Selecting Replacement Special Trailer Tires in Size ST185/80-13 for 5th Wheel Trailer

Question:

Hi I have a 19ft 5th wheel camper. It calls for 185/80-13 Tires. I cant find a radial tire in that size. Would I be ok with bias? Looking for 4 new tires with rim. Thank you

asked by: Matt

Expert Reply:

In your smaller 5th wheel tire size ST185/80-13 we do offer only bias ply tires. These are available as tires only or as pre-mounted wheel-tire combinations with the popular 5-on-4-1/2 wheel bolt pattern. You can see all such items on the linked page.

You can certainly switch from radial to bias ply tires, but you just cannot mix tire types, sizes or load ranges. You can find helpful trailer tire information in the linked articles.

What you want to do is ensure that you choose tires that can safely handle the gross weight of the trailer. Find the trailer's GVWR on its main sticker, then divide this maximum weight by the number of tires on the trailer. This will tell you how much weight each tire needs to be able to handle.

For example, part # AM3S333 is a Load Range D bias tire on a white 5-on-4-1/2 wheel that can handle 1710-lbs at its rated pressure of 65-psi. It is also rated for highway speeds up to 81-mph.

The best way to protect any trailer tire is to ensure that you ALWAYS 1) inflate to the required psi pressure shown on the tire sidewall; 2) observe the tire/wheel weight capacity; and 3) observe the maximum rated speed.

It is also recommended to protect all the tires during storage periods by use of covers like # 290-3954.