Originally Posted by
cyccommute
Because 50mm tires don't fit a lot of frames that aren't mountain bikes. A mountain bike isn't a bad choice for the C&O but it is a bad choice for touring on paved roads.
OP Vexxer has a nice stable of bikes, I'd guess a used MTB would be in financial range & most bikers know somebody with little-used MTB to borrow. Anyway if using a road/cross bike I'd think about stuff like extra padding in handlebar tape, saddle etc, maybe even a Thudbuster seatpost Or perhaps forgo C&O & just do GAP plus side loops or whatnot?