Debating between the 49 and the 52 Specialized Crux carbon disc frame set. I normally ride a 51 road in cervelo, I'm 5'6" with a little under a 29" inseam.
Normally I would go with the 52 since 49 SOUNDS so small, just looking at that raw number for size, (anything in the 40's sounds really small, like for a 5'3" women or similar), but, of course, it's just a single number, and there's more to it than that.
My current Scott Team cross frame is "labeled" a 52, but shares similar measurements to the 49 crux in some areas (in others it's a bit closer to the 52 crux.) I like my Scott, and consider it to fit relatively well, but if someone were to ask me "if it's not perfect, would you consider it a slightly too big or slightly too small" - I would say slightly too big. Not much seat post sticking out from my seat tube!
For standover and top tube, my scott is right in between the 49 and 52 Crux, but the Reach and Stack measurements are quite interesting--the 49 Crux is almost identical in both to my 52 Scott.
Consequently, I'm leaning toward the 49 Crux. Thoughts please. Thank you!
(virtual) Top Tube for Scott: 525
Crux 49: 513
Crux 52: 537
Standover for Scott: 763
Crux 49: 754
Crux 52: 773
Reach for Scott: 370
Crux 49: 369
Crux 52: 375
Stack for Scott: 541
Crux 49: 541
Crux 52: 554