By GEORGE C. ARZENTE Installation Safety OfficeMarch 24, 2011
When was the last time you checked the air pressure in the tires of your automobile, truck, motorcycle, boat trailer or recreational vehicle' Can you remember' Or maybe it was done the last time you had an oil change (or at least you hope it was). The fact is proper tire inflation is important to the overall safe operation of your vehicle.
Properly inflated and maintained tires improve the steering, stopping, traction and load-carrying capability of your vehicle. Therefore, you should maintain proper tire pressure, observe tire and vehicle load limits, avoid road hazards and regularly inspect your tires. Because tires normally lose air over time, it's important to check your vehicle's tire pressure at least once a month. Tires can also suddenly lose air if you drive over a pothole or other object or strike the curb when parking. With radial tires, it's usually not possible to determine if they're underinflated by looking at them. For convenience, purchase a tire pressure gauge to keep in your vehicle. Gauges can be purchased at tire dealerships, auto supply stores and other retail outlets.
When and How to Check Your Tires
The recommended tire inflation pressure suggested by vehicle manufacturers reflects the proper psi when a tire is cold. The term "cold" does not relate to the outside temperature. Rather, a cold tire is one that has not been driven on for at least three hours. When you drive, your tires get warmer, causing the air pressure within them to increase. Therefore, to get an accurate tire pressure reading, you must measure tire pressure when the tires are cold or compensate for the extra pressure if they're warm.
Checking Your Tire Pressure
Find the manufacturer's recommended tire pressure for your car. This information is usually on a placard on the doorjamb on the driver's side (and it is also contained in the owner's manual). It might call for different pressures for the back tires and the front tires.
Aca,!AcCheck the pressure when the tires are cold as described above, or you can just check them first thing in the morning.
Aca,!AcUnscrew the valve cap and place it where you won't lose it.
Aca,!AcPress the tire gauge onto the valve stem. There might be a slight hiss as you press the gauge down and as you release it. You only need to do this for a second or two to get an accurate reading.
Aca,!AcRead the tire pressure on the gauge. Compare the tire pressure readings you got with the specified amount called for by the manufacturer. If your tires are not inflated to the specified amount, you need to fill them to meet the manufacturer's recommended air pressure.
Every year, many riders are injured or killed in crashes caused by underinflated or neglected tires. Such tires decrease stability, limit traction and increase the danger of catastrophic failure. All too many riders fail to check their tire pressures until they notice their bike isn't handling properly. However, waiting to that point can lead to a disaster. Wise riders check their tires before every ride.
Motorcycle Tire Underinflation
Underinflation causes excessive sidewall flexing, which results in heat build-up inside the tire. Heat is a tire's worst enemy, making it more vulnerable to damage from normal road impacts and accelerates tread wear. Excessive heat can also cause hidden interior separations, leading to blowouts. And, as any rider knows, a blowout can cause a loss of control and a serious accident.
Beyond that, low tire pressure reduces the speed at which a tire maintains full contact with wet roads. This is commonly referred to as hydroplaning and is a major hazard. The reason is underinflated tires have a larger "footprint" - area of tread on the road - which lessens the ground contact pressure. This lessens the tire's ability to push water away from the tread while rolling over the road. Both motorcycle and car tires provide their best wet weather traction when properly inflated.
Underinflated tires can also significantly affect a motorcycle's handling, causing a bike that might feel stable while going straight to handle unpredictably when cornering. As a rule, cornering with an underinflated rear tire will cause the bike to oversteer (turn more sharply than anticipated), whereas cornering with an underinflated front tire will cause the bike to understeer (turn less sharply than anticipated). Either situation can be extremely dangerous for riders. Whenever a rider notices their bike is beginning to handle strangely, it's a good idea to stop and check the tire pressures.
Motorcycle Tire Overinflation
Riding on overinflated tires can also be dangerous. Overinflated tires reduce riding comfort and stability and are more susceptible to cuts, punctures or damage by sudden impacts. Overinflation can also result in uneven tire wear and reduce the tires' contact area with the road, reducing the bike's traction while cornering.
It is important to manually check your tire pressure, visibly inspect your tires for wear and damage and regularly rotate your automobile's tires. Remember, when in doubt, consult a tire professional. After all, your life is riding on your tires, so keep the rubber on the road and arrive alive.