Increasing Wheel/Tire Size on Carry-On Utility Trailer

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Question:

My Carry-On utility trailer has 4.80-12 size tires on it. Wheel configuration is 5 lug 4.5. Was considering replacing original setup with AM 31985. Im a bit confused. I measured the diameter of the wheels/rims, which is 13 inches. So, Im not sure if I have a 12inch or 13inch wheel. If it is 12, would there be enough clearance to accommodate the 13inch rim? I have at least 3inch all around from tire to fender. Any insight would be appreciated!

asked by: Roger

0

Expert Reply:

You do indeed have a 12 inch rim. When you measure the diameter of the wheel, you'll need to measure the diameter of he wheel where the tire bead meets the wheel. I've provided you a cutaway diagram of a wheel showing where the measurement would be taken. Given the tire size, you have a 12 inch rim.

There are a few things you'd need to check before going with the larger 13 inch wheel w/ 175/80-13 tire. The 175/80-13 tire is approximately 3-1/2 inches larger in diameter, which would bring the tire 1-3/4 inches closer to the fender than it is already. We like to see a minimum of 3-4 inches of clearance with the trailer fully loaded. The 175/80-13 is also about 2 inches wider than your current tires, so you'll also need additional clearance to the inside of the tire.

Given the amount of fender clearance you have, I'd recommend staying with your current tire size. If your current tires are worn, and you're looking for a replacement wheel/tire combo, I'd recommend the Kenda # AM30660 which is a 4.80-12 Load Range C tire on a 12x4 inch rim. If you click the provided link, you can see our Trailer Tire FAQ article, which I hope you'll find helpful.

expert reply by: Mike L

0

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Kevan

5/23/2020

I'm curious as to why a 15 inch tire wouldn't work on a 2000 lb axle. I dont doubt this, but would like to understand the principle behind it. I have a 2000 lb axle and was considering an axle flip and a larger wheel so I could increase my highway speeds a little.

Chris R.

5/26/2020

Assuming you have the wheel well and frame clearance figured out, the main issue with trying to go up to 15" wheels is the hub size that is used on a 2,000 pound axle. Typically 2,000 pound hubs are compatible with, at the largest, a 14" wheel. This is because they simply don't provide enough surface area for bigger rims - and this creates the potential for the wheel to be knocked loose on the road (it might happen when you run over a curb but could also happen from a large pot hole, sudden swerving, etc). The wheel is just too large to work with the smaller hubs on this size axle.

Kevan

5/26/2020

@ChrisR That makes perfect sense. Thanks for helping me understand the physics/mechanical principles behind it all.

Chris R.

5/28/2020

@Kevan No problem at all. Please don't hesitate to reach back out with any other questions that come up.

See All (4) Replies to Kevan ∨

Jeff

7/31/2020

I'm researching a similar project, installing 15 steel wheels with AT tires onto the Carry-On 4x6 utility trailer. I would like to: - increase the clearance with an axle flip kit, after relocating/raising the fenders (which kit would you recommend?) - decrease the "bounce" (empty) with better leaf springs (recommendations?) - install the 15" wheels, with a different axle to accommodate them (again, recommendations?). What size/max width tires would you recommend with this? Thanks for any info you can provide.

Jon G.

8/10/2020

I'd check out the Timbren Axle-Less axles because they use a different type of suspension that is a little more advanced than the classic leaf springs, they don't used a standard axle so ground clearance is increased, and you can get ones that even have a lift. Check out the attached link to choose one with the correct weight rating. If you want to go with a standard axle that will work, but you'll need to find what your hub-face and spring-center measurements are, plus you're going to need to install a suspension enhancement because simply getting heavier leaf springs will just make your trailer ride more rigid.

Helpful Links

dept-pg-trailer_axles-pm-timbren.aspx

Answer 1

The best thing you can do is switch to a Radial Tire #TT48012C if you do not already have them on your trailer. The radial construction is superior to the bias construction on roadways. The radial tires do not heat up as much as bias tires which…

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Answer 2

If the diameter of your axle was 3 inches the kit part #K71-385-00 would work to allow you to move the springs in relation to the axle. Based on the size of the trailer you'd most likely have a smaller diameter axle like 2-3/8 inch like what the…

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Answer 3

Since your Carry-On 5' x 8' Utility Trailer has a 2000lb GVWR it more than likely has a 2000lb axle and would need a hub that uses either inner and outer bearings #L44643 or #L44649. I know on The 5' x 8' Carry-On Trailer I bought…

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Answer 4

Hey Andy, thanks for reaching out! It sounds like you might have a 4.80-12 tire like the Kenda #AM30620, so to upgrade you can use a 5.30-12 tire, like the Taskmaster Radial Tire #TT53012C which is going to have about a 21-1/2" diameter and…

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Answer 5

We recommend that all trailer tires be inflated to the max psi stated on the sidewall of the tire. If the tire is under inflated, the weight capacity is lowered to an unknown amount for that tire. Although running lower air pressures can improve the…

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Answer 6

Yes, the Kenda Karrier S-Trail ST145/R12 Radial Trailer Tire #AM10140 referenced in your question will fit the same 12 inch wheel with a 4 inch width that your existing 4.80-12 size tires are mounted to. Just note that the ST145/R12 tire will be…

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Answer 7

Hello Mark, thanks for getting in touch. The 145/R12 tires and the 4.80-12 are similar but not exactly the same size. The 4.80-12 tires are 4.9" wide and 20.7" in diameter when fully inflated. The 145/R12 tires are going to be about…

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Answer 8

A 4.80-12 trailer tire and wheel such as the Kenda #AM30630, when inflated will measure 20.7 inches in diameter and have a width of 4.9 inches. A 175/80-13 trailer tire and wheel will measure 24 inches in diameter and have a width of 6.6 inches so…

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Answer 9

I'm pretty confident you have a 1-3/4" round tube axle on your Carry On 5x8 trailer. Having a 2" axle is uncommon and is typically only found with square tube axles, which you don't have on your trailer. While there isn't a…

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Answer 10

The Dexter Trailer Springs Over-Under Conversion Kit part #K71-384-00 CAN be used with slipper springs. However, the process of installing this kit on a trailer with a set of slipper springs is more in depth than installing this kit on a trailer with…

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Answer 11

Trailer tires should be inflated when they are cold and should be inflated to the max psi rating on the sidewall. In your case you would want to run 80 psi. If you don't inflate them to the max psi figure you will lose weight capacity and…

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Answer 12

The closest metric trailer tire size to a 4.80x12 is going to be a 145/80-12. The typical diameter of a 4.80x12 tire is 20.5 inches. On a 145/80-12, it is 21.3 inches. So the metric size will be a little over 1/4 inch taller. Make sure to measure the…

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Increasing Wheel/Tire Size on Carry-On Utility Trailer

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