Originally Posted by
Bacciagalupe
Must be a miscommunication -- I haven't discussed elliptical or oval chainrings in this thread. (As far as I know, the data on those is inconclusive.)
Just the actual power data from strain gauges in pedal-based power meters.
Here's a vector map for a typical (clipped-in) pedal stroke. You'll notice how on the upstroke, there is still negative force applied to the pedal.
[pictures]
Your math is slightly off, in your favor; each leg is 10% of your body's weight, not 15%. Still, let's say it takes 75N to lift your leg @ 90rpm. That's a significant amount of force in this context, yes?
You might also note that as cadence increases, the amount of effective force per rotation also decreases. We see the same thing with low cadence as we see with intentionally pulling on the upstroke -- the force is greater, but overall gross efficiency is lower. Similar to with foot retention, mashing
feels more powerful, because each pedal stroke
is more powerful. As an overall method, though, it's detrimental.
Huh. Everything I find is saying they're heavier than 10% This being the most concise example:
http://www.exrx.net/Kinesiology/Segments.html
But that's beside the point, really. I don't think it matters for the discussion.
Yes, that 75N would be significant amount of force given the maximum is around ~425ish. I buy that. But keep in mind that you would need that net 75N upward in order to get your leg back to the top of the crank - whether that force is made by your lifting or pushing and transferred through the crank is irrelevant. My thoughts were that adding a little more would be beneficial, but I also looked back at the articles you cited earlier - if we were having this discussion during the academic year I would have already ordered those articles through the university, but alas, no luck =P I'm wondering how their efficiency is measured - by measure of what to what. My thoughts are that if they're just pedaling faster, it makes sense that it would be less efficient, but something that we would totally be able to support. <- That sentence doesn't make much sense, but I just mean I don't really have much to construct without a better look at that article.
I'm really surprised that there isn't more consistent force applied. I FEEL like I do a much more consistent force than that diagram shows, but of course I couldn't tell you that definitively, and it would just be me. The closest I have to real evidence to that is even when using cages (commuter bike) I find my feet slip out the back since I'd started using SLRs. Still, you're going to have me very pedal-conscious on the next few rides XD