Originally Posted by
highroller
The tube had a small hole but I couldn't find any penetration mark on the tyre tread after thoroughly examining it with a magnified glass for over 30 minutes. So I dont know how the puncture happened.
One way to find the object that caused the puncture it is to run a cotton ball around the inside of the tire. The cotton will snag on whatever caused the puncture. Two likely candidates are a small piece of glass or a short wire thrown off from the blowout of an auto or truck belted tire.
It's a good idea to always carry a spare tube and a patch kit. No tire is puncture proof, not even Schwalbe Marathons. Other things besides simple punctures can damage a tube.
Hitting a large piece of glass or metal, could cut through the sidewall. Bumping a valve or bending it when you fill the tire can damage the valve stem where it sticks through the wheel. Hitting a pothole when there isn't enough air in the tire can give you a pinch flat.
A spare tube plus a patch kit is easy insurance.