this is what andy from surly emailed back.

"we reworked the steamroller stays to more easily clear straight arm
cranks, particularly track cranks, which tend to require a close fit with
somewhat large rings. since our frames all take larger than standard tires
for each frame type, this means track cranks will always have more trouble
fitting our frames than on standard track frames with really skinny stays,
but clearance now is decent. i still recommend road cranks, or at least
something with a bit of offset to them, but nearly every crank should fit
the gray frames. the brown ones? you may be SOL. the fit was so close that tolerance variance meant some fit and others did not. there were the usual variables, like crank type, model, length, all that, but mainly it was just tight no matter what."