The following writeup is from the extremely awesome blog (link) maintained by the good folks at Pure Fix Cycles. Who better to introduce the concept of fixies than the very folks who design and make em!
People talk fixie this, fixie that. But do any of you really know what a fixie is? I do! That’s why I’m going to attempt to describe to you what these beautifully simple transporting devices are.
Fixie is short for fixed gear. What does fixed gear mean?
Well, it means that the cog is directly tied to the motion of the pedals. Let me explain. You know that little gear thing attached to the back wheel? It has a bunch of ‘teeth’ on it and the chain rotates around it? That’s the cog. On a fixed gear bike, that piece doesn’t have a bearing in it and it is fixed to the back wheel. Typically, these cogs would have a ball bearing system to allow the wheel to spin independently of the cog. On a fixed gear bike, this isn’t so.
So, on our bikes, if you pedal forward, the bike moves forward. If you pedal backwards, the bike moves backwards. You might ask, why would I want to do something like that?
Well, riding a fixie has grown in popularity because of its fundamental simplicity. Let’s just say it would be tough to build a bike with fewer parts. You might know where I’m going with this, but fewer parts means…lighter!
Fixed gear bikes are significantly lighter than 9 speed all-terrain bikes, etc. It’s not all for show, either. Riding fixed allows you dramatically improved maneuverability. Riding fixed, in many peoples eyes, is the most fun part of their day. You feel attached to the bike (which you are, sort of). Since your pedals are directly tied to the movement of the wheels, you’re much more a part of the bicycle than you are on a single speed cruiser or something of the like.
Another advantage of riding a fixed gear bike, besides the increased maneuverability and lightness, is its efficiency. Fixed gear drivetrains are more mechanically efficient than any other bike, with the most direct power transfer from rider to the wheels. Efficiency means energy and highly efficient means our bikes require less energy from you, the rider.
– read the rest of the article on on the awesome Pure Fix Blog