Upgrading 20.5x8-10 Tires on Pontoon Boat Trailer to Higher Load Capacity Tires

Question

Question:

I know this is a recurring topic, but can you provide some advice on replacing/upgrading my pontoon trailer wheels/tires? I have 20.5 8-10 tires on galvanized wheels that are 5 on 5.5. They are load rating F. Boat and trailer weight is under 3,000 lbs and the #84 single axle is 3,500 lb rated. Is there a 13 inch or other size wheel/tire combination that I could upgrade to which would allow a similar load rating with higher speed rating? My assumption is that a 13 inch wheel would “run cooler” on the highway, is this correct? Alternatively, I see that you recommend 205/65-10 tires as a replacement for what I have. Will this tire share the same rim that I currently use? Since 10 inch 5 on 5.5 galvanized wheels are difficult to find, would I consider switching the hubs to 5 on 4.5 or another configuration in order to have more ion in options going forward? If so, are there considerations in hub ion?

asked by: Bill H

1

Helpful Expert Reply:

The modern equivalent to the 20.5x8.0-10 size tires on your pontoon trailer is the 205/65-10 size, which would fit your existing wheels without issue. The highest rated trailer tire we have available in this size is the Kenda Loadstar K399 Bias # AM1HP56, which features a maximum load of 1,650 pounds at 90 psi. This would give you a combined load of 3,300 for a nice safety margin with your trailer that weighs under 3,000 pounds when loaded. This particular tire does also have an excellent speed rating of 87 mph.

With regards to switching to a larger (and thus higher rated) tire and wheel combo and its effect on temperature, your assumption is correct for a number of reasons. A tire that's larger in diameter would have fewer revolutions on the road and would thus run a bit cooler. Since the larger tire will also have a higher capacity, its sidewalls also wouldn't flex as much which would in turn further prevent the tire from heating up as quickly. The tire itself would also be able to withstand more heat before the potential for failure increases.

As you mentioned in your question, a 5 on 5-1/2 inch bolt pattern isn't too common so if you wanted to upgrade in size to say a 13 inch tire and wheel you would need to also replace the hubs.

A much more common bolt pattern is 5 on 4-1/2 inches like with the etrailer.com # AKHD-545-35-EZ-K for a hub and drum assembly. This will fit the #84 spindles on your trailer. This pattern would give you much greater flexibility in upgrading to a larger tire and wheel if desired.

When upgrading to a larger size tire you just need to make sure you have the available wheel well and trailer frame clearance.

For a 13 inch tire and wheel combo that will work well after switching out your hubs I recommend the Kenda Karrier ST175/80R13 Radial Trailer Tire with 13" Galvanized Wheel # AM31994. This particular tire will have an overall diameter/height of 24 inches (compared to 20.5 inches for what you currently have) and a width of 6.9 inches (which is actually smaller than your current width of 8.1 inches). Since this is a radial ply tire it will also run cooler than your existing bias units because of how the cords are constructed. This tire features a 1,610 pound maximum load at 65 psi and a speed rating of 81 mph.

expert reply by: Chris R

1

Answer 1

Sorry to hear your tire heated up and came apart. Special trailer tires are typically rated to operate at a maximum speed of 65 mph and should always be inflated to their maximum air pressure stated on the tire. I would certainly go with a radial…

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Answer 2

If you want to go to the next size up from a 5.30-12 tire you will need to look at 13 inch wheels and tires ST175/80-13. For a wheel and tire combo with 5 on 4-1/2 bolt pattern and radial tire use #AM31985. This tire will be 7 inches wide and 24.1…

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Answer 3

Your current 20.5x8x10 size trailer tires have an overall diameter of just over 20-inches. The modern metric designation for this size is 205/65-10, an example of which is #AM3H490. The tire size you want to switch to, 175/80-13, has an overall…

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Answer 4

The Dexter "8-248" is a hub assembly for 3,500 lb axles that uses an L68149 inner bearing and a L44649 outer bearing. This hub assembly was offered in both 5 on 4-1/2" and 5 on 4-3/4" bolt patterns therefore you…

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Answer 5

I went out to the warehouse and pulled trailer hub #84545BX. The outer diameter of the center bore is 2.59 inches. I used a set of digital calipers to take the measurement.

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Answer 6

Assuming that you're looking for an idler hub with a 5 on 5-1/2 inch bolt pattern, the Dexter #84545BX hub you'd looked at is what you'd need for your 3500 lb axle.

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Answer 7

The Karrier ST175/80R13 Radial Trailer Tire with 13" Galvanized Wheel item #AM31994 are not balanced nor do they need to be.

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Answer 8

To determine the size of the hub assembly you need to purchase you have to determine which bearings are in the old assembly. If the old assembly has L44649 inner bearings, you would use the hub you chose #8-258-5UC1. If the inner bearings are…

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Answer 9

A trailer's weight carrying capacity is a function of all the parts used to construct it. These include the trailer's frame, axle, suspension, hubs, wheels and tires. Each of these individual components will have its own weight…

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Answer 10

The Dexter hub part number prefix 8-201 could refer to many items and includes many possible weight capacities. So the best way to go is to pull one hub, remove the bearings and find their stamped part numbers. If you happen to know the…

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Answer 11

It sounds like you are needing to replace the hub and drum assemblies on your trailer. The B12E-22 number you mentioned in your question does indeed correspond to an electric brake assembly, specifically the etrailer.com #AKEBRK-6R for the Right…

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Answer 12

Karrier and Loadstar are two different brand names used by Kenda. There's no difference in quality or function between the two brand names. For a ST175/80-13 Radial trailer tire in load range D, I'd recommend part #AM10210 if…

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