Some good info here http://www.sheldonbrown.com/k7.html with regard to sprocket thickness, spacing et al
@freezing77 started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Some good info here http://www.sheldonbrown.com/k7.html with regard to sprocket thickness, spacing et al