I am looking at buying a '96 Cannondale T400 for my girlfriend. We're not able to ride the bike before buying, so I'm relying on you guys to answer a few questions about the sizing. She is 5'6" with a 31" inseam. The T400 I'm looking at is 19" with a 19 1/2 in top tube. Would this bike be a good fit for her as far as size is concerned? She really likes the bike ,but we don't want to buy it if the sizing is way off. She rides a 17 inch Specialized Hardrock right now. We won't be using the bike for touring, it will be used on the local bike path and a few reasonably paced (slow) group rides. Any info you guys can give me is greatly appreciated!