Retreading has been present in the tire industry since the 1910s. Its success is not a surprise, as recapped tires are considerably cheaper than new ones and just as good to go. Buses, trucks and aircraft rarely use new tires.
Retreaded tires are in essence used tires that were inspected, repaired and which receive a new tread. Given a whole new life, these tires are much cheaper than new ones. The whole process, also called recapping, is more environment-friendly than manufacturing.
Most commercial trucks use retreaded tires.
Retreading is a careful process which begins with selecting a proper tire to retread, which in recappers’ jargon is called the “casing”. Casings are inspected both visually and with equipment to find any damage to the carcass that still can be fixed, bearing in mind that the internal wiring will have to endure one more lifetime. If the tire is accepted, the old tread must first be removed. To do that, a tire is mounted on a machine that will carefully tear the remaining tread.
What happens then depends on the type of recapping process. Precure retreading is a method that attaches an already prepared strip of tread to a clean casing. Before placing the tread, an adhesive must be placed to a casing. The tire is then put in a pressure chamber.
Mold cure method involves applying a thick layer of raw rubber to the casing. The tire is then put in a heated tire mold that vulcanizes the rubber and stamps the tread and the sidewall. This method is used less often and resembles producing a new tire, but it eliminates the problem that precure retreading creates with a place where two ends of the new tread meet.
Retreading is environment-friendly. The process uses less material than required to manufacture a new tire. This is also responsible for lower price of these tires. Recappers sometimes check the tires to find problems that overlooked in the manufacturing process. If it comes at the cost of safety, may be more difficult to judge, but since most public and private service vehicles, including buses, trucks, as well as commercial and military aircraft all use retreads, it is logical to assume that retreading lowers the price and is more environment-friendly without having an impact on safety.
Which tires can be retreaded?
Retreading passenger car tires is still practiced in Europe, but in the United States,
new passenger car tires are not much more expensive than recapped ones.
In the 1950s, when most passenger car tires used multi-plied bias structure and had higher sidewalls, retreading passenger car tires was a normal practice. However, trying to find regenerated tires for a modern sedan or a coupe may be a challenge in the United States. Though not impossible, as there are still some retreaded SUV and light 4x4 tires around, you would have to do some browsing to find a place that sells them. Recappers in Europe still commonly regenerate passenger car tires. In America, however, new passenger car tires are not that much more expensive than retreaded ones would be.
Retreading usually concerns commercial truck tires, many of which have been manufactured with the idea of retreading in mind. Heavy duty tires have a different structure, which makes the process easier. Retreading, as the very name suggests, changes the tread, so the wiring inside has to endure more than one lifetime – this is why retreading passenger car tires, with much less durable internal structure, is less effective than doing so with heavy duty tires. Commercial truck tires are also quite expensive, so buying retreaded tires for a fleet can save thousands of dollars, while such tires do not have to be worse than the original ones, albeit almost always the main reason to buy them is their price.
Motorcycle tires can also be retreaded, but the international community approaches the very idea with caution. Two wheels, open cockpit and high speed equals putting your life at much higher risk than in a car. Most people will rather find a nice offer for Pirelli or Dunlop motorcycle tires and pay between 200 and 300 dollars per set than to use a technology that is generally not trusted.
Retreading aircraft tires is a very common practice. Having to endure sharp braking at speeds exceeding 200 mph on a runway, rubber from tires is peeled off like skin of a carrot. It takes just between 150 and 300 landings to tear an aircraft tire to a point when it has to be replaced. Both commercial planes and military jets use retreaded tires.
It is possible to retread agricultural and industrial tires. Off-road tires can also be regenerated, including heavy mud terrain treads, although it may be difficult to find a facility that can do this.