Originally Posted by
pallen
In my experience, sometimes the cause of the flat is easily spotted, and sometimes its not.
I had a tiny shard once that was buried in the rubber and couldn't be seen. I only found it but turning the tire inside out and running my finger over the inside while pressing the outside with my other hand. When the tire flexed just right, I felt something prick my thumb.
I had a tiny piece of wire once that drove me crazy until I finally found it. And it took bending the tire in all sorts of ways to expose it.