On my way into work one cold winter day, 12 miles in to a 14 mile commute. Suddenly I heard a huge BLAM and the back wheel got squirrly. The whole tire had ripped open in one section. I had a spare tube, but not a tire. My lesson learned was that I can be a bit overly Scrooge-like. The tire was ancient with cracks and the tread long gone, but it never before gave any problems, so ever the penny-pincher, I wasn't about to replace it. I hate it when there's no one else to blame.
Reid