ORIGINAL: Bluebrew
SJ, I have a Shumacher Menace GTR onroad with the enclosed 11mm belt and let me tell ya, that sucker gets just as much crap in there as an exposed belt maybe more because the junk can get in but not out! I figured the first thing I would get if I were to ever have one would be a buttload of belts.
Unfortunately, even that is not a fully enclosed belt drive. I have an HPI R40, and the front and read belts are supposedly "enclosed" but they are not at all, and taht is why rocks and stuff get in there.
A good example of a true fully enclosed belt drive is seen on FT competition 6th scale gasoline RCs. Absolutely nothing of the belt is exposed at all and if you use silicon to seal where the parts mate together, you literally have a waterproof belt drive!
If shumaker wanted to go belt for off-road, they should have fully enclosed the belts, even more enclosed than the menace.
Other than than, they couls have gone shaft and mounted the crankshafts so that they are mounted longitudinally instead of transversely and the idler gear that couples the two engines could also function as the spur gear.