If your looking for better fuel milage and correct your speedo,try going up 1 tooth on the front sprocket(16 tooth). It still has plenty of low end.It doesnt lose any power,it just moves it up a bit,turns on at slightly higher rpm,still wheelies with ease. It also drops your RPM's for those long trips. I changed mine 3 mos ago. My speedo was 5mph fast,now its right on with my GPS. Sun Sprocket offers 14,15,and 16 tooth. I think mine cost about $25. my 2 cents.