Mounting and Balancing Your Tires and Wheels
Whenever you buy new tires and/or wheels, you will need to have them mounted and balanced. Mounting the tires involves placing the tires onto the wheels / rims and then installing them onto the axles of the vehicle.When mounting tires and wheels, you should always follow several guidelines. First, mounting and balancing should only be performed by a trained professional using specialized equipment. Second, both tire beads need to be properly seated and securely mounted on the wheel. The wheel must not be damaged or bent. When mounting the wheel to the hub of the axle, the hub should be free of dirt or debris that might cause the wheel to be seated unevenly on the hub. The wheel should be evenly seated with all the lug nuts properly torqued onto the bolts.
Balancing the tires and wheels is the procedure of analyzing the tires and wheels to see if there are any heavy spots that would cause them to vibrate when spinning. Technically speaking, the center of gravity is defined as the point around which the entire mass is evenly distributed. The wheel is said to be in balance when the center of gravity is identical to the axis of rotation. In non-technical terms, it simply means that when the tire and wheel are mounted to the hub of the axle, all the mass is evenly distributed around the axle so that there is no vibration when the tire spins. In a way, it's similar to how your washing machine vibrates during the spin cycle if the clothes are not evenly distributed inside the washer.
To balance the tires and wheels, the technician utilizes a special machine. One at a time, the tire and wheel assemblies are placed on the machine and run through a series of spinning diagnostics. The machine will identify where the tire and wheel assembly is out of balance. The technician can correct the imbalance(s) by applying small weights to the rim at specific locations in order to even out the weight distribution.
If your tire(s) are out of balance, the quality of your ride may be adversely affected. Most drivers and vehicles are sensitive to vibrations while driving. Even minor vibrations can be annoying to many people. On top of that, when your tires are out of balance, not only can their life be shortened, but also the life of wheel bearings, shocks, and other suspension components can be affected due to the repetitive vibrational forces.
Sometimes vibrations become more apparent at certain speeds. Usually, if the vibration is caused by a weight imbalance, you will probably begin to notice it around 40-45 mph, and it may increase as your speed increases.
On the other hand, sometimes vibrations can occur if the wheel and/or tire are not completely round. If there happens to be a high spot on the wheel and also a high spot on the tire, and they both happen to be lined up with each other, then the high spot will be even more pronounced. If this is the case, the tires will experience "runout" or "hopping". If you have had the tire and wheel professionally balanced and you suspect that the continued hopping vibration is due to a wheel that is out-of-round, you can try to adjust the position of the tire on the wheel to see if that fixes the problem. Have the technician de-inflate the tire to loosen it from the wheel, lubricate the beads and then move the tire's seated position by 180 degrees so that the high spot on the tire is opposite the high spot on the wheel (like going from 12:00 to 6:00 on the dial of a clock). After re-inflating the tire and re-mounting, if the problem persists, you can try the process again by rotating the tire 90 degrees in either direction from the current position (like going to 3:00 or 9:00 on the dial of a clock). This way, if there is a high spot on the tire, you will have tried to position it at four different positions on the wheel in 90 degree increments. At this point, if the vibration problem still persists, then there is either a problem with the tire, the wheel, or the vehicle itself.