A quite basic question; what's the widest tire that can be fitted to a Cannondale Bad Boy 6, 2014 (with a rigid Fatty fork)? Would a pair of studded 40mm tyres (Suomi Tyres W240, 40-622) fit?
You'd have to test it out - theres enough variation in tires (esp. studded tires) for two tires to be marked the same size and one fit and one not fit.
This thread indicates that for an older Bad Boy with rigid fork was able to clear a 47 mm tire (which looks to be the largest possible), so I'd guess the answer is yes, but YMMV.