Gotta second JMD's post. I bought my S12's to cross the mud pits & creeks of our local KS & MO trails. I thought for sure one trip to Colorado would see the last of them. Well, 5 months later, I'm still riding them...on everything. Street, rocks, mud, dunes, whatever they wear like iron. Now I did just get back from riding at Chadwick, MO a few weeks ago and did gnarl them up pretty good after 2 days of riding razor sharp rocks, but they STILL have plenty of life left in them and are nowhere near needing replacement. Wild. Love to hear about the M12...perhaps even better?