By the way, I run Duranos on a pretty awful road which is only 3 miles on my commute. This was an upgrade from my Marathon Supremes. I know these are a bit beefier than the Kojaks and I might try those in the future but I've put about 300 -400 miles on them and had a few punctures already and I keep them pretty inflated (110 psi). I can imagine the Kojaks not really cutting the mustard. Beat em up and swap them out?