For those of you who racer or do track days, what sprocket sizes do you run? Stock? Or does it depend on what track your on? I'm going to replace mine and figured I'd get what is used on most track bikes.
It depends on the track, but I'd recommend that you get 15/45. That combination will work pretty well at most of the tracks around PA (Summit, Beaverun, Nelson, VIR). It's what I ran on my 99 SV probably 80% of the time.
I run 14/47 at Loudon along with some other guys, a few stayed with the stock ratio. It's a short 1 1/2 mile course with lot's of turns, so lower gearing allows me to be a bit higher up in the rev range. It also means more shifting, but I like it. Can be "twitchy" off the line if you're not careful with the clutch/throttle.