The failure will most likely be a blow-off, if anything happens at all. That isn't fatal, or even very destructive, usually. When speed was everything, I ran 150 psi all the time, and accumulated many thousands of miles on a set of E2s with specialized hubs. I finally realized that 110-120 was quite harsh enough, thank you, not nearly as hard on my wrists and elbows, and I couldn't measure a difference in performance, on the road. My trackie buddies, though, ran up to 200 psi regularly without problems, but their surface was as smooth as glass...