Me: Well, by having a single speed, it forces you to push harder, so it makes you faster.
Him: Then why not just pick a gear on your Superfly that matches your single speed gear and not shift? Wouldn't that accomplish the same thing?
Me: Yeah, technically it would. But there's something nice about how simple and straightforward a single speed is. Fewer moving parts, you know.
Him: It's not like bikes are that complicated to begin with. Even a bike with gears has to be one of the simplest machines around.
Me: [trying to think up another good reason to ride a single speed...]
Him: Well, at least a single speed is lighter than a bike with gears since it doesn't have the cogs, chainrings, derailleurs, and shifters...
Me: Um, Yeah... except that it isn't. My geared bike is 3-4 pounds lighter than my single speed.
Him: [shaking his head at me...]
Me: I guess you're right. Single speeds are stupid. And sometimes I like to do stupid things.
Look how "simple" the eccentric bottom bracket on my single speed is!