I have a 1994 Spartan Elite boat trailer. It has Loadstar A78x13ST original? tires on it, and I want to replace them. Since A78x13 is no longer made, what would be an equivalent size I could use? There isnt a lot of room between the fender and the tire, so I wouldnt want to go any larger in circumference or width. Thank You.
asked by: michael r
The replacement size for the A78x13ST original tire is the ST175/80-13. The overall diameter is 24.1 inches and the overall width is 7 inches. You might want to measure on your trailer to make sure you have the clearance for the ST175/80-13 size.
The Loadstar ST175/80D13 Bias Trailer Tire with 13 inch White Wheel, # AM3S030, you have referenced is a bias tire on a 13 X 4-1/2 white wheel. The tire is a Load Range B, which means it is a 4-ply rated and has a maximum load of 1,100 lbs. at 35 psi.
You will want to check the maximum load on the A78x13ST tire you have to make sure you get the correct load rating for your trailer.
The ST175/80x13 size is available in a bias tire with a load range of B (1,100 lbs. at 35 psi), load range C (1,360 lbs. at 50 psi) and load range D (1,610 lbs. at 65 psi).
It also comes in a radial tire with a load range of C and a load range of D.
The difference in the bias tire and the radial tire is that the radial tire will give you a smoother ride than the bias tire and better stability with the newer, continuous rib tread design.
I am including links to the page of radial tires available in the ST175/80x13 size and a page of bias tires in that size. Also, I am including links to a couple of FAQ pages that will describe tire sizing and frequently asked tire questions.