I have a Black Mountain Monstercross built up as an allroad bike. I bought it as an experiment (it was cheap) but it is my favorite frameset ever. All my previous framesets were full custom, but the BM is super smooth riding and really lively, and it fits! Unlike Surley and most other production steel bikes these days, this one uses thinner gage steel. 28mm TT, 32mm DT 9-6-9 in the main triangle on the 64cm. They also have a road version (smaller tires and caliper brakes).
Black Mountain Monstercross