Originally Posted by
Homebrew01
Have you ever sprinted, or attacked (or chased an attack) on a climb ? I can feel my foot trying to pull out of my shoe from the upward force.
That doesn't mean you are actually applying usable force to the drivetrain. It doesn't take a lot of force to create that sensation / subjective impression.
On longer sustained climbs, I can decide to utilize my hamstrings and pull through the bottom of the stroke.
The amount of power that actually makes it to the drivetrain in those situations is negligible.
I'm curious about these "studies" and how they were run.
Basically, they put pro cyclists into stationary bikes with pedal-based power meters, instruct them to pedal in different fashions, and measure the output. E.g.
http://www.ncbi.nlm.nih.gov/pubmed/17545890
And for bonus points, this is some raw data from Metrigear's pedal-based power meters, which show what's actually happening when you're pedaling. The right leg applies force on the downstroke; the amount of power drops to zero; and then it climbs again. When the right leg is at the 12:00 and the left leg is at the 6:00, that's the "dead spot." It only
looks like continuous force is applied to the drivetrain when you average it out.
I.e. your legs are not supplying continuous power to the bicycle. A bicycle is a two-stroke engine, and foot retention doesn't change that.