I currently own a stock 2005 Giant OCR3 that has Shimano Sora-level components. I purchased a 2007 Mavic Ksyrium Equipe wheelset from someone locally. The wheels are a takeoff set and came with tires and and a rear Shimano 10-speed cassette installed. My question is, can I just install the rear wheel with 10-speed Shimano cassette or will I have to put a 8-speed cassette on the wheel? Basicly, Are Shimano cassette's interchangable? If not, can I use a spacer? If so, will I have to adjust the rear derailleur or chain?