Got a friend with a 900rr and he is in need of a rear sprocket. Is it true that when you replace one you need to do both? Also, someone explain to me the one up or one down on teeth, I think stock is 43T. He has this thing about riding down the road on one wheel. So I was wondering if it would help to either go up in teeth or down, whichever the case maybe. Thanks for any info!

 

I think some people recommend replacing both.

That's what I did and got a quick acceleration kit from RK I believe.

The front sprocket had one less tooth than the stock front sprocket and the rear was stock if I remember right.

That is supposed to add more grunt down low, but it sacrifices top speed.