conversion

it depends on how much you want to spend and how many spare parts you have lying around. the 2 big things are wheels and rear dropouts. forward facing road dropouts make it hard to get and keep chain tension (no rear derailleur to do it for you). if you want to spend the bucks, get a local framebuilder to replace the dropouts with rear facing trackies. ive seen people use old 5/6/7 speed screw on hubs with a track cog on the track, its not ideal but it does work. the rest of the parts can be old road bits, ive got '91 chorus cranks on my trackie. hunt around your lbs and often old stock can be bought cheaphb

when eddy ruled said:

it depends on how much you want to spend and how many spare parts you have lying around. the 2 big things are wheels and rear dropouts. forward facing road dropouts make it hard to get and keep chain tension (no rear derailleur to do it for you). if you want to spend the bucks, get a local framebuilder to replace the dropouts with rear facing trackies. ive seen people use old 5/6/7 speed screw on hubs with a track cog on the track, its not ideal but it does work. the rest of the parts can be old road bits, ive got '91 chorus cranks on my trackie. hunt around your lbs and often old stock can be bought cheaphb

something easier and cheaper is to use the eccentric hub specially made for this purpose...
http://www.sheldonbrown.com/harris/white-hubs.html

Not much as eddie and wilmar said. Chain line and the rear drop out spacing need looking at if you want to race. Check out Sheldon Brown in the states for top info. There are some relatively cheap fixies on the market. Fuji track for example. E-bay also sports the odd track frame.