Wheel weights: Clip-ons or bags?
Balancing all wheel positions, including trailer tires, has been documented to increase fuel economy by 1% to 2%, according to Derek Forney, marketing coordinator, International Marketing Inc. (IMI). “In fact, nearly half of a truck’s fuel efficiency related to tires comes from the trailer,” says Forney.
Balancing is one aspect of a comprehensive maintenance program that helps extend the life of the tire, says Scott Flynn, director of sales, Plombco Inc.
“Every tire should be balanced before installation, not only on the tractor but also the trailer,” notes Flynn. “Some major fleets even re-balance tires/wheels when the tire is at a 50% wear level. Trucks haul heavy loads in all types of different road conditions. These loads increase heat in the tire and decrease the life of the tire. Many things can change as tires become worn and re-balancing can extend the life of the tire.”
Eric von Brockdorff, market development supervisor for the 3M automotive division, adds serious ride disturbances such as bouncing, wobbling and vibrating to the potential problems associated with an improperly balanced wheel.
Gregory Parker, marketing manager for Perfect Equipment wheel weights, a brand of Wegmann automotive USA Inc., says well-balanced wheel assemblies can increase safety and comfort for heavy-duty truckers while decreasing fuel costs. “Whether you balance with external weights or internal compounds depends on personal preference, but whichever way you go, the important thing is to do something instead of nothing.”
Modern Tire Dealer asked several wheel weight manufacturers to provide updates on trends in heavy-duty balancing in general, internal and external balancing processes in particular, and their latest products.
(See the June 2014 issue of MTD for an update on recent legislation banning lead and mercury-based wheel weights in some states.)
MTD: How do truck tire balancing needs differ from passenger tire balancing? Are lead wheel weights an issue?
Von Brockdorff, 3M: Truck tires and wheels are generally larger than passenger cars’ and typically require more weight to achieve proper balance. An increasing number of states have proposed and passed legislation to ban the use of lead wheel weights. The change in legislation affects not only passenger tire balancing, but truck tire balancing as well. In response to the change truck tire balancers need to have other non-lead wheel weight options.
Forney, IMI: One of the biggest differences truck tire balancing presents is the time factor. It would take hours to spin balance all wheel positions on a truck. Many fleets chose not to balance, or just balance steer tires as a result. Commercial trucks often go up to 20,000 miles before rebalancing (much longer than passenger tires), if they are rebalanced at all (an additional time constraint). Using an internal method provides a lifetime balance that installs in seconds to eliminate balancing downtime.
Also unlike passenger tires, most wheel positions on a truck have a dual tire assembly. While match mounting will help to eliminate each tire’s out-of-round, it is impossible to perfectly balance both drive tires in the assembly, especially as they wear, without an adaptive method. These tires often vibrate due to the mass (entire assembly) imbalance, causing wear and tear on the truck, less fuel efficiency, and irregular tire wear.
Flynn, Plombco: There are many differences in the balancing needs of a truck tire. Tires are a big expense for fleet companies. Proper balancing reduces vibration, reduces heat buildup in the tire, reduces scuffing, and reduces cupping. Proper balancing reduces tire heat by 8% to 10% and increases tire life by 25% to 50%. Some fleets have reported a 60% to 80% improvement in tire life when balancing is included in a comprehensive tire maintenance program. That equates to substantial cost savings for replacement tires and retreads. It is also important to note weights for trucks differ from weights for passenger tires mainly because you are dealing with larger weights. While safety is important for all vehicles, large trucks are driven hundreds of thousands of miles and balancing offers many safety benefits. Lead is being replaced, mainly by zinc weights for clip-on and steel for adhesive.
Parker, Wegmann: Lead wheel weights are not an issue except for in the seven states with a lead wheel weight regulation.
MTD: What are the trends in internal and external truck tire balancing?
Forney, IMI: The biggest trend in commercial tires is the continual search for improved fuel economy. Along with increased tire mileage due to continuous balancing, truck tires realize their highest fuel economy (up to a 6.5% increase) after tires are worn 80% to the pull point. Unless all wheel positions are balanced, the ideal fuel economy and end of life fuel economy improvement will not be lost due to premature tire replacement. A continuing trend in truck and passenger tire balancing is the removal of lead weights. The U.S. Postal Service bans the use of lead in their vehicles. Similarly, many states, like Maine, choose an internal balance as a replacement for improved performance and to eliminate the need for rebalancing.
Flynn, Plombco: If you prioritize the importance of balancing truck tires, the steering tire would be priority #1, the drive tires would be priority #2 (both internal and external), and the trailer tires would be priority #3 (both internal and external). Major fleets refer to this as the “total balance.” You cannot forget about the trailer tires. That also includes retreads. While it is important to make sure the steering and drive tires are balanced, if the trailer tires are not properly balanced, they are more susceptible to tread scuffing and bumping.
Parker, Wegmann: In contrast to suburban-style stop-and-go daily driving in passenger cars, most heavy-duty truckers regularly run on cruise control while in service on the highway. The consistent speed that cruise control provides allows internal compounds to work their best. As the wheel assembly rotates consistently, the internal compound is able to settle on the spot of imbalance and balances out the assembly quite well. However, when speeds frequently increase or decrease, during passing or braking, this causes the internal compound to re-shift inside the tire causing momentary lapses in balance. Internal compounds are certainly a viable alternative to heavy-duty balancing, but external weight balancing is the best option for constant balance.
MTD: What truck tire balancing products do you offer?
Von Brockdorff, 3M: 3M now offers 3M Wheel Weight TN4029, a larger profile weight designed to be used on larger wheel footprints to balance wheels and help maintain alignment. This wheel weight is made of a flexible and conformable composite material instead of lead and utilizes 3M’s OEM-approved adhesive technology. Provided on a roll, 3M Wheel Weight TN4029 can be cut to the exact weight required allowing for more precise balancing, and a reduction of static and residual ride imbalance.
Forney, IMI: Equal, from IMI, extends tire life, saves fuel, and increases productivity with a lifetime balance. Equal balances the entire wheel assembly, providing 1% to 2% fuel savings. Equal also reduces vibrations around the tire/wheel assembly by 20% to 50%, to reduce wear and tear on the truck, while dispersing the force of the road’s impact away from the tire for 10% to 40% extended tire life. Compared to not balancing, using Equal in all wheel positions provides an estimated $7,100 tire and fuel savings for each truck per year.
Flynn, Plombco: We offer a complete range of clip-on and adhesive for alloy and steel rims.
Parker, Wegmann: We currently offer lead and non-lead clip-on and adhesive products to the heavy-duty trucking market. We are also currently exploring other innovative options that we will be unveiling to the market soon. ■