If you are a regular reader of this column, then you undoubtedly know that I am a strong proponent of retreading. The technology and uniformity that goes into producing a modern retread is unparalleled in the history of tires—and it’s only going to keep improving. Despite the persistence from old-school trucking professionals that retreads are the cause of tire debris on the highways, the data proves that they are just as durable as their new-tire counterparts.
And while the process itself has transformed from manual labor to technology, there are still enough differences from plant to plant to create some measurable separation between the top and the bottom of the list. Machines do the majority of the work in a modern retread manufacturing facility, but the people running the equipment play an important role in the quality of the finished product.
The biggest question that remains is which retread process best suits the needs of the fleet. For lack of a better term, flat precure retreads are the most common because they are economical and can be applied to almost any casing. The rolls of rubber come in various widths with the tread designs already molded in place to accommodate different sizes and profiles, so fleets that run a wide variety of tire brands and sizes are often best suited for flat precure retreading.
Another type of precure retreading is known as a ring tread. Instead of the tread coming in rolls that are cut to fit whatever size casing is being retreaded, it is formed in a ring that is stretched to fit over the casing. The curing process is identical to the flat tread, with the biggest difference being there is no splice where the two ends of the tread come together. Ring treads are also manufactured with a slight contour, or radius, so they fit more naturally to the curved surface of the casing after it is buffed.
Mold cure retreads continue to fascinate me simply because of the precision this particular process requires. After the old tread is buffed away, strips of raw rubber are wound around the casing to an exact diameter and radius. Then it is placed in a segmented mold that imprints the tread design and cures the rubber. When it comes out of the press, it will have the look and appearance of a brand new tire because it is basically manufactured in the same way.
In the old days, each process had its drawbacks. Flat precure retreads could vary in diameter and the splice didn’t always match. But computer buffers and builders solved those problems. Ring treads were only possible on a limited number of sizes and brands, but the manufacturers are now able to offer a wide variety of tread designs that fit almost any tire. And mold cure retreads were even more limited, but the retreaders that are still capable of producing them have found a way to retread most casings.
Selecting the retread process that works best for the fleet depends on a number of factors. It should start with a plant visit so you can see firsthand the level of technology and craftsmanship that goes into the product. Then the tread must be tested in the field so a true cost-per-mile or cost-per-32nd comparison can be established. Price is not the only determining factor when it comes to the performance of each process; each has the potential to save a lot of money or cost a lot of money when the decision is not based on how much mileage is delivered. And while looks can be deceiving, the best-looking retreads are typically the best-performing retreads regardless of how they are cured.
Kevin Rohlwing can be reached at [email protected]
