Also note that fixie != track bike. Fixies are often some converted something-or-other (one of mine is a road frame, the other an MTB frame), where a true track

Also note that fixie != track bike. Fixies are often some converted something-or-other (one of mine is a road frame, the other an MTB frame), where a true track bike has a track-frame, which has a specific geometry and BB height (BB== bottom bracket, where the axle between your cranks goes), and may not even be drilled for accepting brakes, and certainly not fenders, etc. I don't know the people using the velodrome, nor the rules for it's use, but it may require track bikes. Investigating, at least one velodrome[1] says road bikes may be used, but not during track bike sessions. Point is, the subtle differences you do (not) observe between the bikes on the street and the bikes in the velodrome may be a cultural world apart from each other. [1] Oregon Bicycle Racing Association http://www.obra.org/track/information/ http://www.obra.org/track/information/