I rode in the Tour de Cure this morning. In the staging area a guy showed me his rear wheel that had, in his words, "simply exploded." No joke, either! He was wheeling his bike from the parking lot when he heard what sounded like a shotgun blast; he looked down and saw this:



I've never seen a rim disintegrate like this before, literally splitting down the center. As I checked over the rest of the rim, there were other stress fractures (I guess they were stress fractures!) all around the rim, in a line with the segment that burst. Anyone else ever seen something like this?