I'm now to +2 on the back sprocket which should give me a little bit extra oomph without going crazy. I did a little mental math this weekend (long ride home!) and figured that my mechanical limit was 170mph stock but I've only been able to hit 160mph because of wind resistance. Even without the tail bag and backpack, I probably wouldn't get above 165mph. The +2 cost me about 5mph of top speed so now I figure I've got the same achievable top speed but I'll get there a little quicker. Gr8Dane and I just installed our SpeedoHealers too. We've adjusted them for the gearing changes but will have to find an officer friendly enough to clock us sometime (on good terms) to account for factory speedo error.