Originally Posted by seat_boy
I think the bigger worry will be your wheels. Depending on how big a tire you can fit, and what kind of lines you take, they may see quite a bit of stress. I've got a nice flat spot on my Gunnar Crosshair's front rim after taking it singletracking (admittedly, with 28mm road tires)
Eric
Good point. Who really knows what is under all of those pretty leaves. I use 32s in the front and a 45 in the back. A good rock or root could do some wheel damage.