That the problem is the rapid generation of the heated gases in the enclosed space of the tire whether it is on or off the rim. Half off the rim it works just like using a combustible gas like ether and a lighter only a lot faster. As the tire gets older they age, they just started pushing news stories about shops selling old past the dated tires for sale and that they are coming apart as they are used on the highways at speed. Higher speed higher tire heat, bad spot in the rubber of the tire other conditions right it starts and bang.
If you think about it we do say the "tire blew" When the tire starts to go down, it starts to heat up. With the solid one piece rims, the tire shreds or comes apart. Damaging the fender area of the car. And if it was just speed and a build up of air pressure(nitrogen) from heat in the racing car tires of all kinds at 180 miles an hour they wouldn't be able to keep tires on the cars.
Same as on large trucks when a tire goes at speed on the road. It is from heat build up, which triggers the pyrolysis. Having seen two tires blow in my lifetime, being near them on the road. it is something and looked like that video only in the vertical plane.
I think that this my be the cause of a lot more tires blowing than we realize.
The deal on this and why, it isn't well known is because by the definition of it. it is more a n industrial process. It is also one that they the greenies are pushing for recycling tires and converting other biomass into energy even though it doesn't work well yet or is cost effective
Pyrolysis is a special case of thermolysis, and is most commonly used for organic materials, being then one of the processes involved in charring. The pyrolysis of wood, which starts at 200–300 °C (390–570 °F),[1] occurs for example in fires or when vegetation comes into contact with lava in volcanic eruptions. In general, pyrolysis of organic substances produces gas and liquid products and leaves a solid residue richer in carbon content. Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization.
This chemical process is heavily used in the chemical industry, for example, to produce charcoal, activated carbon, methanol and other chemicals from wood, to convert ethylene dichloride into vinyl chloride to make PVC, to produce coke from coal, to convert biomass into syngas, to turn waste into safely disposable substances, and for transforming medium-weight hydrocarbons from oil into lighter ones like gasoline. These specialized uses of pyrolysis may be called various names, such as dry distillation, destructive distillation, or cracking.
Here is some other ways to die servicing tires
Here is the original footage from the testing lab
