Did some test riding today!

[emily_in_nc]

Just out of curiosity, what about the geometry wouldn't work for you on the 46cm? That has me a little nervous, but OTOH the person selling it is also 5' 2" (and if standover was your problem, that's not an issue at all for me).

For me it was both the standover (I would have zero clearance over the top tube) and the effective top tube length. I have long femurs and always have to use a setback seatpost, thus increasing the ETT length. So I have always needed a ETT less than 20". But definitely, since standover is not a problem for you, you should try it. Your inseam is longer than mine, which should mean that you have a shorter torso, but that doesn't mean your arms are shorter -- and you might be more flexible in the hips and lower back than I am and be able to handle a more stretched out cockpit.

[Jolt]

Well, the bike swap this morning was a bust...nothing in my size that I was interested in. There was a nice Volpe but it was a 49cm and too big (darn!!). We'll see how things go with the Surly this evening.

[Sky King]

We'd probably put you on a 46 in Surly if you visited us in Boise , I think a 42 would be to small with your PBH. Suppleness of your tire is going to have way more affect on "speed" than the tire size. As already noted, a 26 or a 650B with a nice tire is going to roll just as well, if not better than a 700. A bike your size with a 700 would make for major toe overlap. - Have you read any of Georgina Terry's stuff regarding bike fit? She is a wealth of information, especially for shorter individuals
Good Luck, look forward to hearing what you came up with!