I'm 5'3" and after much online research on the finding the correct frame size for my height, I found people recommending a 48cm. I recently got this road bike frame off ebay that is 46cm. after putting on 700c wheels, i found the bike to be too tall. I need to stand on my toes and cannot plant both feet firmly on the ground. if the top tube was just 3 inches shorter, the bike would have been perfect. what is wrong with the online measurements? multiple people of my height have said they fit a 48cm perfectly. how come that isn't the case for me?