Trailer Wheel/Tire Recommendation for Replacing Size 185/80R13 on Tandem Trailer Weiging 6400 lb

Published 10/23/2018

Products Featured in This Question

Karrier ST175/80R13 Radial Trailer Tire - Load Range D

(2229)

$104.94

Karrier ST205/75R14 Radial Trailer Tire w/ 14" White Spoke Wheel - 5 on 4-1/2 - Load Range D

(1484)

$189.84

Question:

Need new boat trailer tires. Originals ST 185 80 R13 load range C. Tandem Trailer weight 1200 lbs, boat/motor 4200, total 6400 lbs. Original tires support 1480 #s x 4 x .88 = 5210 lbs. Correct? Your ST 185 80 D13 8 ply supports 1710 x 4 x .88 = 6019 #s. Correct? Appears I need the extra support. No long trips with boat. Mainly marina to water several times a summer and 40 miles round trip once a year for motor service. Trailer/boat sit 5 months during winter on concrete. Problem with bias is heats more than radials. If bias sits gets flatter than radials and get bumping when pull till tire warms. Correct? I think the greater bias load capacity and stronger side walls may provide longer lasting and maybe outweighs the flatness of bias with prolonged sitting and bumping down road till tire warms and rounds out . Thats all I have read. What is your advice? Any other thoughts on weight excess problem. I do not carry extra luggage in boat when transporting. Put that all in vehicle. Thanks

asked by: Lee T

Expert Reply:

You need a tire and wheel setup with at least 6,400 lb of capacity since that's how much your boat and trailer weighs together so I would not recommend anything in the 13 inch wheel size as nothing in that size will be rated high enough. The next size up that has the capacity you'd need would be the 205/75-14 in Load Range D which would have capacity of 2,200 lb at 75 psi.

For a white wheel and tire in that size and Load Range we have the part # AM32161 which has a 5 on 4-1/2 inch bolt pattern and would work well. This is a radial too so it will be the preferred style you want and will hold it's shape better.

expert reply by: Jameson C