Greetings. I commute/ride a 54cm CAAD10 and am absolutely thrilled with the fit. I was bike shopping today and was able to take the Surly Disc Trucker 56cm, Salsa Vaya 2 55cm, Raleigh Sojourn 53cm, and Specialized AWOL M out for a spin. The Sojourn too small (no surprise). The DT, with the stem lowered felt great. The Vaya 2 did not have enough reach though it felt okay in the drops, alebit a little squished (think it would be good with a 56cm and stem lowered). The AWOL was fine. I think I want to put in an order for the 56cm Vaya. The effective top tube length for the Vaya: 560cm, AWOL: 575cm, DT: 570, and CAAD10: 545cm.
According to this spreadsheet for the Surly LHT and DT (https://docs.google.com/spreadsheet/ccc?key=0AjcKyUe3m-FlcGRiNXJsTDFuczBYTHhNMzFXcHZrQ3c#gid=0
), I should be selecting something smaller, that is the trend at least. I know you are supposed to buy what is right for you, but it worries me that I prefer a size that is larger than my road bike and opposite a small sample of people. I have been riding road bikes for over 13 years and when I got the 54 cm CAAD10 in 2013, my 55cm Bianchi Brava was suddenly too big. Am I missing something? Is the geometry that different? Thanks!