Bias vs. Radial
Some ST trailer tires are bias-ply tires, which have crisscrossing cords of polyester and/or nylon. Trailer tires are also offered in radial construction. Radial trailer tires feature plies that run perpendicularly across the tire, with belts (some made of steel) running under the tread.
• Bias-ply trailer tires are recommended for tough, rugged performance and side wall puncture resistance, such as trailers used for construction, agriculture and some marine applications.
• Radial tires are recommended when smooth ride, tread wear, heat and extended tire life are important considerations. Depending upon the trailer duty cycle (storage time/vs. actual time in use under load) the mileage expectation of radial trailer tire can be from 5,000 to 12,000 miles. However, under well maintained conditions, proper inflation and correct loads, considerably higher miles have been reported.
Trailers are used for one purpose, transporting loads. A major cause of trailer tire failure is overloading. It’s important to know the actual load of the payload under tow, including all the toys, equipment, gas, gear, water and the trailer itself. An overloaded tire will produce excessive heat in the sidewall and tread which can quickly cause tire degradation or blowout. Excessive heat is the number one cause of trailer tire failure. The problem increases in the sunbelt areas where roadway surface temperatures are well above normal conditions.
All tires are manufactured to handle specific load limits, but in towing trailers, loads are the single greatest concern. Review the tire sidewall information and the vehicle’s owner’s manual for vehicle load limits and proper tire inflation. Never exceed the maximum vehicle load rating stamped on the tire sidewall or the maximum vehicle load rating whichever is less. If possible, try to distribute the load evenly across all tires so that no single fire is overloaded. Tongue weight, tongue height and especially load leveling hitches must be set properly to avoid overloading the trailer tires.
Discuss the specific trailer uses to select the ST Tire that is load rated for the situation.
• All tires must be identical in size for the tires to properly manage the weight of the trailer.
• The combined capacity of the tires must equal or exceed the Gross Vehicle Weight (GVW) of the axle.
• The combined capacity of all of the tires should exceed the loaded trailer weight by 20 percent.
• If a tire fails on a tandem axle trailer, replace both tires on that side.
• If the tires are replaced with tires of a larger diameter, the tongue height may need to be adjusted to maintain proper weight distribution.