Trying to upgrade my bike component by component and hopefully have everything upgraded before winter sets back in here in the U.S... had a couple questions tho, the Trek4300 i bought came with a cassette of 11-32 8speed. i want to replace this and the Alivio Rear Derailler with some XT parts if possible...but i can't find an XT or LX Cassette with the same 11-32 teeth set on them.....if i buy a 11-30 or 11-28, what else would have to change to accomodate this? i'm a lil perplexed as to where to begin... any advice would be awesome!