I have posted this query before, but thought I would try again. This past Sunday we had a spontaneous tube failure on the front wheel - the tire abruptly went flat in less than ten seconds. We had just completed a rather fast decent a couple of minutes before. It was not a puncture (the hole in the tube was on the rim side), the rim tape is good, we had not hit any hard bumps, and the rim was not hot.
A later did a post-mortem on the tube by cutting out the area of the failure and found that there was clearly a thin spot in the rubber. This was a Specialized brand 700-20/28 tube with only a few hundred miles on it.
I have had similar experiences twice before and find it alarming. So my question is - does anybody have recommendations for better quality and/or more robust tubes?