I love the tires..when they keep air.I've had problems with them breaking the bead while playing in mudholes,I don't know what the deal is other than it makes a huge mess on the tire machine at work.The sidewall says no more than 7psi max.I tried running them at 4-5 psi,kept breaking beads,ran them up to 7 still the same problem.Have had better luck at 12psi but still(just yesterday) breaking beads.Luckily they have a tough sidewall and you can ride the bike with 4 flats back to the truck.Any body else have this problem?I've cleaned the rim and tire mounting surfaces no knicks or burrs they just pop when riding trails/mud holes.