I just bought a road bike as I have been riding a hybrid. I am 5'1 so I had a hard time trying to find a small bike too. I was looking for a pre-owned(nicer than saying used and I don't have much money, LOL) road bike. I was so lucky that there is a guy in my small, small town that knows how to measure and fit people with bikes. He actually looked at and measured the angle of my hips, knees etc. etc. I ended up buying a kids bike(cannondale R500) but changed out the handlebar stem to a longer one. So,go into your bike stores and ask them how they measure to fit people for the right size bike. They should be able to do actual measurements to do that. I do know that there is an old Greg LeMond book that shows how to find out the right size bike. I know the book can be bought at amazon.com as I looked it up at one time. Good luck.

Tracey