Here's a question, and I know nothing about physics:
on an SS freewheel the cranks are spun with x lbs. of pressure from your legs. with a fixed gear, they are being spun with x lbs of pressure from you legs plus the rear wheel is spinning them thru the drive train at x lbs generated by the inertia of your speed and rider/bike weight. Would'nt that mean, at a given speed, you would need less lbs of pressure from your legs on a fixed then a SS freewheel? the differnce being the energy transfered to the cranks via a fixed drive train? Does this make any sense?