It was a LONG Walk Home with a Failed Armadillo
I love Specialized Armadillo tires. IMO, they are the MOST debris resistant tires around. HOWEVER, they are not perfect, by any means. Besides being heavy, with poor wet weather performance, one weakness is in keeping them on the rim. I experienced this myself, as recounted here. I put that down to using the tires on an old-fashioned rim, rather than the hook bead rim Specialized specifies. However, two of the four Armadillos I currently am using have been mounted on non hook bead rims with never a hint of any problem. The third has always been mounted on a hook bead rim and has had no problems. The fourth blew three times, before I broke down and mounted it on a hook bead rim I built up, described here. It seems to be stable on the hook bead rim.
It isn’t just me. One of my fellow bike school students also had an Armadillo blow out – a tire used only ON a hook bead rim. What’s more, her experience is unlike any tire failure I’ve seen before. Namely, it appears the bead separated from the tire, with actual rusting of the bead, leading to an explosive tube failure.
Fairly New Armadillo with Catastrophic Failure
FWIW, coincidentally, I noticed a very interesting article on bike tire beads, here. Damon Rinard actually CUT the bead wires, and the tires did not blow. It was not a long-term test, but it suggests that the rubber part of the bead may be part of the culprit when it fails over enough of the circumference that the tire does not stay mounted.
What does this mean? Maybe nothing. However, I suggest that if you are getting a new Armadillo, you carefully inspect the bead of the tire to make sure there is no path for oxygen to get to the bead wire and replicate the bottom two photos. In over 40 years of cycling, I have never seen a tire fail in this manner – until I saw this one where the wire separated from the rubber.