RADIALS ON THE RISE
According to Alliance Tires, use of radial tires has been increasing within the construction industry over the past 15 years, with a slight dip seen during the recession says Steve Vandegrift, Product Manager – Construction, OTR at Alliance Tires Americas. In addition, he notes the European construction equipment market has been almost entirely on radials since the early 2000s.
The increased flotation, improved traction and additional stability radial tires can provide relate directly to improved production, explains Pompo, which helps make them an attractive option for fleets. “While there is still demand for bias tires, veterans in the industry are feeling more comfortable with radials now, which is causing the increase in demand.”
Vandegrift says the move to radials was first driven by OEMs whose engineers appreciated the technology advancements occurring in the tire market. “They realized a more flexible sidewall, significantly larger footprint, and the capacity to increase the load on these radials,” he says. “Since then, the replacement market has been picking up as machinery owners see the benefits of radials or just replace the tires that were original to the machine. Either way, it’s creating increasing demand for construction radials.”
Among the many benefits radials offer is their larger, more evenly distributed footprint. This is due to the body plies being oriented at a 90-degree angle with the bead, creating a strong sidewall that is more flexible, says Vandegrift, whereas body plies on a traditional tire meet the bead bundle on a bias, or slant. The layers of overlapping fabric create a stiffer sidewall which lifts the edges of the tread so less of the footprint is in contact with the ground.
Vandegrift notes the wide footprint and fact the radial construction distributes torque more uniformly across the tire’s circumference produces more even tread wear and a longer tread life. “The larger, more uniform footprint of radials also provides better flotation and less rolling resistance, improving fuel economy,” he says.
Research data has shown radials can offer a 16% increase in fuel efficiency, up to 20% less rolling resistance and up to 13% higher machine productivity compared to bias-ply tires.
The flexibility of the sidewalls enable the tire to better conform to the terrain, enhancing ride quality for improved operator comfort. In addition, the sidewall acts as a suspension system which absorbs shock, further improving comfort, as well as reducing machine wear. “Many customers tell us that the time and money they spend maintaining the frames, suspensions and axles of their equipment have gone down after a switch to radials,” says Vandegrift.
He says the initial cost of radial construction tires is about 20% higher than an equivalent-sized bias ply tire, however, Alliance Tires has seen radials last twice as long on job sites “so the return on investment, figured by dividing the purchase cost by the service life, is outstanding.”
While both Alliance Tires and BKT see increased use of radials, there are applications in which bias-ply tires are still the better option. The thicker sidewall of the bias tires is particularly suited for use in low-speed construction jobs where there is a high potential for sidewall punctures to occur.
“Radials are most appreciated by construction contractors who track the actual cost per hour of running their equipment—the money spent on tires per hour of operation, the amount of fuel consumed per hour on a contract, and the cost of downtime, which of course is less frequent with longer-lasting tires,” says Vandegrift.
He says radials are best suited for equipment which runs on the road, especially for long cycles, such as rock trucks and backhoe/loaders shuttled on the street. The radial’s flexible sidewall creates a broad, flat footprint for a comfortable ride on this surface type. Applications in which sidewall stability is paramount—such as machines working across slopes or telehandlers whose center of gravity shift as their load is raised or lowered—would benefit more from the stiffer sidewall of a bias-ply tire.