Norwich FG

But I didn't quite get that link Turpe? I understand that I will be tightening my sprocket but it says I won't need my lockring? But the lockring is to make the hub fixed isn't it?

It's more to do with the getting the cog on super-tight. Since most track riders don't skip-stop etc. a lockring isn't so vital - as simply going forward is constantly tightening the cog, it's only when you are resisting hard that you start to unscrew the cog. For street use, though, you definitely want a lockring and you should just torque the living shit out of said lockring. A common trick is to slide a bit of heavy piping over your lockring tool to get more leverage.