I know there's already a lot of Surly love on this thread but I'd just like to add my 2 cents. My friend is a little shorty and has a 42" LHT. She LOVES it and says it fits great. Here's my friend (our other friend for scale, he's about 6"):

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Aaand here's her LHT (we call it the MiniTrucker):

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She said the moustache bars took a little getting used to but are comfy for her.

As for me, I'm 5'5" and love a good steel frame. My BF and I do long rides together and he's got a LHT that holds all our stuff, so I'm spoiled in that I can go very minimal on road trips since he's my built-in SAG. I was on a tighter budget so I picked up a ready-to-ride 1984 Nishiki mixte for $150 on Craigslist, which solved any "can I fit this top tube" issues, cleaned it up, and kitted it with a spanky new wheelset and cassette. It's certainly fast enough, very comfortable, and I did a 70 mile ride on it a couple weekends ago without my tush or any other parts of me complaining. If you're on a super tight budget, going vintage may be a good bang for your buck, and mixte frames are very short-lady friendly while still being strong and offering good ride quality.

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