Frank, I believe that there is quite substantial benifet to correctly pedaling. What some are trying to ignore is a simple concern over the quad muscles. This is my question "If you are only pedaling on the downward stroke, why do you need your quads at all?" I know this may sound far fetched. Alot of those who first read this will denounce this thought altogether. But here is the issue...

When you are seated and only pedaling downward, the quads cannot provide any useful torque to the pedals. The quads cause the lower leg to rotate about the knee. This can only be relayed into torque while pushing on the pedals. This action is only effective across the top of the pedal. So if this is the dead spot, how are we using our quads now?

I would suspect that most of the riders that report the reduction of effort in the quads have come to realize that they have been wasting efforts with this entire muscle group. They have not been timing this muscle correctly and thereby wasting effort and generating no appreciable torque. I would suspect that riders are attempting to straighten their legs during the downstroke and wasting large amounts of effort.

Doubt this? Look at the Coyle study which showed peak horizontal forces at 90 degrees. Horizontal forces that are applied then cannot produce torque. Totally wasted effort by the rider.

Now if you look at the efftective leverage arm when pedalling only down, you find that effective torque is only possible from around 45 to 135 degrees. This means that half of the pedal stroke would be producing torque from the forces applied. Vertical forces applied before or after these angles are merely wasted effort.

This now means that to produce the required wattage, the torque produced during these angle range is double that which would be required under a constant torque application.

Remember that the quads were not firing at the correct time and thereby producing no appreciable torque. Now retime the quads to fire across the top and you would have torque. Keep in mind that this force was produced prior, but it was just not effective. The torque added during these angles reduces the torque require during the downward stroke (45 - 135 degrees) to produce similar wattage output.

First, I'm glad to see Big O is still around :)

Secondly, my spin scan graphs demonstrate LESS "smoothness" since training on PC's.

Post-PC training adaptation, the difference between the peaks and valleys has increased (at least, that is what I found the last time I was on a Spin-scan, which was about 10 months ago). What was important was that my average power output had increased, as I learned to quit trying to achieve a silky-smooth pedal stroke.

PC's taught me that smoothness for the sake of smoothness, at least the way I WAS doing it, was a mistake. Now, when I "mash down", I'm not attenuating that force with my rising foot, instead, I'm doing a better job of at least getting that rising foot out of the way. To heck with smoother, I want the average power per stroke to be higher...PC's taught me to raise my average power per stroke by NOT being smoother. Maybe "smoother" could happen on down the road for me, but, more power is what is most important.

What I'd like to know now, is what my spin-scan would show when on RotorCranks....I may be smoother on them, I may not, I don't know. If I am smoother on Rotorcranks, it would make me think that they work by reducing the so-called "dead-spot" (which I'd like to see someone re-name, in order to reflect something more indicative of what it really is...it isn't a spot that is necessarily absolutely dead...but, it is an area that coincides with the lowest effective positive crank-torque). If I have more delta on Rotorcranks, it would make me think they work by making better use of the extensors' capabilities. Maybe they work on both sections of the pedal stroke, so "smoothness" isn't changed. I don't know. I know I'm faster on them...that showed up on the flats first, now, I'm faster uphill on them, too.

I think it is accurate to say that WHEN these devices work, they may do so by benefitting different riders in different ways. PC's corrected a power-robbing "smoothness" flaw in my pedal stroke.

BTW, I see no benefits to my run by training on Rotorcranks. I saw obvious benefits to my run by PowerCrank training. Thankfully, Rotorcranks didn't adversely affect my run, which I was concerned might occur due to the seemingly increased rate of extensor fatigue during the adaptation phase. But, depending upon the athlete, some people could observe an increase in their run performance after training with Rotorcranks...perhaps if quad strength was THE biggest weakness they had...but quad strength isn't my run weakness. This is an example of what I mean when I say: WHEN any particular device/method works for an individual athlete, it doesn't mean that a particular device/method works the same way for each respective athlete.

So, to answer your question, I don't know. I'm just glad I did the hard work that PC's forced me to do to correct my particular flaw.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

I must applaud your attitude with written "discussions". Although I realize your knowledge goes a long way, I realize that your desire NOT to accurately discuss this topic is much greater. Please twist and distort this as to the best of your ability.

I stand at awe at your absolute desire to confuse and misguide others. Dwelve on........

But damn I'm hard headed........

Please explain (in simple terms and/or diagrams) how a the foot/pedal can ever be forced downward (while seated on the saddle) by the knee joint?

Awaiting your response of misdirection .................

Yaqui,

I pretty much agree with everything you said. It was just the observation of these boys who did not have a bunch of years of pedaling wrong in them or years of weight training with overdeveloped quads or gluts suggested that a more round or smooth pedal stroke may actually be natural, if trained to be so from the git go. It may be that as they mature they may tend to become less "round" to optimize power. I just found the observation striking and it got me thinking.

Frank

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Frank,
An original Ironman and the Inventor of PowerCranks

Even if you could apply equal (muscle power) torque
to the cranks throughout the circle, you still would
not get equal effective torque because at 3 o'clock,
with unweighting you have the total weight of working
leg adding to the torque and this cannot happen at
12 o'clock. As for the children's high spinscan, the
less overall power that is being applied, the higher
the numbers will be. Were these children using PC's,
if not, the fact that they were not unweighting the
idling pedal would neutralize the leg weight effect
on CT's measurement of power being applied around
that 3 o'clock area.

Most excellent redirection, my compliments.

The request still stands though, the isolation is for obvious reasons, as well as your refusal to answer the question, simple or otherwise.

The movement of the leg about the knee (while seated) cannot produce significant torque during the downstroke. The internal requirements of accelerating and decellerating the lower leg is true. In a perfect world though, this internal effort wouldn't result in any external forces being recorded (at the pedals). If this is the nature of these forces any measured forces is wasted effort. Are the horizontal forces that were recorded in the Coyle study creating significant torque?

If so please explain how?

If not, why would there not be any benifet from reducing this?

Dr. Day wrote: ....a more round or smooth pedal stroke may actually be natural, if trained to be so from the git go.

This is probably true. My 27 month old sure seems to be receptive to any and every thing that is presented to her...if she were to be on PC's on her little pink bike, I imagine she'd pick up a more circular pedalling style much more quickly than I did! I think it's also true that as one matures, the smoother spin-scan graphs will probably HAVE to be replaced by ones with more delta, coinciding with an increase in power generation.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Dude keep up the good work.