Wide-base tire update
To say the truck tire industry has experienced a lot of changes over the past three decades is an understatement at best. While tube-type bias-ply tires on multi-piece rims were still a significant part of trucking in the 1980s, they are practically dinosaurs today and more or less relegated to the intermodal and off-road markets.
The tubeless radial truck tire revolutionized every aspect of the industry from service to retreading. With the days of “split rims” and inner tubes securely in the rearview mirror by the late 1990s and the turn of the century, it seemed like truck tires had reached the final frontier.
But then the price of diesel skyrocketed so fleets were presented with an entirely new set of problems. Fuel mileage became the top priority as trucking companies were looking for every extra tenth of mile per gallon that they could find. They had to find a way to move the same amount of freight more efficiently in order to maintain profitability. As a result, a new generation of an existing product was born to help them squeeze every drop of fuel and pound of freight just a little bit more.
Enter the wide-base tire
The concept of a larger single tire taking the place of duals is not entirely unique. There are still plenty of applications where wide-base flotation tires are still used on the drive axles of trucks and on trailers. Like the Budd, Dayton and Uni-mount wheels, industry slang referred to them as super singles, but that is a name trademarked by Goodyear Tire & Rubber Co. So like the proper wheel and rim terminology is stud-pilot, demountable and hub-pilot, the technical name for these tires is wide base. I had another name for them as a young technician, especially the bias-ply versions that featured thick beads. Wrestling them often led me to use language that my 14-year-old son uses when he wants to experience life without personal electronics and video games. Fortunately, they were in limited applications and the switch from bias to radial made things a little easier.
Innovation is a term that is easily thrown around because the marketing folks are experts at selling the sizzle. As someone who has been around long enough to remember some of the proclaimed “innovations” that never amounted to anything, I’m going to remain skeptical about newer technologies until they have proven themselves over time. So when I first heard about a new generation of wide-base single tires, I have to admit that my rose-colored glasses stayed in their case.
The concept of replacing traditional dual assemblies with a wide-base, uniquely flat, single tire made a lot of sense at first glance. It wouldn’t require any retrofitting so fleets could literally give it a shot with the stroke of a pen.
At first, the benefits were mainly associated with weight. Tanker fleets and other trucking operations that maxed out before they “cubed” out were the first to jump on board. With an extra 700 to 1,300 pounds of freight, it wouldn’t take long for the benefits to add up. Even with the additional cost of a much more expensive tire and wheel combination, the bottom-line savings of maximizing shipments were relatively easy to recognize.
But like any new technology, there were some early growing pains. I can still remember a Technology and Maintenance Council (TMC) meeting in Jacksonville, Fla., when the hub and bearing manufacturers expressed their concerns about not being consulted prior to the introduction of the new generation of wide-base single tires. “Expressed their concerns” is just a nice way of saying they were less than pleased with the fact that these new tire and wheel combinations changed the load point on the bearings so fleets could experience an increase in bearing failure after making the switch.
While a lot of it has to do with the outset of the wheel (the position of the mounting surface), a certain percentage of the issues can also be attributed to the type of offshore parts that are typically shipped in plain white boxes. Needless to say, it was an interesting lesson in how technology can solve one problem and simultaneously create an entire set of new ones.
The case for retreading
The next major hurdle for the new generation of wide-base tires was retreading. With limited applications, retreadability wasn’t a widespread issue, so the main difference was the width of the tread. Traditional wide-base flotation tires like the 425/65R22.5 and 445/65R22.5 have a contour that is very similar to standard truck tires used in dual positions. But the contour on the new generation wide-base tire is almost perfectly flat, which creates some challenges for retreading. The issue is that the center of the tread on new generation wide-base singles is very rigid and stiff, so the amount of flexing that occurs as the tire travels down the road is magnified to some degree when force is transferred to the edges of the belt package on a tire that is under-inflated or overloaded. Poor inflation pressure maintenance usually leads to exposed belt edges during the buffing process, which renders the casing useless.
Casing retreadability appears to be one area where improvement is still necessary. Depending on which retreader you talk with, the success rate of the casings is either improving or staying the same. Regardless, it’s safe to say that standard and low-profile truck tires used in dual positions are more retreadable than their new generation of wide-base counterparts. Fleets that choose to make the switch must anticipate a higher casing rejection rate that will depend largely on the quality of the inflation pressure maintenance program. Since there is a lot of additional stress on the belt edge, under-inflation has a more significant impact on the retreadability of wide-base tires.
Michelin North America and Bridgestone Americas Tire Operations were the first tire companies to introduce these types of wide-base tires. The most popular size was, and continues to be, the 445/50R22.5 that replaces traditional 295/75R22.5 low-profile truck tires. The 455/55R22.5 is a little taller, so it usually replaces the 11R22.5 and has an additional 800 pounds of carrying capacity. Both tires are designed for a 14-inch rim.
Over the past few years, other tire and retread companies have entered the game so we really can’t call them new any more. Many of them were on display at the recent TMC Annual Meeting and Exhibition in Nashville, Tenn. Here is a look at the wide-base market brands based on what I learned at TMC.
The 445/50R22.5 is available in mold cure highway and traction retread designs. The 455/55R22.5 is only available in a mold cure traction retread.
The 445/50R22.5 is available with traction tread for drive applications and a highway design for trailers. The 455/55R22.5 is only available in a highway tread design. Bandag has traction and highway retread designs available for both sizes.
The 445/50R22.5 is available with traction and highway tread patterns, but the 455/55R22.5 traction and highway tires are not expected to be released until 2015. Continental has a highway retread available for both sizes and expects to have a traction retread in May of this year.
The 445/50R22.5 will be available in 2015 under the Roadmaster brand in a highway tread design to be followed by a traction tire for drive applications.
The 445/50R22.5 is currently available in the highway tread for trailer applications and the traction tire at TMC is expected to be released soon.
The 445/50R22.5 is currently available with traction and highway tread designs and includes the DuraSeal technology that offers additional protection against flat tires. Goodyear has highway and traction retreads available in traditional precure tread rubber for both sizes as well as a UniCircle drive and trailer retread for the 445/50R22.5 that was on display at TMC.
A traction and highway RingTread is available for the 445/50R22.5 and the Unitread line of contoured precure flat treads has traction and highway tread designs for both sizes.
The 445/50R22.5 and 455/55R22.5 are available in both highway and traction tread designs. The 445/50R22.5 is available in either mold cure or precure retreads with highway and traction treads for both types. The 455/55R22.5 is available in precure with highway and traction treads.
The 445/50R22.5 is currently available in a highway and traction tread design.
Depending on which company you are talking with, the market is either growing or stabilized. Given the fact that a few years ago there were only a few players in the game and now there are multiple companies that offer new tires and retreads, it’s difficult to believe that the market is new any more or tapped out. However, I’ve also heard from dealers and retreaders who have said some converts are switching back to traditional dual assemblies for a wide variety of reasons.
Regardless, almost everyone I’ve spoken with over the past few years agreed that most of the weight-conscious fleets are totally sold on the concept because the economic benefits related to the extra cargo far outweigh any concerns regarding retreadability or increased tire costs.
But it would appear that there are enough fuel mileage advantages for regular fleets, like the ones that operate dry vans where the weight will vary from load to load. On a recent trip up I-95 to Philadelphia, I stopped at rest areas in Maryland and Delaware and quickly found tractor-trailer combinations with wide-base singles on tandem axles, and none of them were associated with the tanker segment where they are the most popular.
What does the future hold?
I’m convinced that the wide-base market is here to stay, but remain cautiously reserved about future growth ever making a dent in the 295/75R22.5 or 11R22.5 markets. Since they are becoming quite common, the service industry is starting to recognize it with new tools that make the process a lot easier.
While the wide-base single tire saves weight on the vehicle, it adds about 100 pounds for the technician. Specialized demounting tools have been released, but they don’t work like the ones that are highly effective on disc wheels used in dual positions. And while the standard tubeless tire irons are always reliable, they are going to require some extra muscle to lift the tire and wheel.
The lifting part of wide-base service is always an issue, so we have our first mousetrap, the Lifting Loop. Debuted at TMC by Tuffy Manufacturing, it really does make lifting these wide-base tires a lot easier and is one of the first of many technology improvements that will accompany the wide-base service industry.
While some companies are in the early stages of the fine-tuning that can only come after millions of miles on the highways, others are using that information to develop new technology that wears longer, retreads better, and delivers even more fuel economy.
It’s obvious that the major tire and retread companies need to be in the wide-base business. The wide-base market one day will be dialed in like traditional dual tires.
I remember the early days of tubeless radial truck tires when you could only count on the name-brand casings and were happy to wear out the rest. As the new players got better and closed the gap between the top and the bottom, the established brands kept improving, too.
I predict that the landscape of wide-base tires will continue to expand with new models, tread designs and retreads that incorporate lessons learned on the pavement making them more reliable and durable. I predict that significant casing durability improvement will still depend on the implementation of tire pressure monitoring systems because it’s the only way that drivers will collectively check the inflation pressure in their tires during every pre-trip inspection.
And I predict that the service industry will eventually have to follow the European-model of using tire changing machines on wide-base tires because it’s the most logical solution to the weight problem. (Seriously, these things are heavy, and demounting/mounting them by hand is going to take a physical toll on technicians. Machines are expensive, but increased injuries to employees have to be expected when servicing wide-base tires becomes the norm.) ■
Kevin Rohlwing is the Tire Industry Association’s senior vice president of training and a frequent contributor.