Find out all there is to know about wheel balancers.
A shaky steering wheel can indicate that a car's wheels are not properly balanced, according to Consumer Reports, but wheel balancers can be used to correct the problem. Uneven distribution of tire mass can lead to wheels becoming unbalanced and thus grinding or vibrating. Unbalanced tires can contribute to tire wear and front-end problems in a vehicle. Wheels can become unbalanced due to simple road problems, such as hitting a pothole, and balancing wheels can improve how smoothly a car drives.
There are two kinds of tire imbalances: static and dynamic. Static imbalance occurs when there is a heavy or light spot in the tire tread, causing the tire to roll unevenly. Dynamic imbalance occurs when the defect occurs on either side of the tire, causing the wheel to wobble from side to side. Either problem can be easily corrected at auto shops offering wheel balancing.
Commercial tire businesses say that a tire's balance can be thrown off by as much as half an ounce of uneven mass in the wheel, creating a need for wheel balancers. Lighter cars and tires often need wheel balancing more frequently. Both clip-on and adhesive weights can be applied to correct the problem.
Automatic wheel balancers are another potential solution. These wheel balancers use steel balls to recalibrate the tire's balance, according to a journal article by the Swedish Institute of Production Engineering Research. Business.com, a business search engine, offers a lengthy list of companies selling wheel balancers. Wheel balancers add weight to a wheel to compensate for uneven rubber weights, a problem that can occur in the tires during manufacturing. According to the book TechOne, by Don Knowles and Jack Erjavec, most wheel balancers require the tire to be removed from the car. Tread defects and objects in the tire can deter proper wheel balancing. According to the book Automotive Suspension and Steering Systems, by the same authors, some electronic wheel balancing requires the tires be rotated by hand. Others rotate the tire electronically with a motor. Wheel balancers locate the heavy spot in a tire that is throwing off the balance, and weights are affixed to correct it. Some wheel balancers are electronic motors that are positioned on the tire.
The book Automotive Services by Tim Gilles further explains that "dynamic wheel balancing" allows a mechanic to pinpoint the wheel's vibration by spinning it. Computerized wheel balancers are often used. The Equipment and Tool Institute, a trade association, provides definitions and recommendations for wheel balancing. The Institute suggests that wheel imbalance occurs when a "vibratory force" exists on the wheel's bearings. The imbalance is corrected with wheel weights, or balancers.
According to the non-profit Ecology Center, tires are usually balanced both horizontally and vertically, using two lead weights that are 20-25 grams each. Such weights add up to 70,000 tons of lead per year worldwide, which has caused environmental concerns. Wheel balancing, however, is a common mechanical technique used to improve vehicle ride and prevent future deterioration of tire tread.