Originally Posted by
ljsense
Even though it's something that tubular tires are supposed to avoid, my guess is that it's something like a pinch flat. If you hit something hard, the impact can still tear the inner tube.
Imagine hitting a chunk of asphalt or whatever. It collapses the tire against the rim. A tubular rim is a lot nicer shape than a clincher, but still, that old tube is between a rock and a hard place.
As for why it happens after 1,500 miles or whatever, I think just like everything else, stuff gets old. That's a pretty solid number of miles for a Veloflex Carbon.
I did consider that possibility but this is the first such issue in 40+ years riding tubulars. Also, the roads I ride are in nice condition and I really can't recall running over anything that could cause this. The tire is 11 months old, or at least that is when I bought it from the folks I have used for years - World Class Cycles. Maybe their stock is old? I went through my Garmin files and the tire has 1,954 miles. The tread is still in very good condition. The tube is very supple - virtually new. The previous tire, which had the same type of failure, only had 893 miles. Anyway, thanks for the replies and, bottom line, I'll pay very close attention in the future and take note of any significant impacts that may cause this.