I rode a trial back in May which was quite muddy and the TL01 did fine - better than I expected. I weigh about 190lbs with gear and usually run 4psi in most rear tires, but 2.0 to 2.5 in the TL01. I think your weight and conditions (wet/dry) will influence how much psi you'd run. The remarkably stiff sidewall makes them a total pain to change, but hopefully they will be less likely to get cut on rocks or other sharp objects. We don't seem to have the old 803s anymore, so it's a choice between this TL01, a $300 Michelin, or an IRC. I bought an IRC recently and it wouldn't hold air. One of my friends had his fall completely off the rim 2 miles from his truck. We should start a new thread on this subject; I'd like to hear others' experience with the IRC.