Hi. I am narrowing down options for my next bike purchase. I am leaning toward a Specialized WSD because (some of you may object to this) it is just the easiest option. Best bike shop in town carries them, feelings of loyalty, dislike of other shops, good deal offered. Here's the deal: I am 5 feet 5.5 inches. I understand this to be among the most average sizes of women across America. Yet the 51 feels small and the 54 feels big. Can this be solved through proper fit (of course the shop says so)? Or should I make the painful switch to another brand. Most other brands still have the 51/54 problem, however.