Damn that sucks on the valve issue!!! :eek1 FWIW, I dont adjust pressure when riding in dirt, rather modify positioning and posture I guess. I usually run between 25-30 psi everywhere. I'm about to turn over 3500 miles on my first set of K3's with about half tread left on the rear. Front still looks brand new. Sweet freaking tire! When they burn out I'll buy another set. I'll post up pics later.