You don't need a dedicated track hub lockring spanner if you have a (fairly common) Park HCW-5 bottom bracket lockring spanner. The three-pronged end actually works fantastically for tightening fixed-gear hub lockrings (or at least it does with my Dura Ace lockring). It's a bit of an odd usage, but it's treated me very well so far. The other end of the tool has too large of a radius and will slip off of the lockring and chew up your knuckles and round off the lockring's groove.