Hi, more newbie questions...I got a flat today that might qualify as a slow leak. I pumped the tire up and was able to ride a couple of miles to a gas station and then pumped up my tire again and rode back several miles to my car at which point the tire was almost completely flat.

When I went to change the flat at home. I found a small piece of sharp "something," in the tire tread. It wasn't glass. It kind of looked like a piece of rock but it may have been a thorn (I didn't have my glasses on and then I dropped it so I didn't get a chance to inspect it.) Visually, I found nothing wrong with the tube and I couldn't find a hole in the inside of the tire.

Questions...

1. Shouldn't I have seen a hole in both the inside of the tire and the tube?

2. These are puncture resistant tires (gatorskins). Shouldn't these be dramatically reducing the number of flats I get? I've heard of people going several thousand miles with zero flats with these tires and I get one my 4th time out ?

3. I was riding on the shoulder that looked like it had been resurfaced with what I can only describe as "rough rock." Is it OK to ride on this?

Thanks,

-Mike