In Search of the Million-Mile Casing

Retread consolidation, longer wear designs should benefit the end users.

EVAN LOCKRIDGE • CONTRIBUTING EDITOR

No sooner had Bridgestone completed its purchase of retreader Bandag than another such purchase was announced. In late July, Michelin signed an agreement to buy the Cooper Tire subsidiary Oliver Rubber Co. And while the purchase price of $69 million pales in comparison with the billion dollars-plus Bridgestone paid for Bandag (a larger retreader), the implications for the tire industry and for commercial tires users are just as significant.

Peggy Fisher, truck tire industry veteran and president of TireStamp, the tire data analytics company, says this acquisition increases Michelin's retread locations from 77 to 259, and its retread market share from 12 percent to 21 percent. While that's not even half the 45 percent market share Bridgestone now has with Bandag, it does allow Michelin to nip on the heels of the nation's second-largest retreader, Goodyear, which has 27 percent of the market.

Asa Sharp, retired Goodyear engineer turned independent trucking consultant, says this continued consolidation in the retread industry is not just a benefit, but a must. "It is becoming more a necessity that new tire technology and retreading technology become more closely linked in terms of selection of parameters, such as more exact tread width and more exact tread pressure distribution across the footprint of the retreaded tire, to try to match the design and characteristics of the original tread casing," he says.

Fleets today are looking at million-mile casings. With that expectation, retreaders know they have to pay attention to the details of materials selection, materials compatibility, process compatibility and matching of retread technology with the new tires.

The more sophisticated retread technology also extends to the issue of casings repaired as they are prepared to be retreaded, Sharp says. This ranges from minor nail hole punctures all the way up through section repairs to the casing and buzz-outs in the belt area.

"Retreads are in the final stages of emerging from [what was] more or less an aftermarket technology application to very sophisticated technology, materials and processing, with a special eye on compatibility with the new tire casing."

New Tire Guaranteed

Michelin's purchase of Oliver isn't the company's only recent big announcement. In late August it unveiled the XDA5 drive tire. Despite Michelin's estimate that it will cost 5 percent to 10 percent more than its other premium drive tires, it's guaranteed to last 30 percent longer. With expenses in trucking continuing to rise along with the price of new tires, it deserves serious consideration.

Don Baldwin, product marketing manager for Michelin North America, explains the tire has a single molded tread where this regenerating feature is molded in. "We have our matrix siping in which, as you wear down through the tire, new edges are revealed, because it zigzags in two dimensions, if you will. It zigzags in depth and it zigzags across the face of the block. As you go down, it changes angles and reveals new edges. At 10/32 of an inch, you actually reach a raindrop-shaped groove or channel that allows for very good wet traction even with a quarter of the tire life left."

The footprint of the XDA5 is nearly an inch wider than the previous tire in the XDA line. The belt package is also wider, giving the tire additional life. "One of the things that causes wear is the tread squirming as the truck moves down the road," Baldwin explains. "By having a wider belt package, we can stabilize that tread and eliminate wasted motion in the tread area that would cause wearing away of the rubber." The XDA5 also has a longer-wearing tread compound.

Michelin believes the new technology will give truck owners the confidence to leave these tires on past 10/32. "Many times fleets and drivers make decisions in terms of what they see," he says. "When most drive tires get to 10/32 or 6/32, they get a ribby look without much siping and grooves left, and the drivers really think before they hit the road again, they want to get new tires on there. This will give them the confidence to run the tires out to 4/32, resulting in an additional 80,000 to 100,000 miles on these tires."

Michelin says this technology is designed for drive tires and does not anticipate using it on free-rolling steer or axle tires. In the case of steer tires, they also have to have good lateral grip, which requires different tread designs and compounds.

The XDA5 in the 275/80R22.5 and the 11R22.5 sizes are already on sale. The 11R24.5 becomes available this month, with the 275/80R22.5 hitting the market in mid-November.

This new Michelin tire will no doubt get other tire makers looking seriously at ways they equal or better Michelin's claims. This and changes in the retread market all mean one thing – better products for the customer from tire makers and retreaders that want to remain in the game.