Originally Posted by caloso

Every hub I know of that takes an 8 speed cassette will also take a 9 speed. The main thing is whether you have indexed 8-speed shifters--they only have 8 clicks. If it can be set to friction (some older mtb/hybrid thumb shifters and bar end shifters will let you switch between indexed and friction) then it shouldn't be a problem. If not, you'll have all sorts of problems shifting.