This started happening to the Bontrager rims on my Trek also. I coughed up the dough on some Azonic outlaws, been as happy as I can be with them! On sale at wheel world for @ $250. It sucks! But is a helluva lot nicer now not worrying about it! They can really take a beating also! When I first put them on my bike, I was pushing 300 lbs.! Air, rock gardens, no problem!