Originally Posted by
Bill in VA
Every auto flat I have ever had has been from a screw. The one positive is they do not come out easily and I had had some where the heads have worn off with no loss of air (BIG kudos to Michelin tires), plus they were through the tread, not the sidewall.
All my past bike flats have been from cuts, or in the tubular days, from the stitching coming loose.
ususlly. Last year I had a bolt in mine, I was going to have pulled and patched the next day, but I was delivering a pizza, doing about 85 on the expressway, heard the ping of the head breaking off and the tire blowing out. My bike flats are usually glass, or paper clip gauged metal things.