Trailer Tires

mabynack wrote:
Thanks for all the input. After comparing LTs and G-load rated STs, I've found that no matter which one I choose, it's going to cost me over a $1000. The Michelins mentioned in one post are going to run me $370 each. The Goodyear STs in load range G are going to run over $300, and will require new rims rated for the increased tire pressure.

I doubt you will need new rims. Use the load/inflation chart for the new tire.

I went from E to G tires and ran 85psi on 80 psi rims with no issues. When up sizing add 5psi to the charts recommended pressure. All per GY tech support.

amxpress wrote:
I installed a set of 16" Maxxis on my 11,600# Columbus. Mounted and balanced for less than $600. I would have installed Michelin LT Ribs, but could not afford $1300 +.
My Maxxis were much heavier than the China bombs they replaced, the sidewalls were much thicker, too. They're made in Thailand, not China. I also ran Maxxis on my Jayco back in 2007, no problems with them, either.

I find these statements interesting. Especially with a nice truck and RV in the pic.

"I would have installed Michelin LT Ribs, but could not afford $1300 +"

Quoted from The Tire Rack: incidently, its also a good place to shop for tires.
Key info: ST tires are only rated to 65 MPH.

There are differences in the driving requirements between the tires on your trailer and those on the car or light truck you used to tow it. Therefore there are distinct differences between the way trailer tires and tow vehicle tires are engineered.

Your tow vehicle is a leader, which means traction is a key focus in the design of its tires. Traction allows your tow vehicle to accelerate down the road, turn around the corner and brake to a stop. Another important consideration is tow vehicle tires are designed for ride comfort, which is achieved in part by allowing their sidewalls to flex.

Your trailer is a follower, which often makes tire sidewall flexing a negative. Sidewall flexing on trailers, especially those with a high center of gravity (enclosed/travel trailers) or that carry heavy loads, is a primary cause of trailer sway. Typical passenger radial tires with flexible sidewalls can accentuate trailer sway problems. The stiffer sidewalls and higher operating pressures common with Special Trailer (ST) designated tires help reduce trailer sway.

Also consider that Special Trailer (ST), as well as Light Truck (LT) tires are fully rated for trailer applications. This means ST- and LT-sized tires can carry the full weight rating branded on the sidewalls when used on a trailer.

However when P-metric or Euro-metric tires are used on a trailer, the load capacity branded on the sidewalls must be reduced by 9%. This means P-metric or Euro-metric tires with a maximum branded load rating of 1,874 lbs. for use on a car is only rated to carry 1,705 lbs. when used on a trailer.

Comparing the load capacities of a pair of tires of the same dimensions fitted to a single axle trailer, ST225/75R15 Load Range C-sized tires inflated to their maximum of 50 psi provide 4,300 lbs. of load capacity, where P225/75R15 Standard Load-sized tires inflated to their maximum of 35 psi would be limited to 3,410 lbs. of load capacity, a total reduction of 890 pounds.

Trailers will be more stable and pull better on tires designed specifically for trailer use. Since Special Trailer (ST) tires are constructed with heavier duty materials, they are tougher than typical passenger vehicle tires. This is a plus because trailer suspension systems are generally stiffer and less sophisticated than automotive suspension systems.

Special Trailer (ST) Tire Speed Ratings

Industry standards dictate tires with the ST designation are speed rated to 65 MPH (104 km/h) under normal inflation and load conditions.

However Goodyear Marathon and Power King Towmax STR tires featuring the ST size designation may be used at speeds between 66 and 75 mph (106 and 121 km/h) by increasing their cold inflation pressure by 10 psi (69 kPa) above the recommended pressure for the rated maximum load.

mabynack wrote:

MCSloan wrote:
Most RV tire problem are caused because they don't have enough reserve capacity for the load on them.IMHO you need at least 20% extra capacity.If your hauling a heavy 5er bite the bullet and go with the 17.5 wheels and commercial tires.It will be cheaper and safer in the long run not fixing blown tires on the side of the road and constantly buying new tires. Also repairing damage to your rig from exploding tires.

That's my thought on this, too. My RV weighs 14,000 lbs. The tires are rated for 3500 lbs each. There's no reserve capacity.

Aprox 20 percent of that 14,000 is on the truck as pin weight. So you have around 11,200 on the axles. A high quality LT235/85R16E is your best bet. I noted the two best above. There is NO ST tire in the same league. Chris

If you notice the trailer industry (all types) don't use a wide base tire like a 265/75 tire for several reasons.

A 265/75 tire has a 8 to 8.5" wide tread which adds tremendous stress to the tire internally and bearings/wheels/axle U bolts and spring hangers as it side scrubs around corners.

I've never heard of a 8" wide trailer wheel with a zero offset. You sure don't want to mount a 265/75 tire on a narrow 6"-6.5" wide load baring std trailer wheel. Doing so balloons the tire tread.

Sounds like your trailer has 6k axle with LT235/85-16 E tires at 3042 lbs capacity.

As Me Again posted above you the Michelin XPS Ribs or the Bridgestone R250 both being a commercial grade all steel ply carcass LT tire work best on trailers with 6k axle.

Now if your wheels are rated to 3500 lbs capacity then the G614 or the commercial grade all steel ply carcass Sailun S637 tires would work fine.

How many people are using 265/75/16 /E I have 14000 lbs axles on my trailer and am running right at the max load of the 235/85/16/E tires that are on the trailer. (3040lbs)
The 265's have a load rating of 3407 lbs . A lot cheaper than GY 614. I have scaled the trailer and I'm running just a little under 12000 loaded. And NO I'm not planning on upgrading the rims to 17.5

SH wrote:

mabynack wrote:
I checked the rating on the rims on my 14,000 lb fifth wheel last night and they're rated for 3045 lbs. I couldn't find a pressure rating on them, so I'm still not sure if I can go to a load range G tire without changing the rims.

Don't know if this is a "normal" situation or not...a 14K GVWR coach on four wheels rated for a total of 12,180 lbs. I do know that my 15K rig has wheels rated to 15K (3750) for what its worth!

I ended up with new 614's only because of the weight rating. The Bridgestone is a great tire...had them on my truck!

AT a 14K GVWR the GAWR is below 12K. Trailer most likely has 6K axles and the ones in the mid 2000's came with Load Range D ST235/80R16D tires. An all steel ply Rib or R250 is an excellent upgrade to a reliable tire for this trailer.

Chris

SH wrote:

mabynack wrote:
I checked the rating on the rims on my 14,000 lb fifth wheel last night and they're rated for 3045 lbs. I couldn't find a pressure rating on them, so I'm still not sure if I can go to a load range G tire without changing the rims.

Don't know if this is a "normal" situation or not...a 14K GVWR coach on four wheels rated for a total of 12,180 lbs. I do know that my 15K rig has wheels rated to 15K (3750) for what its worth!

I ended up with new 614's only because of the weight rating. The Bridgestone is a great tire...had them on my truck!

AT a 14K GVWR the GAWR is below 12K. Trailer most likely has 6K axles and the ones in the mid 2000's came with Load Range D ST235/80R16D tires. An all steel ply Rib or R250 is an excellent upgrade to a reliable tire for this trailer.

Chris

MCSloan wrote:
Most RV tire problem are caused because they don't have enough reserve capacity for the load on them.IMHO you need at least 20% extra capacity.If your hauling a heavy 5er bite the bullet and go with the 17.5 wheels and commercial tires.It will be cheaper and safer in the long run not fixing blown tires on the side of the road and constantly buying new tires. Also repairing damage to your rig from exploding tires.

That's my thought on this, too. My RV weighs 14,000 lbs. The tires are rated for 3500 lbs each. There's no reserve capacity.

Me Again wrote:

mabynack wrote:
I checked the rating on the rims on my 14,000 lb fifth wheel last night and they're rated for 3045 lbs. I couldn't find a pressure rating on them, so I'm still not sure if I can go to a load range G tire without changing the rims.

OK I am going to explain to you how to have many miles of happy trailering.

Measure center to center of your axles!

Grater than 33 inches - Install LT235/85R16E Bridgestone Duravis R250's

Less than 33 inches - Install LT245/75R16E Bridgestone Duravis R250's.



If you want to spend a couple hundred more to for no good reason then install Michelin XPS RIBs.

Compare the tread pattern to the high end GY G614 trailer tire.



Do it and don't look back!!!!!

Your trailer depending on year may have come OEM with load range D ST tires rated to 3000 pounds, so a LT tire rated to 3042 exceeds that, and it a MUCH better tire!

Chris

Mine came with Goodyear E rated 235/85R16s. They did pretty well for the first four years.