I thought it might help to show a few examples of what was observed while doing a "Tire Autopsy".
A tire would be received with a complaint letter. The letter might say something like " I was driving down Route 66 at 55 mph when suddenly I had a blowout. I wasn't speeding and had checked the inflation just that morning. What is wrong with your tires? There must have been a defect.The tire looked like this.
On close inspection I found what looked like a hole in the upper sidewall where the
rubber had been worn away.
Using a bent paper clip,
I was able to confirm the hole
and looking inside we can see where the puncturing item
Note a bent paper clip will fold at the bend if you try
and push it through a tire sidewall, but if there is a
hole the paper clip can follow the hole.
For this case I provided the above information and pictures.
Another complaint involve a bulge in the tire sidewall.
The location was marked by the tire dealer.
On the inside we see a lump
We can also see a dark curved line where the tire
had extra bending.
By cutting away the rubber from the inside of the tire,
down to the body cord we can now see the broken
cords from the impact.
I trust that after seeing these examples you have learned that
sometimes additional examination is required to find and
confirm the actual failure.
After doing hundreds of similar examinations it allows the
experienced examiner to quickly identify that the reason for
a tire failure was not some design or manufacturing "Defect",
but the result of external causes.
More like thin in future posts.