You can coast on a single-speed bike. It only has one gear ratio, but the gear is not fixed onto the axle. On a fixed gear bike you have to be pedaling at all times, and if your feet come off the pedals they just keep on revolving with the wheels. They are really for racing-- in bike races on tracks you are not allowed to use brakes. Everyone is tightly clustered in a pack, there are no brakes, and I guess having a fixed gear gives you some kind of tactile control of the bike in a different way.
I think a big part of it is that if you are in good shape and ride your bike everywhere in a relatively flat place, removing the most breakable part on a bike seems like a good idea. My fit roommates all have single speed bikes, and say it is pretty rare that they miss being able to shift down. I guess I understand that, most of the time I ride in the second-to-highest gear anyway. But it's nice being able to shift down when I need to. What I don't get is why I need 12 speeds for everyday use when I'm not going up any mountains or anything. It seems like 3 speeds would be just about perfect. The shifter on a bike seems like the most finicky part, without one you just have to replace brakes sometimes and grease things up every so often. Also if you're getting up to top speed and just staying there, a little more muscle-work during that initial acceleration is a fair tradeoff for a lighter bike.
My friend tried out a fixed-gear bike at the track a while ago and reflexively stopped pedaling coming out of a curve. He locked his legs, the pedals kicked, the bike flipped, and he found himself flying through the air. I have zero interest in fixed-gear bikes.
GREs are this wednesday, this is my first full weekend off in a while but it's gonna be 2 days of math and vocabulary. Going to treat myself to some good food, too. OK dan let's do this thing.
There was a weird miscommunication, maybe, with one of my recommendations, and now he is not responding to my email and I am a little panicked. I am probably overreacting, but as a professor this guy was very finicky.