Tire Choice

Thanks to everyone who offered advice and info. I certainly received an education in trailer tires and wheels. Although I did not want to put the OEM GY Marathon ST235/80/16E back on the trailer, in the end I did. I am in a travel status in a small town and had quite a time being able to get a replacement. Hopefully, things will workout. The tires I an replacing are well over three years old and I don't know their history as I am the 2nd owner.

Thanks again

FastEagle wrote:

Me Again wrote:


Michelin is doing that with the 215/75R17.5 XTA which is being installed OEM on 5th wheels. It carries a 100KM speed rating(62MPH), 120 inflation and 4805 lb load rating. Michelin is saying the speed can be increased above 62MPH by reducing the max load below 4805 lbs. This drives one posted crazy, however it is according to industry guidelines/standards. There are charts for some tires that allow extreme loads at very low speeds.

Quoted from the Michelin Truck Tire Service Manual. Bottom of the right column on page nine of the reference.

"The Tire And Rim Association, Inc (TRA) permit operating a 65 MPH rated tire at higher speeds with a reduced load and increased inflation. No such permission is granted by TRA for tires with speed ratings below 65 MPH."

Michelin Ref

FastEagle

Did Michelin respond to your letter about this and the XTA?

Chris

My CC had LT's placarded right from the factory although when I bought it one year old, there were ST's onboard. CC stated it was a function of what they had available during the build at that time. I readily swapped out the 'China Bombs' with Cooper SM II Lt's.

My 2005 Cardinal with factory sized LT235/85/16 tires has been pulled all over the USA. I had Kelly tires for the first 6 years and after much research went with Firestone Transforce about two years ago. I have never had a tire problem with this rig.

I do check my tires often when on the road and maintain 80 psi when cold. After researching tires, I decided it was going to be michelins or the transforce. I got a better deal on the transforce. I have the same size tire of Michelins on my dually.

Me Again wrote:


Michelin is doing that with the 215/75R17.5 XTA which is being installed OEM on 5th wheels. It carries a 100KM speed rating(62MPH), 120 inflation and 4805 lb load rating. Michelin is saying the speed can be increased above 62MPH by reducing the max load below 4805 lbs. This drives one posted crazy, however it is according to industry guidelines/standards. There are charts for some tires that allow extreme loads at very low speeds.

Quoted from the Michelin Truck Tire Service Manual. Bottom of the right column on page nine of the reference.

"The Tire And Rim Association, Inc (TRA) permit operating a 65 MPH rated tire at higher speeds with a reduced load and increased inflation. No such permission is granted by TRA for tires with speed ratings below 65 MPH."

Michelin Ref

FastEagle

CapriRacer wrote:


I don't think inflation pressure would have any affect on those wheels. Those cracks are no where near the flange, which is where inflation pressure would have the greatest effect.

So while it is likely a good idea to replace those wheels - or at least monitor them - I don't think they preclude the use of higher inflation pressures.

Here is the info on the wheels on that year/model Cardinal:'

16x6 8-6.5 0 3580 Clear Coat / Polished

Wheels are rated to 3580 pounds each. A heavier stiffer tire like the G614 is only going to stress the spokes of these wheels more. I am sure a call to Tredit will have them advising against installing G614 tires on them.

These larger Cardinals in that year range were under tired and wheeled. Fix it right with new 16" wheels and G614's or 17.5 rims and tires. Cardinal is now using Tredit's T09 8 spoke wheels rated to 3750 on all of their trailers(thanks to input from the Cardinal club). Even those that come with GY Marathon's are coming OEM with the higher rated wheels, and G614's are a factory option available(again from input from the Cardinal Club).

On another note, I am seeing that you are nibbling around the corners of the fact that tire pressure, speed and load ratings can be manipulated allowing one parameter to offset another.

Michelin is doing that with the 215/75R17.5 XTA which is being installed OEM on 5th wheels. It carries a 100KM speed rating(62MPH), 120 inflation and 4805 lb load rating. Michelin is saying the speed can be increased above 62MPH by reducing the max load below 4805 lbs. This drives one poster crazy, however it is according to industry guidelines/standards. There are charts for some tires that allow extreme loads at very low speeds.

This is why I have long felt the Michelin XPS Rib(and BS R250) when used at RV speeds(75 and below, Michelin list that speed for RV use) is more capable than it's 3042 rating and/or can be used safely right up to it's max rating without concern.



Guess what, this is how the ST tires get a higher rating!!!
Chris

Me Again wrote:
OP's Cardinal has wheels that are only rated to 80 pounds inflation and have a history of cracking.......

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Chris

I don't think inflation pressure would have any affect on those wheels. Those cracks are no where near the flange, which is where inflation pressure would have the greatest effect.

So while it is likely a good idea to replace those wheels - or at least monitor them - I don't think they preclude the use of higher inflation pressures.

In my TT days, I had issues with USA made 15" D load Marathons. The tires were loaded to 90% capacity (2200#), but still within the specs from Jayco. After the 3rd one failed, I went to 16" rims and Michelin XPS Ribs, E load. What a difference in handling, durability and piece of mind. I finally decided running the Marathons so close to their limit made for short tire life.

usnret wrote:
I have had a tire issue of late and am thinking of replacing all four fiver tires. The Cardinal now has ST235/80R/16 Goodyear Marathon tires (made in China). My question is, can I replace the current tires with a LT235/80R/16 or an equivalent tire. If you have any replacement tire recommendations please let me know.

Thanks

I feel confident that your trailer's certification label will list each GAWR at 6840#. Which, not surprisingly, is the maximum load capacity of your OE tires. Therefore, you're in a catch 22 situation. Stick with the ST235/80R16E and find some with 3520# of load capacity at 80 psi.......Or, see if your OE rims are rated for 3640# at 80 psi which is what the ST235/85R16E is rated for.......Or, move up to the ST235/85R16F rated at 3960# at 95 psi........Or, consider the 7000# axle workhorse LT235/85R16G rated at 3750# at 110 psi.

Clearances between tires must also be considered along with rim selections.

Good Luck.

FastEagle

I already posted about his wheels not being rated for LRG tires. Plus they have been cracking. The Cardinal Club forum has lots of info on these wheels. That is where the pictures came from that I posted.

It is either stay with ST tires and the associated problems or spend 2-3k to fix it right. Chris