the newer bikes run different ratios to the older steel frame models. Im pretty sure they are geared longer.
where the 06 came out stock 14/50 the 08 came with 13/50
stock 06 14/50 tops out a little under 80. 15/50 takes you to 90 on the gps.
Ex 650R, Ex 950SE, Ex 950ADV
Ex SM610, FS570, WR450, Africa Twin(s)