Hello PIC.ers, ----- Original Message -----=20 From: "RussellMc" >> I cogitate about how to estimate the amoutn of human effort required >> to >> produce >> that power. An `efficiency' figure if you like. > > The various methods for measuring rear hub power indicate deliverd > power but the rider also has to provide for power train losses. > Difference may be small but useful to know. > I noted that one method would be to telemeter pedal force, with one > method being strain gauges on the cranks. Producing mean power from > the delivered pulsating power would be "easy enough" [tm]. > > > > Russell > --=20 What I'm really interested in is a way to figure how much the human rider is exerting, in terms of biological power, related to the=20 mechanical power reaching the chain. It might have to include articulation functions for limbs, to show the rider how well he/she is using their available muscles. If you exert at the wrong points in the cycle you would be wasting a lot of effort, its not a given that all riders automatically know how to get the most out of their body joules. That implies strain-gauging the pedals themselves (not the cranks), sensing the crank position, and making educated assumptions=20 about muscle efficiency. Do we get better chemical efficiency from a short sharp impulse than a long low one, or vice-versa? Just how much is the rider losing through trailing pedal force, if they are not consciously `pulling-up' on the trailing foot? And if they _are_ pulling up on the back foot, how much netbeans does that take out of him? bestos, John eMail from John Sanderson's desk. JS Controls cc. Manufacturer & purveyor of laboratory force testing apparatus. PO Box 1887, Boksburg 1460, Rep. of S. Africa Tel: +27 (0) 11 023 1412 Fax: +27 (0) 86 516 9725 Cell: +27 (0) 82 741 6275 eMail : john@jscontrols.co.za Web: www.jscontrols.co.za --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .