Correct Replacement Size for a 7.75-15 Trailer Tire

Updated 06/05/2019 | Published 06/04/2019

Products Featured in This Question

Karrier ST205/75R15 Radial Trailer Tire - Load Range C

(2229)

$109.44

Karrier ST205/75R15 KR03 Radial Trailer Tire - Load Range D

(2229)

$120.08

Question:

I see an explanation for a modern tire size in your threads that is as follows.... The closest modern tire size to the 7.75-15 would be ST205/75-15, available in bias ply load range B as part # AM1ST91 or load range C as part # AM1ST92. It is also available in radial, load range C as part # AM10244. The ST205/75-15 would about the same diameter and 1/2 inch wider than the 7.75-15. Someone is telling me to use this size..... 215/75 r14 × 1 will it be ok or should I look for the above and is the ply range B or C equivalent to 6 or 7? THANK YOU

asked by: Ethney M

Expert Reply:

The 215/75-14 tire you referenced will not work in place of a 7.75-15 tire because they use a different diameter wheel. Therefore, the 205/75-15 would indeed be your best option for replacement. This size would have the closest dimensions to the old 7.75-15 tire you have now which means there would be little to no chance for fit issues.

For a 205/75-15, I recommend the Karrier ST205/75R15 Radial Trailer Tire part # AM10244 for load range c (1,820 lbs per tire) or part # AM10245 for load range d (2,150 lbs per tire). These tires have a radial construction which means they will be better for highway use than a bias ply. The ply rating is no long used so as long as the total weight of the trailer is under the total weight capacity of your tires you will be good to go.

expert reply by: Conner L