Recommendation to Replace B78-13ST Tires on Boat Trailer

Updated 04/10/2019 | Published 04/09/2019

Question:

Hello, I have an old boat trailer that I converted to use to for a floating dock. I pull the dock out of a lake during winter. I only pull the trailer about 1/4 mile from my cabin to the boat launch and back. I put all of about 1 mile on it every year! No open road traveling. The dock rests on the trailer through the winter. Id estimate the dock weighs about 1000 lbs. The current tires are B78-13ST. One of them blew out last fall on the trip out of the lake. Can I put your Kenda ST175/80R13 tire on the existing wheels? Or would you suggest getting the whole set with new tire and wheel? I am looking at the Karrier ST175/80R13 tires that you have listed. Current wheels are 5 on 4-1/2. Pilot diameter is about 3 3/16 inch which I believe corresponds to the 3.19inch listed in the specs. Thank you

asked by: Larry B

Expert Reply:

The B78-13ST tire size you currently have on your trailer is equivalent to an ST175/80-13 so you can make this swap without an issue using your existing wheels. Since you don't actually pull the trailer much at all and any towing you do is on rougher/off-road terrain I recommend going with a bias ply tire. A bias tire has a stiffer sidewall than a radial which just makes it the better option for this type of application.

The Kenda # AM1ST51 should work perfectly as it features a maximum load of 1,360 pounds at 50 psi giving you a combined load capacity of 2,720 pounds which sounds like more than enough for the loaded dock.

I have attached a short video review that you can check out as well.

expert reply by: Chris R