at the end of my ride the other day, my rear tire was losing air (I pumped it up a couple times w/o fixing it; rode on bars; limped home) When I looked at it, there was a hole- in the middle of the tread. But the tire has a kevlar belt! Isn't this impossible? It's a Forte (Performance) tire. I patched the tube, added a kevlar liner.

The Kevlar belts help but do not stop flats. Radial tire wire is the worst culprit followed by glass.