I am 5 2½ and ride a Trek 47cm. My LBS did a very extensive measure/fit kit to determine the size I need. My experience with my former LBS was similar to yours - if you can stand over it, you can ride it, eyeball type of fit. I ended up with a bike that was too big. In your case, you may be ending up with a bike that is too small. Either way, fit is very important. I think I would go to LBS where they took some measurements and did a proper fit. Jus my $.02 Good luck with your bike shopping.