The universe heard my readiness and replied: “Neener neener neener.”
After fixing the front flat, I did something I rarely do: I tested the patched tube by holding it underwater to verify that the patch was good and there were no other leaks. I didn’t do something I normally do: I neglected to sweep the inside of the tire for stones or other possible problems. Maybe at some level it seemed unnecessary because the cause of the flat was so distinct and discrete — I pulled a pushpin out of my tire. But, truth is, I didn’t think about it one way or another.
And my tire flattened as I was riding it to work this morning. The leak was slow enough that I could limp to work by pumping it up along the way (not recommended procedure, but tolerable for very short distances.)
When I patched it again tonight, I found three tiny holes, probably caused by the grit I found in the tire. A commenter to the post linked to above recommended kevlar tires; I am using a flat-preventive already: Mr. Tuffy tire liners — a tough plastic strip — which are encapsulated in old inner-tubes. These lie inside the tires, between the tire and the tube. They normally do a really good job — until this week, I haven’t had a puncture-flat in over a year, and, then, it was because I picked up a nail. I now suspect that one of the things that happens with the liners is that they allow a lot of grit to accumulate between the liner and the tire, so one has to be extra-careful to clean it when it has the opportunity to get loose. Probably the cause of the holes in my rear tire was because I over-inflated it, which shook loose some grit that had been trapped.
You know how miserable some people get when their cars are out of order? Well, I’m at least that miserable when my bike is, and it’s a great relief to have it back in order. This time, I’ll refrain from commenting on my readiness for it to continue that way.