Originally Posted By: wwillson
I rarely find the object that causes a flat in 700x23c tires. Can't say I've ever seen anything like this in dozens of bicycle tire flats over the years.
Most of my flats over the years have been caused by broken glass. I've learned the hard way to deal with my flats (excepting obvious ones like the big nail shown) like this:
1. Use a paint pen to matchmark the tire and tube position on the rim. (The tube position will be determined by the valve stem hole in the rim of course, but be aware that the tube may be flipped 180 degrees when you're putting it back on; for that reason I draw a line with the paint pen on the valve stem, the rim, and the tire, to ensure I know exactly how they were aligned at the time of the puncture.)
2. Remove the tire and tube, find the puncture on the tube, and repair it.
3. Now examine the section of tire proximate to the puncture to ensure there's no glass shard/wire still sticking through the tire. Remove same if found. The paint matchmarks should let you narrow down that area in the tire where the nail or wire or glass entered.
In the past I'd not always found what had caused the puncture, and would get a 2nd flat shortly after. GRRR!