Originally Posted by kbarch

With a freewheel, the instant you stop working, you loose momentum in your legs and the drivetrain whether you like it or not, and you actually have to work in order to "soft pedal." A fixed does the soft pedaling for you. Also: the sound of a freewheel clicking is the sound of energy being thrown away, and if you don't hear it, it's because that same energy is being used to warm up your hub.