Trailers tires are defined by the symbol "ST" which stands for Trailer Tires, "P" stands for passenger vehicles and "LT" stands for light duty trucks and SUV's. "ST" tires are made specifically for use on trailers and differ considerably from automotive tires. If you own a trailer you should be using only tires that where manufactured specifically for trailers with the symbol "ST"on the side walls.
The main benefit of using "ST" tires is it has about 10 percent more load capacity then an equivalent "LT" tire and about 40 percent more then a "P" tire when filled to the proper psi rating. The "ST" mold of the tire is designed to fit and accommodate trailer rims which are most often narrower then "P" and "LT" rims. This provides an advantage since the tires are narrower and designed to carry the necessary payload that the tire is rated for.
Another important advantage is the sidewalls provide a much stiffer and stronger ply especially in its lower section. This definitely reduces sidewall flexing, helping it to track straighter and diminish the risk of trailer sway and risk sidewall blowouts.
Two Types of "ST" Bias or Radials
Radial tires have since pretty much swept the tire industry. The main difference between Bias and Radials are the plies, in Radials the plies run perpendicularly, Bias have a crisscrossing cords of polyester or nylon on the sidewalls as well as on the tread.
So which tire is the better Radials or Bias, each one has a specific advantage over each other, when deciding which one will suit your needs the best, you should talk to a tire specialist so he can choose the correct tire to fit your trailing needs. The Bias tire would certainly have an advantage with payload and speed and Radial will have an advantage when it comes to tread wear.
Bias tire tread wear life is approximately 18,000 miles or 28,800 klms and the Radials would have a tread wear life of approximately 40,000 miles or 64,000 klms. This is under a perfect world; you may get more miles or klms depends on many conditions, weather, wheel bearings and how you maintain your trailer and how much your payload is on normal use.
Make sure you always check your psi on your "ST" tires no different then "LT" or "P" tires, under inflated tires will wear much quicker. As an example of an under inflated tire by 20 percent will cut 25 percent of the tires life expectation. so make sure you check your tires psi at least once a week.
Overloading your trailer is a huge cause of tire failure. You should always know the actual way that you are towing. This would included the boat, trailer, fuel in the boat and all other types of gear you will be carrying. When you are overloaded with additional carrying weight the overloaded tire will produce an inordinate amount of heat, which can cause tire degradation or a possible blowout.
RJ PICK UP SERVICE
241A Main Street North
Uxbridge, Ontario, L9P 1C3