Hi there, I just bought a Gary Fisher Tassajara women's mt. bike that is 15.5 inches. I am 5'3 and also have a 28" inseam. It was SO difficult to find one that gave me enough of a standover clearance. I tried the 13" and there was about 3 or so inches but the frame felt a little small. I also tried the new 2005 Specialized Rockhopper and they changed the top tube angle for the unisex one and it gave me a comfortable clearance.