In the car world, run-flat tyres have been the mainstay for over a decade. Can you believe that the first ‘run flat tyre’ was introduced by Michelin in 1934? It was designed for military use and also for armoured bank vehicles to lower their risk of being successfully hijacked.
Back in the real world, run-flats are a common fitment to modern cars. They work by having a stiffer sidewall that can support the weight of the vehicle even if the air pressure is lost from a puncture in the tyre.
Due to the way a motorcycle tyre needs to work, the development of a true run-flat motorcycle tyre has yet to hit the mainstream although there have been several initiatives over the years.
In America some police bikes are fitted with Dunlop tyres that many call ‘run flats’ but they are not true run-flats. These tyres are ‘bead retention’ tyres and are designed so that in the event of a puncture, the tyre won’t suffer a ‘blow out’, enabling the rider to use those valuable seconds to bring their motorcycle to a stop in a safe place.
An American firm have developed a polymer that you coat the inside of the tyre with before fitment and it enables the tyre to remain at the correct pressure even when punctured. The polymer instantly seals a puncture up to 5mm wide.
You may have heard of things like tyre slime and Ultraseal, which are added to your tyre through the valve. RhinoTire purports to be a stronger version of slime.
Indian company Ceat have developed a very similar product to the Rhinotire – the sticky polymer is applied to the inside of a tyre before fitment and will fill small holes in the tyre and seal the puncture.
None of these technologies are true run-flats in the way a car run-flat works but they do serve to limit the damage and hassle caused by getting a punctured tyre on your motorbike.