The tires on my 2 year old mtb are really worn. Three flats in the last two days, riding on rough gravel roads. The third was a blowout. I've never had that happen before. For an instant, I thought someone was shooting at me! I was riding on a gravel road thru the woods at a pretty good clip when I heard a loud pop and I felt air rushing by me. Then I saw that the rear tire was flat and I knew what had happened. There was a 3/8" tear in the tire and tube from a sharp piece of gravel.
I put in a new tube and began to fill it with air when I noticed the tube wanted to bubble out through the slit in the tire. So I cut a 1-1/2" square section from a Gatorade bottle and slid it under the hole between the tire and tube. It got me home and its still holding air. I ordered some new tires today. Will have to ride the other bike till the tires get here.
I'm just glad I wasn't zooming down a hill at 25 mph.