Originally Posted by
AlmostTrick
A fixed gear cog is "fixed" to the hub, as in locked to it. So no freewheeling and no coasting, ever. Any time the bike is rolling you are pedaling. It's a great feeling! Single speed has a freewheel and you can coast at any time.
It's hard to describe (and no, I will not use the word "zen") but you really feel one with the bike. Want to go faster? Pedal faster. Want to go slower? Pedal slower. I recommended you have a brake even if you go fixed, but on a flat road, you may never need to use it.