Tire Blowout Causes for Special Trailer (ST) Tires

Published 08/08/2017

Question:

OK LT 8 ply last 3 to 1 v ST 8 ply. 225-75-15 WHY? Im going broke keeping tires on the 8K flat bed trailer. The only time any tires lasted more than 6K miles was a set of LT225-75 x 15 D load.

asked by: Mark S

Expert Reply:

There are several reasons a tire might blow out. For instance, if a tire is inflated to more or less than its maximum air pressure (which will be listed on the sidewall of the tire) the tires, this can potentially cause tire failure. Inflating tires to a lower air pressure than the maximum reduces the amount of weight that the tire can handle, which can cause the tire to fail if a heavier load is placed on the trailer.

Another possible cause is overloading the tire. It's important not to exceed the maximum listed load, as additional weight will put stress on the tire and can cause it to fail, though it doesn't sound like you are overloading the tires based on the weight and tire specification you mentioned. It's also important to distribute the weight on your trailer so that a disproportionate amount of weight is not causing too much stress to an individual tire.

Your maximum tire speed will also be listed on the tire, so it's important to heed this speed limit (many ST tires are only rated for speeds up to 65 mph). Higher speeds cause heat to build up in the tire, which results in tire fatigue and failure. If you don't already use radial ST tires, I recommend switching to them, as they run cooler than bias tires, and heat is the number one tire killer.

ST tires are usually built with stronger sidewalls than other tire types, so if you are experiencing repeated blowout incidents, then that can indicate that something else is wrong. Assuming you are within the weight capacity of your tires and travel within the tire speed limits, you might check for any unusual tire wear, such as wear only on the inside of the tire or flat spots. It's possible that the axles aren't perfectly aligned with the trailer frame, which can cause the tires to drag slightly while towing. A spindle or axle might be bent, which can cause unusual tire wear, or possibly the spindle nut is torqued too tight, which can cause the bearings and hub to bind and heat up.

I recommend going with a tire like our Westlake ST225/75R15 Radial Trailer Tire - Load Range E, Item # LHWL304. Each tire has a maximum load of 2,830 lbs at 80 psi, so with four trailer tires, you would have a capacity of over 11,000 lbs—more than enough to haul an 8,000 lb trailer. The maximum speed rating for this tire is 75 mph. Westlake tires also come with a 5-year warranty and 2-year complimentary roadside assistance.

expert reply by: Amber S