Magazine for the professional tire industry
Issue link: https://mtd.epubxp.com/i/148910
Service trailer tires ing behind the tow vehicle. A trailer tire loses about a pound of air a month, which adds up to a signifcant amount afer months of storage, according to Gerry. As the tire may not sag due to its stifer sidewalls, a trailer owner needs to check tire infation before starting a trip. Customers also need to be informed that driving an underinflated tire produces excessive heat that could lead to a blowout. Radials or bias-ply? Tom Van Ormer, director of purchasing for the East Bay The KR03 Karrier is Tire Co., a Fresno, Calif.-based Kenda's ST radial tire. wholesaler, exporter and commercial dealer, says his company is now ordering more radials than bias-ply trailer tires. "As we see the market in California, it's about 65% to 70% radials right now." Van Ormer does not believe radials will ever completely replace bias-ply tires. "We feel the trailer tire market has shown a steady rebound from the sharp declines in 2009. We fnd the brands that dominate the original equipment market continue to shine in the afermarket. Radials are starting to dominate, but the popular bias sizes continue to have an important place in the line-up." Te performance of radials has improved so much that consumers are replacing bias with radials, according to Van Ormer. "Te atributes of a good radial passenger tire — beter performance when it comes to heat, speed and long distance — are now the atributes of a good radial trailer tire. Original equipment has gone to radials in most cases." ■ ST vs. P vs. LT How trailer tires are different Passenger tires are not built for the higher load requirements, duty cycles and special demands of trailering, according to Carlisle Transportation Products. The company describes the differences between special trailer (ST), and passenger (P) and light truck (LT) tires: • Polyester cords in an ST tire are bigger than in a comparable P or LT tire. • Steel cords used in ST tires have a larger diameter and greater tensile strength to meet additional load requirements. • ST tire rubber compounds contain chemicals to resist weather and ozone cracking, particularly conditions resulting from extended storage and the unusual duty cycles of trailer tires. • The slightly shallower tread depth of a trailer tire reduces sway and rides cooler, which adds to tire longevity. • ST tires generally offer approximately 10% more load capacity than a similar LT tire and nearly 40% more than a P tire. • ST tires feature stiffer sidewalls, especially in the lower section, which: a. reduce sidewall fexing causing the trailer to track straighter, b. diminish the risk of trailer sway, and c. lessen the risk of sidewall puncture and blowout. Trailer tire facts for your customers • Trailer tires must endure more demanding conditions than passenger or LT tires. • Tread does not indicate when a trailer tire wears out. Because a trailer tire is used less often than a car, age, not mileage, determines when it needs to be replaced. • Overloading is a major cause of trailer tire failure. The actual weight of the load is everything under tow, including gear, food, water, equipment, toys, and the trailer. • Proper air pressure keeps the sidewall stiff for straight tracking behind the tow vehicle. An underinfated trailer tire may not sag due to its stiffer sidewalls. 60 Quik-Link: 800-687-1557 ext. 19123 MTD August 2013