Fixed gear: a bicycle with only one rear cog or "gear" which is fixed directly onto the hub of the wheel. The fixed gear was most popularly used as track or "velodrome" racing machine but has since made it to the streets and has seen a rise in outdoor road usage. Currently, in many large cities across the world, the fixed gear, or "fixie" as it so often called, has become the focal point of a growing urban subculture which includes bike messengers and the like. This subculture is seen as being quite countercultual even in the cycling community and is often associated with the punk rock/anarchist scene & now Hip Hop enthusiast are also picking up the sport!!
Simply put, Its Just Plain DOPE!!