Originally Posted by
brett jerk
I've heard this argument before, but it doesn't make any sense. It seems that you would lose more energy this way than with a freewheel, because of the energy loss to the complete drivetrain system as the energy is transferred to the chain and then to the crank arms, verse the rearwheel on a freewheel which would only lose energy to the freewheel itself. I am not going to argue that climbing isnt easier on a fixed gear, but I think this is because you don't lose any energy in your pedal strokes in the gap between your cadence and the momentum of the rearwheel (if you could pace yourself properly going uphill it shouldn't make a difference whether you're geared or fixed). This, however, has nothing to do with the bike pushing itself.
Personally, if I'm climbing in the same gearing on a singlespeed vs. a fixed gear, I believe that the momentum contained in the fixed gear system is more beneficial then if I pedal, coast, pedal, repeat on the singlespeed.
Admittedly, it also depends on your ability to pace yourself. You can go hammer hard, coast, hammer hard on the singlespeed, or just maintain the same level of input into the fixed gear system. In fact, I think you could put LESS energy into the fixed gear system as time elapses during such a climb to, for example, maintain the same mph. The momentum from the previous revolution at timeT1 is still apparent in the system, so that at timeT2 less energy is needed to maintain the same mph vs. coming off dead (or even coasting). I'm not saying it's a perpetual motion machine.
Even if I'm completely incorrect, I think a better comparison for mileage over the same amount of energy input is a single-speed vs. a geared bike, as both allow for coasting.