That's crazy that they're that soft at those pressures. I only run 33-35psi in my 285s and they're plenty stable. One of the tire shops around Lewisburg had a bunch of tires in the same size the to compare relative sizing. The X3s are among the tallest and I liked the look of the tread. More tread void than I want in a street tire though. That may be why they feel so loose?