that will gear you way down!1st gear will become like a four wheel drive in lo range,itll be like your missing 5th gear once in top,i think they got the standard gearing spot on?i tried a 37 on a cb500 that have 34 stock,thats how it became I took it straight off,your going even and extra tooth,the 500s have 17x34 stock and the 550s have 17x37,they have a different internal primary reduction but have the same overall gearing.