I'm wondering if the tire(s) had gotten hard. It happens, and you don't know until the traction goes away. Heat and age are the biggest factors. And, I would assume that different compounds react to the heat/age. The bike tire that got hard was not old, but had gone through one of our Texas summers. The first cool day we had in October. . . . it would break loose going around curves. The tire(s) I had on the Jeep, were about four years old with low mileage, but suddenly had almost zero traction in the rain. In both cases the tires were replaced, and everything was back to normal. Now I pay more attention to the ages of tires, and how much heat they've seen.