Originally Posted by
caloso
I'm going to bet you've got a radial tire wire stuck in the inside of your tire. They're practically impossible to see and sometimes you can barely feel them with your finger but they're sharp enough to poke a tiny hole in a tube when inflated to full pressure.
My guess as well. Sometimes you just can't see them from the inside. I think they retract then re-emerge when the tire is pressurized and ridden on. The key to success is accurately matching the location of the tube puncture to the tire. Then your search is narrowed. Look both inside and outside of the tire while flexing. Bright light and good magnification help.