A run flat tire is a flat pneumatic tire with a built-in air cushion that helps to absorb the impact of hydrostatic pressure when the tire is punctured and to keep the car wheels from locking during a flat-out emergency. Run flats are a very common type of tire defect that can cause immediate failure of the tire. They can be caused by either road debris or sudden deceleration. Run-flat tires are an integral part of every truck, trailer and car and should not be considered an option for transportation unless absolutely necessary.
The most common cause of tire pressure loss in flat-tire systems is air loss through pneumatic components. The air pockets in the tire are designed to provide tire protection against hydrostatic shocks and to prevent inflation loss. Properly designed, run flats are very robust and provide the needed traction in flat conditions. However, the excessive amount of air available in a small air pocket will result in loss of traction even with adequate tread depth and can cause a vehicle to skid dangerously across the road. Without proper air pressure, even a top-speed vehicle can experience the shock of deceleration and lose traction.
The design of run-flat tires makes them almost impossible to lock with conventional tire sidewall designs. The tread is shaped like a 'V' and the centerline is about one inch above the edge of the tire tread. The edges of the V shape are parallel to each other. The inner edge of the tread is sealed with a moisture seal inside the grooves of the wheel surface. This seals the grooves against the pressure of the air and helps to keep the tire from losing traction when the vehicle accelerating. The seal also prevents the hydrostatic buildup of salt and water droplets within the groove as well as the wheel surface.
When choosing run flat tires, the vehicle owner should take into consideration how well the vehicle handles in corners. The type of driving can make a difference on how well the tires perform. Runners are more sensitive to hydrostatic conditions than a conventionally designed tire. If the driver has to stop abruptly or is going uphill for any reason, then it is easy to develop hydrostatic problems with conventional tires.
Another important factor to consider with run flat tires is tread depth. This refers to the depth of the tread at the tread contact patch. Most vehicles that are fitted with a deeper tread are better able to resist hydrostatic build-up and cushioning. The depth of the tread should be equal to the width of the tire.
There are other advantages of running run flat tires. Some drivers may prefer them because they help to conserve fuel. They also have the potential to improve gas mileage. Runners are typically used in off-road applications and therefore have a high impact on vehicle handling. A good example is a mountain biker who wants his bike to handle well on gravel trails.
The importance of proper maintenance with run flat tires cannot be underestimated. A puncture can easily lead to the loss of tire load, which may lead to an accident. It is always wise to follow all the guidelines provided by the manufacturer's manual for the particular make and model of the automobile. Regularly cleaning the inner tube of the tire by hand helps to prevent build-up of hard water and mud. Regular checking of the pressure and condition of the tire inner tube and valve helps to determine if it is time to change the tire.
When a vehicle owner purchases a new set of run flat tires, he should inspect the vehicle carefully. He should inspect the mounting points and ensure that they are secure. He should inspect the tire for damage, loose components, or obvious signs of wear and tear. If any of these issues is noted, he should buy a new set of wheels, as the wheels are the weakest link in a vehicle's suspension system. Purchasing wheels that are too small can also lead to a loss of traction, which may cause the driver to lose control of the vehicle.