Originally Posted by
PeteHski
You are simply creating and releasing potential energy each time you raise and lower your leg. BUT you still have to expend energy in raising that leg (even if using the other leg to do it) even though you effectively get that energy back in terms of powering the bike forward. So having heavier legs raises your minimum energy expenditure required to pedal.
We should just bear in mind that there is net internal work that must be done to move your legs through the pedaling motion. Some energy is dissipated during that motion with every pedaling cycle because your legs are far from a frictionless system.
We’ve discussed this in the Singlespeed forum. FG riders know this well because they have the choice to not do this internal work and have their legs serve to brake the bike motion. Or they can do only the internal work of keeping up and just let the bike move as it would due to external forces.
For SS and other freewheel riders, we can choose not to do that internal work and we coast. If we do only the internal work, we just manage not to coast and again the bike does what it would based on external forces.
Otto