Trek's mens bikes go down to 50cm and you could look at teh WSD models which go all of the way down to 43cm. I think the only difference between the men's and womens WSD is a different seat. At 5'6" I would think a 50cm or 52cm frame would fit. I am 5'7" and I ride 54cm frame which fits perfectly. I think you can find the Pilot 1.2 or the 1000 in your price range.
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The problem with the gene pool is that there is no lifeguard and the shallow end is much too large
2013 Noah RS