Originally Posted by ReneV

I just went through the same set of experiences. For me, the holes were all next to the valve, on the rim side. In most cases, they were in the joining of the valve segment to the tube proper, depending on model specifics. And, in all cases there was a wavy shape left in the tube. I sort of concluded that the problem is that the tube is not sitting flush and/or straight around the valve hole, which has left enough room for the tube to bulge out when inflated to somewhere above the 80-100psi where I've noticed the problem.