Does anyone know if the STI shifters and the rear derailleurs are compatible with a 10-speed cassette or would I need to get a new rear derailleur and shifters if I wanted to run a 10-speed cassette? I am not to worried about the advantages/disadvantages of 10-speed vs. 9-speed. I am just curious if I bought a 2005 Giant OCR1 what would it take to convert it to 10-speed.