After reading some stuff on the 63XC e-zine ( http://www.63xc.com/ ). I decided to slap on super fat 700C x 45's knobbies on my converted-fixie bike.
It feels so awesome (like riding in an easy chair) and I have more confidence on loose surface. Still can't handle logs, but working on it, carefully. When I ride on the street, my bike sounds like I am dragging a giant zipper shut for miles. Trails are like a never-ending stream of physical puzzles.
Does anyone else do this?