15 " tires for towable trailer in dual axel

[Cumminsfan]

Cliffy, I agree for the most part. I too have a big cushion on weight with my ST GY Marathons and keep my speed below 65 mph. I did however have one that developed a bulging area on the tread. Luckily I saw it one morning while walking around doing a visual check over before we hit the road for the rest of the trip. I swapped the bulging tire out for the spare. Went to Les Schwab and bought a cheapo to replace the bulging one and used it as a new spare. I've ran GY Marathons on my last two trailers and have had good luck until this summer when that one tire developed the bulge. I was a GY fan up until then but will switch to the Maxxis Bravo as mentioned by TL259.
Current tires have around 11,000 in 3 seasons.

[timetogo]

From the Tire Rack site:

"During the second half of 2015, a Service Description was branded on each Marathon Radial's sidewall, identifying the tire's Load Index and L-Speed Rating (75 mph - 120 kmh)."

I don't find a material and workmanship warranty for Marathons. Should be at least 5 years.

[Cliffy]

Are there ST tires that are radials?
Or are the Marathon Radials not listed as ST tires?
I didn't think STs were ever radials.
Back to school

[Cliffy]

Marathon STs for 75 psi carry some restrictions according to the Service Bulletin sent out by GY. Normally they are 65 mph tires.
It requires 10 more psi be added to the max inflation pressure but does not give any additional load carrying capacity. Attention needs to be placed on the wheel and valve stem to allow the extra psi.
Clip of SB below:


Special Trailer (“ST”) Tires
Goodyear Marathon trailer tires are widely used in a variety of towable trailer applications and are designed and branded as “ST” (Special Trailer) tires.
• Goodyear Marathon Special Trailer tires, with the “ST” size designation, are speed rated at 65 MPH (105 km/h) under normal inflation and load conditions.
• This speed rating is based on Tire and Rim Association loads and inflation pressures for ST trailer tires without a service description for speeds up through 65 mph. (ref: TRA 2013 Year Book)
• If Goodyear tires, with the ST designation, are used at speeds between 66 and 75 mph (106 km/h and 120 km/h), we recommend the cold inflation pressure be increased by 10 psi (70 kPa) above the recommended pressure based on the trailer placard for normal inflation and load conditions. You should also consult your trailer manufacturer’s Owner’s Manual for maximum operating speed recommendations for the trailer.
o Increasing the inflation pressure by 10 psi (70 kPa) does not provide any additional load carrying capacity.
o Do not exceed the maximum pressure for the wheel or the valve.
o If the maximum pressure for the wheel or valve prohibits the increase of inflation pressure, then the 65 mph rated speed must observed as the maximum speed.
o It may be necessary to dismount the tire from the wheel to determine the maximum rated inflation for the wheel and valve. *
*Details about wheel and valve inspection:
a) If the rated (maximum allowable) inflation pressure is not visible on the wheel, consult the wheel or trailer manufacturer.
b) Tubeless snap-in type valves, depending on the type valve, are rated for a maximum inflation pressure of 65 or 80 psi for nominal 0.453” diameter valve holes. If a higher cold inflation pressure is used, a clamp-in valve such as TR416S valve (200 psi maximum inflation) must be installed.

[JIMNLIN]

Originally Posted by russtman

I am towing a Jayco Jayflight 26 rls and need to put new tires on it. Any recommendations for new tires in 15 inch with high rating and high ply ???
Why the need for such a high ply rating on that small 8500 GVWR TT ?? just curious

Rating D and above to G and ply 10 to 14 --- any info is appreciated.

The benefit of a E tire (80 psi) comes at those higher pressures.

First and foremost for safety.... are your present 15" wheels rated for 80 psi .

Forget about a 14 ply load G tire at 110 psi for that size trailer. Not a good idea. Trailers unlike a truck can be over tired.

I assume your trailer Jayco Jayflight RLS has 15" D load range tires. Most 15" D tires are a ST225/75R-15 D load range radial at 2540 lbs capacity. Four tires = 10160 lb capacity.

Jayco web shows your 26rls has a 8500 GVWR. The ST225/75-15 tire has more than enough reserve capacity for that small TT.

Tire replacement is pretty simple out here in the real world. The only legal (roadside) issue for the trailer owner is the tires capacity has to meet or exceed the vehicles GAWRs regardless of what capacity the trailer mfg installed.


Industry tire engineer/experts like Tireman9 RV Tire Safety: Reserve Load and experienced trailer owners (rv and non rv) know a 10-15 percent reserve capacity is a good idea for long term reliability.

I would stick with the a ST D tire and keep them at 65 psi 24/7. Starlite and PJ trailers are high on Provider ST radials for their heavy trailers. They should work great on a RV trailer.

If you do a lot of interstate miles per year as many of us do and the ST tires don't stand up then the best upgrade is a LT225/75-16 E at 2680 lbs per tire for that size trailer. And of course check for proper top and side clearance issues for your particular trailer.
One size don't fit all.