It is time to put some new tires on some of the trucks in your fleet. After adding up the cost for new tires, you might well ask, “How about retreads?” Typically, quality retreads or recaps cost 30- to 50-percent less than new tires. While not all tires are suitable for retreading, a premium tire with a quality casing can be retreaded three or even four times.

Besides saving money, every tire that is reused means one less tire that does not have to be disposed of. Unfortunately, cast-off tires sometimes wind up in a landfill, or, worse, just abandoned in a field where they can be a breeding ground for mosquitoes, insects, and vermin. Piles of used tires can catch fire, burn at very high temperatures, and tire fires are very hard to extinguish

By far, the biggest use for scrapped tires is as fuel for kilns that make Portland cement or for generating heat and electrical power. Others are turned into road construction materials or recycled in everything from playground mats to mailbox posts. Unfortunately, about a third of tires scrapped are still quite usable for their intended purpose if retreaded or just repaired.

Recycled tires also conserve natural resources, most importantly oil. For example, according to the Tire Retread and Repair Information Bureau (TRIB), manufacturing a new medium truck tire uses about 22 gallons of oil. In contrast, retreading of the same tire consumes only about seven gallons.

Retread Myths

One myth is that retreaded tires are not as safe as new ones. Retreads are definitely as safe, provided a high quality retread is done on a casing that is in good condition and not one that has been damaged.

Retreaded tires are now routinely used on school buses, fire engines, ambulances, trucking fleets, taxis, Postal Service vehicles, military vehicles, and by millions of motorists. Nearly 80 percent of all aircraft tires used in the U.S., both commercial and military, are retreads. They are even used on Air Force One.

According to the Tire Debris Task Force, most of the highway tire debris seen on the road is not from retreads peeling off casings. Rather it is the result of punctures, under-or overinflation, and other road damage, something that can happen to new or recycled tires alike.

Retread Systems

What constitutes a quality retread? Basically, the retreading process bonds new tread to the tire body using a process that is similar to the manufacturing process of new tires. According to the TRIB, there are two systems for retreading a tire: Pre-Cure and Mold Cure. Either system requires the proper combination of time, heat, and pressure to create the vulcanization of the new rubber to the tread area of the tire.

They both produce equally good retreaded tires. Both procedures start with a visual inspection with only the best used tires passing the inspection. Next, high-speed buffing machines remove the proper amount of old rubber while turning the tire to an exact specified diameter and radius.

In the Pre-Cure System, the tread rubber has already been vulcanized with the new tread design. A thin layer of cushion gum is wrapped around the tread and the pre-cured tread is applied. The cushion gum bonds the pre-cured tread to the tire. The tire is then placed in a curing chamber, adhering the pre-cured tread to the tire using a vulcanizing process that is very similar to that used in manufacturing a new tire.

With the Mold Cure System, unvulcanized tread rubber is applied to the buffed tire. The tire is then placed into a rigid mold containing the tread design in the tread area. The mold is heated and the rubber in the tread area vulcanizes and adheres to the tire with the new tread design molded in. This vulcanization process is also similar to that used in new tire construction.

Both processes are followed by a final inspection, and the retread is trimmed to remove excess rubber and painted.

Quality Retreads

There are both federal and state requirements on retreaded tires, California’s being the most stringent. However, the best assurance of getting a high-quality retread is to buy from a reputable, professional retreader that adheres to stringent industry-recommended practices at every step of the retreading process.

Most retread plants in North America are owned, franchised, licensed, or otherwise affiliated with major brand suppliers such as Goodyear UniCircle, Bridgestone, Bandag, and Michelin. Besides providing warranties, these retreaders provide technical assistance on tire selection and use.

The ability to retread a worn tire is not solely a factor of age since condition of the casing is the most important consideration. A tire that sees severe service and receives poor maintenance can get old well before its time and thus may not be retreadable. However, an older tire that has not been overloaded and/or run underinflated and has been regularly maintained can be retreaded several times.

Damage & Repair

If you want to retread a tire you are currently using or one to be used for a trade-in, it is important not to wait until the tires are worn to the point where they are no longer safe before they are retreaded. It is risky to let tires wear below the legal minimum of 2/32 inches or 4/32 inches on front wheels.

Casings unsuitable for retreading are those damaged by under-inflation, overloaded above their rated capacity of tire, or installed inappropriately for the intended application. Also unsuitable are tires mismatched on dualwheel setups or not maintained with attention to proper wheel alignment, balancing, or suspension condition. As a rule of thumb, tire life will decrease 10 percent for every 10 percent it is under-inflated.

What about repairing damaged tires? Companies offering tire repair products say holes up to 3/8th-inch on heavy-duty truck tires can be repaired. Also cuts in the sidewalls of radial truck tires of up to five and 1/8th-inch radically by one-inch axially, or up to one-inch in diameter in the crown area can be safely repaired.

The Right Stuff

Correct repair materials and techniques are required. For instance, outside- in or on-the-wheel repairs are not acceptable. Nail holes should be filled with vulcanizing material to keep the hole from growing, which can cause belt separation, and prevent moisture and contamination from entering the casing. The inner liner should be sealed with the appropriate sealing material.

There are different materials and techniques for bias and radial tires, it is important to use the correct one to the particular tire type. Done properly, repaired sidewalls can be as safe and strong as the remainder of the tire.

Some time ago, the American Retreaders Association (ARA) studied strength of sidewall repairs in radial truck tires. Tires with four-inch-long and 3/4th-inch wide repairs were x-rayed and subjected to increased pressure until bursting. The results showed that when properly repaired, sidewall injuries are equal in strength to the surrounding tire body and quite safe.

In sum, it is worth looking into retreading and repairing tires since quality retreads and repairs cost only a fraction of that of a new tire.