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HIGH TEMP HEAVY HAUL: WILL RETREADS WORK?

Posted: August 1, 2014

Will retreads work for heavy hauling in hot climates?

You could be paying two to three times more than you need to for truck tires if you buy into the misconception that you can only run on new tires if you are hauling heavy loads in hot climates.

The fact of the matter is, retreads perform as well as new tires if you select the correct tread design for the application.

Negative impact

Clearly, heat kills tires; and that is why we spend so much time emphasizing proper air pressure inflation. But heat has the same negative impact on new tires that it has on retreads. If you are hauling a heavy load with under inflated tires, your tires will generate heat. If the under inflation is severe enough, so much heat will be generated that the tires will fail and spread wire-embedded rubber all over the highway.

Although retreads are often blamed for the scrap rubber on the roads, those
“alligators” could just as well be new tires. If it was, in fact, a retread failure, you would probably see the scrap rubber without any wire in it.

Retreaders don’t put wire in the tread rubber they put on a casing. When you see wire in the scrap rubber, as you will in better than 95 percent of the scrap out there, you know you are seeing the belt package from the original tire. You can almost be certain that tire failed because of heat associated with under inflation.

A heavy or deep tread design will also produce additional heat. But that heat will be generated by new tires as well as retreads if the wrong design is selected for a given operation. That is why, at Bandag, we have moved to application specific treads to make sure the trucker or fleet is utilizing the tread design that provides the optimal performance for a given application.

Many factors

In the lab, we have found that there are a number of factors that impact how hot or how cool a tire might run. The compound used and tread depth, as well as the void ratio and void distribution are all factors that impact on the heat that might be generated.

In the industry, we use the term “tan-d” or (tangent delta). Tan-d is a laboratory- measured product that is a predictor of rolling resistance/fuel economy, and can be related to the heat buildup in the tread. It takes energy to compress the tread elements as they go through the footprint.
You can think of the tread elements as springs. When they’re compressed, they store energy. Tan-d is a measure of how much of this stored energy will be converted to heat.

We have been able to determine that different compounds can increase the heat generated by 1 to 2 degrees per 32nd of tread depth, depending on the compound and tread design selected for the tire.

For that reason, it is critical that you have a knowledgeable supplier who can help you make the right choice for your particular application. But it is also important to understand that new tire manufacturers do not have a monopoly on cool running tread compounds or cool running tread designs. Cost effective retreads can provide you with those same cool running compounds and tread designs if you’re using the right product for your application.
When fitted with the correct tread design for trucks operating in hot climates, retreads will deliver the same level of dependability as new tires at a fraction of the cost.

Consider an asphalt hauler in southern California who hauls 340 degree asphalt, in the desert, with ambient temperatures of 115 to 120 degrees.

In business for over 30 years, the owner of the fleet was convinced he could only run on new tires because of the severe heat conditions associated with his operation.

In need of capital to expand his business, he reluctantly took the advice of his tire supplier and tried retreads. With the savings over new tires, he funded his expansion without any loss in the areas of tire reliability and dependability.

We trust with the information you have gained in this column, you too will be able to better utilize your operating budget. Informed tire purchase decisions, made in conjunction with a knowledgeable tire supplier, can help free up budget dollars for other operational needs that can improve your business and return more profit to your bottom-line.

This article was authored by Bandag, Incorporated Research & Development staffers.

Reprinted with permission from Bandag.

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