But if you rotated her about her hip...
so that she was facing down, then her centre of gravity would be lower. I'm not going to argue with a seasoned cyclist, but surely if you supported her upper body with a harness or some such device, then it would leave her legs free to move over a much bigger angle range, and make more effective use if them. By sitting down, her legs can't bend back greater than the angle of the seat to the upright which it's fixed to, limiting the performance. I'm just thinking from a purely engineering standpoint.
Also, such a big machine with low mass and relatively high stiffness should not be destabilised by the oscillation of a human peddling at the frequency that she was in the video I wouldn't think.
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guffguff fuckes your gradeds balls!, Fri 13 May 2011, 20:00,
Reply)
The official term for that is 'Prone Recumbent' (lying on your front)
And it's much less popular for the simple reason of being very difficult to find a comfortable position, with the added bonuses of:
1) Compacting the front of the torso when you need to breathe very heavily
2) With the knees having to extend downward instead of upward every stroke, the entire body needs to be placed higher to compensate, so you are in fact forced to raise the centre of gravity (or worse, in a bike, give yourself a higher aero profile, reducing or even negating the chief benefit of a 'bent).
3) You force the body to work harder in the rest phase of the stroke - to illustrate this, sit down on the edge of a raised surface (bed, sofa will do fine). Lie on your back, stick your legs out straight, and hold them there for a few seconds. Now roll over and do the same on your front. You'll see the muscle and bone structure make it naturally much easier to do on your back than on your front.
(, Fri 13 May 2011, 22:23, Reply)