securely Chris Hoy is attached to his pedals.
I'm not aware of any studies showing how much power is exerted on the upstroke during a sprint or a hard effort up a hill but this is a simple test to do. Just do a few sprints in clipless and platforms and compare the power. No need for a formal study. I think you'll find the difference is significant.