First of all, it’s one word, not “monster cross” (just like it’s packrafting, not “pack rafting”). Second, I’m glad to see the term spreading far and wide, in the sense I invented, that which describes a not especially technical dirt bike race or route. Do a google and you’ll see that since the original monstercross back in 2007 (the Kaibab, see above) it’s been applied to all sorts of things.
As far as I’m aware, the term was first used by Wade Beaucamp of Vulture Cycles, and may or may not have applied to the following bike. In any case, that concept struck an aesthetic and cultural cord and the usual craziness resulted. The textbook definition of monstercross as a bike (drop bars, tires in the 40s) is a non-starter on a practical level, as far as I’m concerned. The Kaibab short course we raced in 2007 and 2008 is majorily dirt road, and Fred (far right, above) showed up with 44c tires and 700c wheels on his 26″ Sycip, and a tall gear. Mark had a “classic” monstercrosser (dingle fixie, far left above). Consensus after was that a mountain bike was the way to go. Donkey Woodchuck (argyle, above) even upgraded to a suspension fork in ’08.
Point being, fatter tires with a fast tread are faster and more efficient than 45s over any terrain too rough for traditional CX tires. Lower pressures and more air volume doing what they do, namely minimize deflection, improve flotation, and thus reduce rolling resistance.
One thing I did learn from all the race organizin’ is that dirt roads in the SW are rough, even ones fairly well-traveled. It’d be interesting to design a course with enough of a balance between rough stuff and smooth stuff to make bike choice and tire size a difficult choice. It would probably require pavement. Which I’m not into (see Roman’s comment a few posts back). Best thing of all about the growth of monstercrossing and it’s cousin gravel grinding is that bikers figured out they could run a Curiak-style race (ie hard, with the focus on the riding rather than the organization) just about anywhere. With a little creativity. It is not a surprise to me that such rides have been very well received.