I am looking into chaning the gearing on the bike for top speed. I spoke to vortex about the 18 tooth front but they could not give me an estimate for the new speeds that the new sprocket would give me. I also was thinking about going down 1 or 2 teeth in the rear as well. the stock gearing for the 04 zx10r is 17/40. I was wondering if any one has done this type of thing to a similar bike or tho the 10 and what the outcome was. I would appericate the help due to lack of time and because I don't really have the money to buy a bunch of different sprocket combinations to play with.