Why Only 6 Ply Tires?

[robertwhite]

Why is it that every new utility 18' trailer I have found only comes with 6 ply tires? Are dealers so cheap that they can't order 8 ply (minimum) tires when they order their trailers? Even with only 3500lb axles, the carry weight could easily be around 3 ton, which flattens out the little 6 ply tires. 8 ply only cost a few bucks more at time of order.

What gives?

 

[brain55]

I would blame customers more concerned about price than features or durability. Most people looking at light weight utility trailers don't know the difference between 6 and 8 ply tires all they know is the dealer down the street has what they consider the same trailer for $50 cheaper.

 

[jeffsw6]

If you are not happy with what is on the lot, don't buy off the lot!

 

[vtsnowedin]

Nothing new here. Back twenty years ago I went with my brother to Kansas to pick up a stack of three new trailers to bring back to the dealer in Vt. Not long after leaving Kansas we had our first flat. Cheapest thing to do was to take a tire off the top trailer for a spare. By the time we got to VT the top trailer had four flat tires on it. Know what you need and what they are offering and how much difference that makes in the price you can afford to pay.

 

[robertwhite]

With your example of the 3500 pound axle, that's 1750 pounds per tire. That can be handled by many P rated 4 ply tires. So the 6 ply can be more than enough.

Yeah, ummmmmmm. That load of 1750 includes the trailer weight (say 1200lbs or so). Take that 1200 pounds and subtract it from the 7K and you basically have a 3 ton load rating. Now everyone knows that axles are rated WAY under what they can hold, so I should have no problem when I load 3 ton of stone on my trailer. Guess what? The 6 ply tires were pancakes, and that is a problem.

 

[whistlepig]

Yeah, ummmmmmm. That load of 1750 includes the trailer weight (say 1200lbs or so). Take that 1200 pounds and subtract it from the 7K and you basically have a 3 ton load rating. Now everyone knows that axles are rated WAY under what they can hold, so I should have no problem when I load 3 ton of stone on my trailer. Guess what? The 6 ply tires were pancakes, and that is a problem.

The axles are rated for what they are rated. And no, not everyone knows that the axles are rated way under what they can hold. It just doesn't work that way.

 

[jeffsw6]

If you want to put 3 tons of stone on your trailer, buy the right kind of tires. And trailer, for that matter. Maybe your trailer won't fall apart, but if you get into an accident and a person is injured, you can bet some ambulance-chasing lawyer will investigate whether or not you were trailering safely, and if you weren't, they will use it against you. $0.02.

 

[kneedeep]

I have been looking at trailers to buy and most 'Utility Trailers are just that! Not made to haul big loads even with 3500# axles. They are just for hauling the riding mower and stuff that wan't fit in a pickup. They are built mostly out of angle with the cheapest tires that match the axle rating. Most come with a mesh tailgate a small tractor will crush. UTILITY!!
If you want something that will take a load, you have to step up to the "Equipment Trailers" with channel tongues and better tires. They start at 7K# GVWR (same as your utility) but will cost much more.
A 3500# axle will fail if it is subjected to more than that much weight in time. Tires have to be aired to maximum pressure also.
You might have bought less trailer than what you really need. A new set of tires may also solve your problem.

 

[schmism]

so I should have no problem when I load 3 ton of stone on my trailer. Guess what? The 6 ply tires were pancakes, and that is a problem.

you need more than 40 psi of air in them next time :thumbsup: read the sidewall, put what it says they need. (likely 50-60lbs)

 

[jeffsw6]

They are just for hauling the riding mower and stuff that wan't fit in a pickup.

I don't think they are quite that bad. Again, it's about buying the right kind of trailer (and ramp/gate, etc.) for the job.

 

[kneedeep]

I don't think they are quite that bad. Again, it's about buying the right kind of trailer (and ramp/gate, etc.) for the job.

I humbly disagree.
Anything with 2 axles is probably 7K rated minimum regardless of how the trailer is built. That is the rating for the 2 3500# axles and not the tires or trailer. Smaller axles are for singles with 13 and 14 inch tires. Those cheap trailers are not well built for hauling maximun axle loads. Thats why they are so cheap. Most SCUT will haul on them but they are real easy to overload. Most have no engineering to back them up.
Buyer beware! Do your homework before buying a trailer, a little research could save a lot of trouble down the road.

PS
Everything I have looked at carries at least 8 ply ST tires on 7K# axles. I have spec 18' and 20' trailers that weigh up to 3000#. If the estimated weight is 1200# why is it so much lighter? Smaller steel maybe??

There are a LOT of cheap trailers out there and you do get what you pay for.

 

[JIGBUILDER]

Trailer manufacturers choose tires per 571 FMVSS's which say in part ......the sum of the maximum load ratings of the tires fitted to an axle shall be not less than the gross axle weight rating (GAWR) of the axle system as specified on the vehicle's certification label required by 49 CFR part 567.

The manufacturer isn't required to use a specific size or load range tire. Just capacity. Most 7k gvwr trailers with 3500 lb axles come with C load range tires in a 225/75-15" @ 2150 lbs of capacity at 50 psi or even 205/75-15 @ 1820 lbs of capacity. Plenty of tire for a 3500 lb axle.

IMO the 8 ply rated D tire has 2540 lbs of capacity at 65 psi requires a wheel upgrade. The trailer manufacturers know some folks will overload their trailers if they use over rated tires and wheels.

If you need 8 ply tires you need the heavier rated wheels/suspension/axles and trailer frame for the job.

 

[slowzuki]

Ditto.