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Can of Worms.. LT vs ST 13K trailer

Nutinelse2do
Explorer
Explorer
Morning,

Will try to keep this as simple as possible.

Doing the investigation of new tires. I was completely convinced to go with either Duravis or XPS LT tires . My rig GVWR is 12.7 loaded with 6k axles. So by the book I should be using ST tires which have a carrying capacity of 3500 each vs 3000 on LT.

Several questions.

If my rig has a GVWV of 12,700 why are there only 6k axles?

Does keystone subtract the pin weight from what the tires/axles should carry?

Would I be over stressing LT tires with the weight above?

Also concerned with what I have read about 65 mph and overheating on ST's

I know all the discussion on LT vs ST, but the above questions are my main concern. As always I am probably over thinking this, but we still have 9 months to go and it occupies my time.. 🙂
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Dennis_M_M
Explorer
Explorer
Another vote for XPS Ribs
'99 Volvo VNL610 - 425 HP Volvo; Super 10 Spd
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JIMNLIN
Explorer
Explorer
op asks wrote:
Several questions.

If my rig has a GVWV of 12,700 why are there only 6k axles?

Does keystone subtract the pin weight from what the tires/axles should carry?

You answered your question although its not just Keystone that does this. Using 20 percent of 12700 GVWR has a 2570 lb pin wight or 10160 lbs on two axles or 2540 lbs per tire. The LT E at 3042 times four gives your trailer over 12000 lbs of tire capacity for a nice reserve capacity.

Would I be over stressing LT tires with the weight above?

Absolutely not. We've used LT E at 3042 lbs capacity on 3/4 ton trucks 6000-6084 rear axles and 6k trailer axles for decades.

Using LT tires isn't a new thing out here in the real world of light trucking and trailers.
We used 14"/15" and 16" truck tires (LT) and P (passenger) tires for years before the tire industry gave us the infamous ST tire.
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers

'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides

wandering1
Explorer
Explorer
If my rig has a GVWV of 12,700 why are there only 6k axles?
Because that is all you need. Subtract the pin weight from the GVWR.

Would I be over stressing LT tires with the weight above?
It depends entirely on the weight capacity of the tire. Read the sidewall.

Also concerned with what I have read about 65 mph and overheating on ST's. ST or LT, do not run the tires faster than the max speed on the sidewall. Higher speeds than what the tire is rated for will cause the tire to overheat which will damage the tire.
HR

NC_Hauler
Explorer
Explorer
I will make it close to unanimous...go with the Michelin XPS Ribs....as also stated earlier, 15% to 20% of whatever your 5er weighs loaded is pin weight which is carried by your truck, not by your 5th wheels axle's or tires....
Jim & Kathy, (Boxers, Buddy & Sheba)
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Splashers3
Explorer
Explorer
I totally agree with BO Plenty....

XPX RIBS and sleep well at night!
2017 GMC 3500 Sierra Denali, C/C, D/A, DRW, w/40gal Aux tank, 18K B&W Patriot.
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rseymour21
Explorer
Explorer
x how ever many that is for the LT
I increase my wheel size from 15" to 16" just so I could pick LT! I have not been sorry!
2003 F250 7.3L
2008 Cougar 292RK

Allworth
Explorer II
Explorer II
Find some CAT scales and run it across hooked up to the truck. You will have a little over 10K on the axles. With a GVWR of 13,800 I have 10,540 loaded for extended travel.

LT

LT

LT

I like the B.F. Goodrich Commercial TA. Seems to be a good balance of price and wear. (LT245/75R16 LRE)
Formerly posting as "littleblackdog"
Martha, Allen, & Blackjack
2006 Chevy 3500 D/A LB SRW, RVND 7710
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B_O__Plenty
Explorer II
Explorer II
Totally agree on using LT tires. My Ribs have been trouble free. There will NEVER be another ST tire on any rig of mine...I don't care what you ST lovers say. I've compared them side by side. ST is like a bicycle tire in comparison.

B.O.
Former Ram/Cummins owner
2015 Silverado 3500 D/A DRW
Yup I'm a fanboy!
2016 Cedar Creek 36CKTS

FastEagle
Explorer
Explorer
Nutinelse2do wrote:
Morning,

Will try to keep this as simple as possible.

Doing the investigation of new tires. I was completely convinced to go with either Duravis or XPS LT tires . My rig GVWR is 12.7 loaded with 6k axles. So by the book I should be using ST tires which have a carrying capacity of 3500 each vs 3000 on LT.

Several questions.

If my rig has a GVWV of 12,700 why are there only 6k axles?

Because the trailer's hitch weight is subtracted from the GVW and added to the tow vehicle.

Does keystone subtract the pin weight from what the tires/axles should carry? YES!

Would I be over stressing LT tires with the weight above? Probably not.

Also concerned with what I have read about 65 mph and overheating on ST's. I know all the discussion on LT vs ST, but the above questions are my main concern. As always I am probably over thinking this, but we still have 9 months to go and it occupies my time.. 🙂


When replacing ST tires that are listed on your trailer's certification label you are going to have to take on the responsibility for the change. Unless, the vehicle manufacturer will recommend another tire design or a retailer will take on the responsibility for you and do so with the bill of sale. Industry standards will not support the use of replacement tires with less load capacity than the OE tires. Tire manufacturers are very reluctant to warranty replacement tires they consider a misapplication.


FastEagle

Me_Again
Explorer III
Explorer III
rhagfo wrote:
Many will state ST are designed to take the sidewall stress of the tandem axle.


ST tires are the dirty little secret of trailering. There is nothing much special about them other than they dodge normal tire industry standard with inflated rating based on speed restrictions and the fact that they kill few people. And they are cheap, really cheap to the trailer manufacturers!

They are highly marketed by an small number of manufactures and importers. And they were troublesome way before manufacturing was moved to china.

Those with 6K axles and under are lucky in that there are many LT tires available that will give much better service, with the two the OP noted being two of the best.

Install them, trailer on and don't look back. They will roll down the road easier and be more stable. The closed outer rib on the XPS Rib and R250 does not grub in tight maneuvers. Go look at the trailer tires at a truck stop and see what the tread pattern looks like. Hint, it will not look like the current ST tires, but will resemble the Rib, R250 and GY G614 trailer tire.

Chris
2021 F150 2.7 Ecoboost - Summer Home 2017 Bighorn 3575el. Can Am Spyder RT-L Chrome, Kawasaki KRX1000. Retired and enjoying it! RIP DW 07-05-2021

Francesca_Knowl
Explorer
Explorer
rhagfo wrote:
There are no ST's in big trucks.

It's true that the descriptor "ST" isn't used on big truck tires, but there ARE bigrig tires designated by their makers as for use on trailer axles alone.

See "trailer Tires" section at This Michelin Longhaul truck tire page
" Not every mind that wanders is lost. " With apologies to J.R.R. Tolkien

rhagfo
Explorer III
Explorer III
Nutinelse2do wrote:
Morning,

Will try to keep this as simple as possible.

Doing the investigation of new tires. I was completely convinced to go with either Duravis or XPS LT tires . My rig GVWR is 12.7 loaded with 6k axles. So by the book I should be using ST tires which have a carrying capacity of 3500 each vs 3000 on LT.

Several questions.

If my rig has a GVWV of 12,700 why are there only 6k axles?

Does keystone subtract the pin weight from what the tires/axles should carry?

Would I be over stressing LT tires with the weight above?

Also concerned with what I have read about 65 mph and overheating on ST's

I know all the discussion on LT vs ST, but the above questions are my main concern. As always I am probably over thinking this, but we still have 9 months to go and it occupies my time.. 🙂


I would rather run LT's closer to their Max load capacity, than ST tires with a larger margin. They cost more for a reason. Many will state ST are designed to take the sidewall stress of the tandem axle. Well commercial HDT run the same tires on all axles, drivers and trailers. There are no ST's in big trucks.
Russ & Paula the Beagle Belle.
2016 Ram Laramie 3500 Aisin DRW 4X4 Long bed.
2005 Copper Canyon 293 FWSLS, 32' GVWR 12,360#

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MrVan
Explorer
Explorer
The answer is LT tires only! No and No to ST tires of any type or size.

Campinfan
Explorer III
Explorer III
Your rig has 6K axles because they Mfg does not include the weight that will be on the pin or the landing gear.
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