Two-Piece OTR Radial Ready to Hit the Market Says Goodyear

When Goodyear initially unveiled its two-piece OTR tire prototype – an interchangeable tread and carcass combination ®“ late 2000, it knew the concept’s future depended completely on proving it could work.

After two-and-a-half years of development, testing and creating all-new equipment to produce the tire system, Goodyear’s new Two-Piece Assembly, as it is called, is headed to market.

Tom Walker, Goodyear general manager of global OTR tires, says the official launch of the line will come in the next few months with a size 45.00R57 product. Two other sizes – 40.00R57 and 46.00R57 ®“ are being developed. Walker says Goodyear expects to sell out its existing stock of the product, and, based on market response thus far, is scrambling to increase production to meet expected near-term demand.

Not bad for a tire concept that hadn’t been tried in real life before – or for one that required all new manufacturing processes and equipment.

It was an educated gamble Goodyear was willing to take, says Walker.

The Two-Piece Assembly consists of two separate components: a tread belt and a carcass. Mated together, they resemble any other haul truck tire. But it is their individual nature that delivers cost-saving benefits to end-users, says Goodyear.

Two-Piece Assembly targets users that are less "concerned with front-end price as they are with lifecycle costs," says Rob Andrew, global OTR marketing manager. Goodyear plans on seeking a premium price vs. conventional OTR tires because the system "delivers a very competitive operating cost even with a higher acquisition cost."

One major cost savings, Walker says, comes in reduced downtime and the potential for longer carcass life, important factors to mine and quarry operations that are production-cost sensitive. If a conventional tire goes down and has to be changed in the field, it takes around eight or nine hours, he says.

With the Two-Piece Assembly, a tread belt can be changed in half that time, he says, even on the inside tire of a dual set. Plus, tread belts are cheaper and easier to transport than conventional tires.

Because of the carcass design and structure, the sidewall doesn’t deflect as much as a conventional tire, minimizing sidewall damage. The unit delivers a larger footprint for enhanced traction on any surface, he says, and because the separate tread and carcass dissipate heat better than conventional tires, overall tire life is improved.

One other advantage of the two-piece system is that it allows Goodyear to custom compound tread belts to a variety of service conditions and/or customer preferences, something not easily done with conventional tires.

Design Improves Life

The tread belt consists of steel-belts of multi-strand cable wound circumferentially, and a tread that looks like virtually any other haul truck tire. The underside of the tread belt includes raised circumferential bands that interlock with grooves on the carcass.

The spiral wound belt cable restricts outside diameter growth, which results in a longer, more uniform footprint, with less pressure for enhanced flotation and lateral stability. Plus it reduces belt edge shear strain, and enhanced durability, Goodyear claims.

The carcass is similar in construction to a conventional OTR tire, with its own steel belts. No adhesive or mechanical lock holds the two elements together. The carcass is partially deflated to allow the tread belt to slip on; as the carcass is re-inflated it expands to meet the tread belt, holding it securely in place, Goodyear says.

In the more than two years of field evaluations, only two carcasses were lost to damage, claims Walker. "But we haven’t worn a carcass out yet," he says.

Three tread patterns have been tested in field evaluations, "but we’ll probably introduce just one pattern to start with," says Walker. The tread belts can be retreaded, and Goodyear has talked to some retreaders, though no one’s attempted it as yet.

Dealers wanting to offer the Two-Piece Assembly must undergo an extensive certified training program covering sales and field service, he says, and the product is only being offered to authorized Goodyear dealers.