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Trailer Tire Spare Recommendation with ST185/80R13  


Need spare boat trailer tire. Boat weighs 2,000 lbs - 22 ft center console boat used in salt water hence trailer in and out of salt water. The 4 tires on trailer say ST 185 80R13. I do not see any tires on your website that match those numbers. What should I buy from you? Thanks.


Expert Reply:

As far as size is concerned the part number # AM3S334 that you referenced has a tire that is the same size as what you have. The difference is the D in the size instead of the R that is in your tire size. The D stands for bias-ply tire, whereas R stands for radial.

The main difference between a radial ply and a bias ply tire is how the tire is constructed. The cords inside a bias ply tire run at a 32 degree angle to the direction of travel, and the cords on a radial tire run at a 90 degree angle to the direction of travel, or across the tire from wheel lip to wheel lip.

Normally we strongly recommend that you match all the tires of your trailer with the same construction. However, for a spare situation a bias-ply would work in an emergency. If you can find a radial tire of the same size elsewhere that would honestly be your best option since we do not carry a radial in the size you need.

expert reply by:
Jameson C

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