I think this is very much the sticking point. Shortening velocity is usually mentioned on here, but rarely explained.
That was a very concise and descriptive summary for the laymen out here.
Hopefully this directs the conversation away from “you’re an idiot” “no you’re an idiot” that pretty much derails most of the good threads on ST.
On a side note I was I really did like the H2Ofun crank thread....you just had to wade through the mess a bit. There were some really great posts....if you were willing to hold your nose and skip the others.
Cheers,
Maurice

Thanks Maurice, glad you found it helpful. Maybe Dan can make it a sticky.
Ha, I put a LOT of work into waterboy's thread. Saw it as a duty to refute each bit of nonsense and there was a LOT of nonsense. I should probably include that thread as community service for my next job evaluation!
Cheers,
Jim

He uses a highly complex CFD model and this model predicts that drag reductions due to more horizontal torso angle outweigh increased drag due to increases in leg extension. His model has been confirmed with wind tunnel testing.

No real issue with my thigh hitting my torso, but the lack of full leg extension was definitely more fatiguing. My *perception* was that my sustainable power was compromised as much as my measured drag was reduced, such my power:drag was essentially unchanged. I therefore did not pursue things any further.

Thanks Benv. Those things you were taught as a kid are true but they're not the whole story. They don't include how muscles produce force or how muscular force is transferred across joints.
First, for any specific cadence, the pedal moves faster on a longer crank than a shorter crank. Those differences in pedal speed cause the muscle to shorten at different rates while producing force. In the muscle force-velocity figure below please note that concentric force (muscle shortening) decreases with increasing velocity. This means that the higher pedal speed produced by a longer crank reduces your muscles' ability to produce force compared to a shorter crank. So yes, a longer lever would produce more torque for the same force, but the force will not be the same. It will be reduced due to increased muscle shortening velocity. So far so good?
Second factor has to do with leg extension. You probably know that you can leg press more weight if you set up the machine so that you start with your leg nearly fully extended compared with highly flexed. You can do a partial squat with more weight than a deep squat. Agreed? This is because of what is called "biomechanical gear ratio"; the ratio of the movement of the end of the limb to movement of the muscle. Most people adjust their seat height so that they maintain the same leg extension at the bottom of the pedal stroke. This results in the leg being more extended throughout the rest of the cycle and thus your leg is "stronger".
To summarize, your muscles produce more force when shortening slower and your whole leg produces more force when its more extended. These increases in muscle force minimize or eliminate the differences in lever arm. Does this make sense? Thanks again for giving me this opportunity to test my ability to clarify.

Cheers,
Jim

Just an FYI: the units on your axes are incorrect.

"He was so fast his first name had to settle for 2nd place.... (I'll show myself out....) :)"

BEST.SLOWTWITCH.POST.EVER!!!!!!!


LOVE IT!!

Neal Henderson of APEX Coaching. He also happens to be the guy who designs The Sufferfest workouts and training plans and is behind our 4DP methodology.

...please list the number of world championships you have coached people to.

No, he's not.