While designed to be perfectly symmetrical in weight, all vehicle wheel and tire combinations, regardless of size, feature an inherent imbalance - this must be corrected in order to keep the vehicle safe, efficient and comfortable.
While not always noticed when in the shop for maintenance, unbalanced wheel assemblies become painfully obvious when the wheels and tires are turning at highway speeds. The constant swaying, wobbling and bouncing causes driver distress, premature tire wear, decreased fuel mileage and, most importantly, serious safety concerns.
When operating a fleet, regardless of fleet size and vehicle size, maintaining perfect wheel balance is an important maintenance service that shouldn’t be overlooked.
I believe that there are four main goals that all fleet maintenance operators should strive for, and proper wheel balance plays a significant roll in all of them.
Safety
Fleet safety should be the number one target for all vehicle fleets. Safe vehicles are required to keep general employees, vehicle operators and other drivers on the road out of harms way while fleet vehicles are in operation.
When wheel and tire combinations are unbalanced, it can lead to heavy vehicle sway, severe vibration, unresponsive suspension systems and increased braking distance, all of which are serious safety concerns. These issues can become compounded when the vehicle weight and speed is increased.
By properly balancing all of the wheel assemblies, vehicles will ride smoother, steer more easily and stop faster, without the added stress of vehicle pull and unresponsive steering and braking.
Type of Weight
Another aspect of vehicle safety that is related to wheel balance is the type of wheel weight used to maintain proper wheel balance.
In today’s market there are three main types of wheel balance products: knock-on rim weights, adhesive rim weights and internal compounds.
Knock-on and adhesive weights are the traditional style that most fleets utilize. These weights are mostly made of lead, steel or zinc.
Interior compounds are a relatively new product, typically consisting of powders, liquids, gels and/or beads.
Some fleets have even tried to use golf balls or marbles as an interior compound on larger fleet vehicles, but the practice is far from safe and doesn’t provide the proper balance that is needed for safe vehicle operation.
Regardless of the weight type used, it is important that the wheel assembly remain balanced at all speeds to ensure vehicle safety at all times.
Traditional style, knock-on weights are the best wheel balancing product available today.
Efficiency
Efficiency, along with fuel and maintenance costs, should also be high on the list of goals for fleet maintenance operators. Ensuring that fleet vehicles drive smoothly with even loads, and with the least amount of rolling resistance as possible, is the best way to decrease fuel bills.
Unbalanced wheel assemblies typically wobble and shimmy, causing the tires to sway and bounce. The static and dynamic imbalances can significantly decrease fuel mileage and increase fuel costs.
Properly balanced wheel assemblies, on the other hand, allow for smoother driving with less resistance, which leads to lower fuel bills.
Perfectly balanced wheels and tires also decrease tire replacement costs, as well-balanced vehicles have increased tire life.
By developing and maintaining a wheel balancing schedule for your fleet, you will be saving time and money.
Driver Comfort
Wheel balance plays a significant role in driver comfort.
Unbalanced wheels will bounce when reaching highway speeds. This is felt as a vibration in the seat and steering column of the vehicle.
Over time, the constant vibration can become numbing and cause serious back and muscle pain.
Balanced wheels and tires ride smooth, without vibration, which assists in providing a vibration-free, in-cabin experience.
Environmentally Safe
Many fleet operators are currently participating in, or are in the process of beginning, environmentally safe practices.
Utilizing alternative fuels, hybrid vehicles and non-lead wheel weights are just a few of the ways to maintain a green fleet. Choosing knock-on wheel weights made of zinc or steel are the best environmentally friendly alternative.
Traditional knock-on wheel weights were invented and patented back in the mid 1930s. Since then, these wheel weights, and most adhesive wheel weights, have been made of lead.
Lead Weight Bans
In 2003, the European Union banned the use of lead wheel weights due to the fact that some knock-on wheel weights fall off and get into sewer systems and eventually end up in the drinking water supply.
The U.S. has yet to enact a national ban on lead wheel weights but the EPA is considering one. Meanwhile, several states, including California, New York and Illinois, already mandate the use of non-lead wheel weights, and others are proposing such bans.
Zinc and Steel
Consequently, fleets and wholesalers must look for non-lead alternatives. The two leading alternatives are zinc and steel.
Steel is utilized by many aftermarket businesses and OE manufacturers in North America, but on a worldwide basis, zinc is the preferred alternative. Zinc knock-on wheel weights are utilized by nearly 99 percent of all OE vehicle manufacturers in Europe.
Both steel and zinc wheel weights are traditionally coated with a zinc-based coating, which is important for its anti-corrosion properties. Without the coating, steel wheel weights will rust.
Zinc wheel weights carry their anti-corrosion properties all the way through the weight and will never rust.
Zinc knock-on wheel weights are the best alternative for lead knock-on wheel weights on small- to medium-sized fleet vehicles.
Needs Assessment
Wheel balance is pivotal in providing safety, efficiency and comfort for any size fleet. The appropriate selection of wheel balance products can also help maintain an environmentally safe fleet.
The next time you are assessing the needs of your fleet, don’t forget the role that perfect wheel balance plays.
