I'm running them in 33s. They have 2 ply sidewalls but I don't know how thick they are. They are light and have pretty good thread for mud, rocks, wet logs and roots. They flex well on rocks. One guy said he cut a sidewall on one but I had no problem so far. They're quiet on the road with decent traction in the rain. They hold pretty well on the bead too in off-camber situations. I'm running mine at 15 psi on the trail but I don't bash them through the rocks at full throttle. I think if your rig is not too heavy with armor and don't have a high crawl ratio they're a fine tire.