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What are Run-Flat Tires? |
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Run-Flats are basically tires that help maintain vehicle mobility even after being punctured.
Most flat tires and blowouts are the result of slow leaks which go unnoticed and allow the tire’s air pressure to escape over time. If we had a way to conveniently monitor the air pressure in our tires, we would be half way there.
Today there are three technologies being developed to help maintain vehicle mobility as a tire is punctured and after. Out of the three, self-sealing and self-supporting tires are available today, while auxiliary supported systems need further research for future Original Equipment use.
Self-Sealing Tires
Self-sealing tires are designed to fix most punctures instantly and permanently Although constructed the same way as a standard tire, these self-sealing run-flats feature an extra lining inside the tire under the tread area that is coated with a puncture sealant which can permanently seal most punctures from nails, bolts or screws up to 3/16 of an inch or 0.5 cm in diameter. These tries first provide a seal around the object when the tire is first punctured and then fill in the hole in the tread when the object is removed. Most drivers will not even know that they just had a puncture because punctures get sealed immediately with these tires.
However, if there is damage beyond repair, the loss-of-air like symptoms that come with a traditional tire also apply with these tires so the driver can be warned.
Self-Supporting Tires
Self-supporting tires feature a stiffer internal construction which is capable of temporarily carrying the weight of the vehicle, even after the tire has lost all pressure. These tires require a tire pressure monitoring system to alert the driver that their tire has lost air pressure. Without this system, the driver may not notice under inflation and may inadvertently cause more tire damage by failing to inflate or repair the tire at first opportunity. In general, self-supporting tires allow a vehicle to travel for 50 miles at speeds up to 55 mph.
Auxiliary Supported Run Flat Systems
This system is under development as they combine unique wheel and tire technology for future Original Equipment vehicle applications. In this system, when the tire loses pressure, it rests on a support ring attached to the wheel. This will place most of the task of providing run-flat capability on the wheel (which does not wear out or need to be replaced). This minimizes the responsibility of the tire. The disadvantage to this system is that their unique wheels will not accept standard tires and that their lower volume will make this type of system more expensive.
Source: TireRack |
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