I'm having a lot of trouble with this. I'm interested in buying this frame to modify with S&S couplers (so don't suggest any Al alternatives!), but the sizing is really funky.
When they say these things run long in the top tube they aren't kidding.
Ordinarily I ride, in a road bike, a 52cm frame with a 535mm horizontal top tube measurement. Acknowledging that because the bottom bracket is higher on a cx bike, I would anticipate getting a slightly smaller frame. However, the Soma Doublecross 50cm has an eff top tube of 548! Good lord! I can drop down to a 48 (which no one carries apparently) and get a eff top tube of 540, but then the chainstays all of a sudden get small.
Typically, at least with road bikes, smaller than 50cm means that you can't fit 622 wheels (700c) without compromising the geometry of the bike.
This is giving me quite a headache. No one has any built up frames that I can simply test ride.