The ride and comfort of today’s modern commercial trucks far surpasses that of previous generations. IMI’s Asa Sharp discusses these improvements, and why, even with these advancements, it’s still important to consider wheel balancing options for commercial vehicles.
Transcription of interview:
Erica Schueller, editorial director, Fleet Maintenance: Welcome to VSP News: Uptime Update. I am your host Erica Schueller, editorial director of Fleet Maintenance magazine, covering all maintenance, all vehicle classes, all management, all the time.
The ride and comfort of today’s modern commercial trucks far surpasses that of previous generations. Those ride improvements can be attributed to improved quality in radial tires, developed for specific use cases including the drive axle, steer axle, and trailer axle. Plus, the increased spec’ing of aluminum wheels over steel has helped to maintain a uniform tire-wheel assembly while reducing vehicle weight.
I talked with Asa Sharp, OEM account manager for IMI and long-time commercial tire industry advocate about these changes, and why, even with these advancements, it’s still important to consider wheel balancing options for commercial vehicles.
First, we talked about the current trends in commercial vehicle wheel balancing.
Asa Sharp, OEM account manager for IMI: What the industry has discovered in recent years is that, although there is a diminished need for balancing in response to a ride complaint or vibration, that balancing all of the wheels on tractor-trailer results in significant, quantifiable, and measurable fuel economy improvements.
When you think about it, it really makes sense because most all of the spinning masses on a truck are balanced – things like the crank shaft piston rod assembly, what they call the rotating engine assembly, vibration dampers, cooling fans, driveshafts, clutches. All of those things are balanced for a very good reason of reducing overall vibration, but also improving the reliability of lifecycle.
The end result is due to energy conservation. The more energy you can conserve and avoid dissipating into the surrounding atmosphere as heat, the more fuel efficient your vehicle is going to be.
Schueller, Fleet Maintenance: Achieving better fuel economy continues to be a top priority for fleets. Sharp shares additional details on how wheel balancing can assist with this.
Sharp, IMI: The Technology & Maintenance Council (TMC) has developed standardized test procedures for evaluating and quantifying the beneficial effects of some devices and practices on fuel efficiency.
One of the things that has become apparent is that even though fleets don’t necessarily have a great need to balance for ride improvement, balancing does give a significant improvement in fuel economy. By significant, I mean in the neighborhood of 2 percent or greater overall fuel economy improvement based on industry standardized testing simply by balancing all wheel ends of a tractor trailer.
That’s very significant and comparable to some more maintenance-prone aerodynamic devices, for example.
Schueller, Fleet Maintenance: To ensure fleets get the most out of tire balancing practices, there are products available to continually balance tires while the vehicle is in operation.
Sharp talks about why, even with these products, it is necessary for fleets to incorporate wheel balancing inspections into regular PM intervals.
Sharp, IMI: You can use a traditional method of balancing, which is typically lead weights – either at the rim flange or in the well of the wheel – a takeaway type of approach.
But, there is one issue with that. In the process of wearing the tread down, a typical 295/75-22.5 tire, typical on a line-haul tractor-trailer, loses 30 pounds of tread rubber from when it’s applied new until it’s taken off or pulled for retreading.
The point being, you could have the best initial mechanical type balance when the assembly is put together the first time, but becomes in need of rebalancing as the tread wears.
There is an answer for that. It’s called an active balancing material that you put inside of the tire. The beauty of that is it’s a fresh balance every time the truck comes to a rest and starts up from a stop again.
The material inside the tire redistributes itself for, essentially, an ever-fresh balance so that it can compensate for that removal of a significant mass from the new to the worn out, ready-to-be-retreaded tire.
TMC has studied that, and there is a Recommended Practice, RP 246, titled Considerations for Products Intended for Use Inside Tires. As a fleet operator, you need to be careful to understand not all products that do that are created equal.
The tire and wheel people have all had input to develop that RP 246. I would encourage truck maintenance personnel to review that and make sure they purchase the correct material for their trucks and service operation.
Schueller, Fleet Maintenance: Sharp also confirmed the TMC Recommended Practice 246, titled Considerations for Products Intended for Use Inside Tires, can provide fleets with further guidance on using adaptive balancing products in commercial tires.
Switching topics, we talked about why tire-wheel service practices have traditionally focused on balancing steer tires, and why fleets really ought to consider balancing all tire locations – whether it be on the steer, drive, and trailer axle.
Sharp, IMI: Historically, balancing tires on steer-axle only has been largely a response to driver issues of shaking in the steering wheel. The need for that has really diminished as tires and wheels have both become much higher quality, much more uniform, resulting in trucks that we all know ride the best ever in history. They seem to get better every year.
However, the real need to balance today should be focused on drive axles because on modern air ride suspension trucks, the drives contribute a much greater percentage to any possible ride disturbance in the vehicle.
Getting back to the quest for fuel economy, which all fleets are concerned about today, the priority in balancing there would be first to do trailers, second do drive axles, and the steers would be the last consideration. But all told, remember, we’re looking at over 2 percent potential fuel economy improvement for balancing all wheel positions.
Schueller, Fleet Maintenance: If you’d like to learn more about on-tire wheel assembly balancing options, check out a recent feature story on the topic by visiting the link below.
That’s it for this week’s episode. Thank you for tuning in to Fleet Maintenance Uptime Update, I’m your host Erica Schueller.
Until our next broadcast, keep up with this, and other industry topics, by visiting us online at VehicleServicePros.com.
