If you can get beyond the trendiness, the colors, and the seemingly uselessness of having a single fixed wheel there are a lot of good reasons why the fixed gear trend has been so big. For one, a fixed gear bike is virtually as simple as it gets when it comes to bicycles. Early bicycles were actually fixed gear bikes until the invention of the ratcheting gear which allowed for coasting. With simplicity comes durability and lightness. Without the extra gears and derailleurs to worry about and carry around, the biker need not worry about these components. Some bicyclists these days still use fixed gear setups on their bikes for the winter season due to the addition of snow, water, and mud on the road that could potentially wear down, bind, and ruin the components on a conventional geared bicycle.

If you haven't ridden a fixed gear bike yet you should borrow one and try it out. A lot of people agree that with toe clips and straps, the pushing and pulling momentum you get with a fixed gear bike pushes one to ride with a constant cadence whereas a normal bike makes you lazy by giving one the choice to coast. All of this is great for commuting and daily riding somwhere that's relatively non-hilly, ie the urban commute. Perhaps its the simplicity and ease in customization and usability in an urban environment that lead to the multitude of people who picked up a fixed gear bike, they need not worry about the gears, the derailleurs or anything else. All they need to worry about is the color and that it rides. Personally, any trend that gets people off their ass and do something as physically and mentally good for themselves riding a bike is a great trend.

if you are interested in making a fixed gear bike Puma has created an artsy "tutorial" to building one. It looks better than anything I can come up with. You can download it here.

http://www.pumaville.com/downloads/book101.pdf

I'll leave you with some inspiring fixed gear bikes. Good Luck!
Du