Thanks for all the great info. I had no idea that there was that much to it. The reason I was considering the change was I ride with a guy that has a mendota and he seems to pull from me on hills and his has a 9spd rear cassette. I just was browsing ebay and saw I could pick up the very same one for a little bit of nothing. Just tring to do a little upgrading but if it's all that I will pass.