Just a thought. I wonder if there's an easy way to calculate the power output of a human pedaling on a bicycle. The only idea that comes to mind is some sort of method to sense the torque applied to the wheels, and then calculate the power output from there using classical mechanics. How would one go about sensing the applied torque though? The ideas I'm currently thinking of don'= t seem practical for installation in a normal bicycle - such as a pressure sensor at some point along the radius of the hub, sensing the arc pressure and calling that "force at radius" (torque). Or - how about pressure sensors on the pedals? The applied pedaling force i= s directly related to the torque. Human power output can be calculated from there. But then there's the issue of bogus pressure applied by the body which doesn't actually go into doing any work (for example, when standing o= n the pedals). Any other ideas? --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .