Yet Another Tire and Wheel Question - Page 2

Nankipoo · 02-04-2021, 07:31 PM

Quote:

Originally Posted by sourdough

Why wouldn't you go back in the recommended size and go up a load range?

I would like to keep the same height tire I have now. TV and 5'er are level with the tires that's on it now. I would go up a load range which would be LRF. The Carlisle tires you referenced are LRG. Carlisle does make a ST235/85/16 in a F. It's called Radial Trail HD. Don't know anything about these tires.

**sourdough** · 02-04-2021, 07:36 PM

I've had the Radial Trail HD tires in a different size - they were very good tires, no problems and I would recommend them.

DBinSD · 02-07-2021, 08:15 AM

FWIW - I went with Goodyear Endurance ST255/85R16 Radial Trailer Tire - Load Range E
(4080# @ 80psi) mainly due to a SPEED rating of (N) or 87MPH.

Heat (speed) build up is what causes most trailer blow outs.

The above mentioned Sailun tires carry a speed rating of (L) and is in the low 70's if memory serves correct.

The Goodyear Endurance carries the same (4080#) load at a higher / FASTER speeds meaning more heat tolerance.

jadatis · 02-07-2021, 08:34 AM

If you go for G load the maxload for same 150kmph/92mph, mayby even 160kmph/ 99mph, is 3750 lbs, for your 6000GAWR with 10% reserve 98 psi needed, so below the max of rimms.

Your 3040 lbs maxload now only gives poor reserve,

Then extra reserve because you probable maxspeed used is 75mph, and maxload of tires is calculated for 92 or 99 mph.

If you go for ST for instance Endurance, the 4400 lbs maxload is given for 65mph, and 98 psi would also be needed to give the same reserves as the P or Q speedrated LT tires you have now.
So I would not step down to a ST tire, in this case its a downgrade, though it looks like much better, because of the 4400 lbs maxload given.

I found out the system they use, and rule of tumb is for every 10kmph/6.5mph different , 1 Loadindexstep different, higher speed》 lower loadindex, lower speed 》 higher loadindex.
If you use that on your sise , 6 LI steps lower for the LT Q speedrated then the ST between J and K speedrated, Maxload 4400 is 132 loadindex, 3750 lbs is loadindex 126, is 6 LI steps lower.

DBinSD · 02-07-2021, 08:47 AM

Quote:

Originally Posted by jadatis

If you go for G load the maxload for same 150kmph/92mph, mayby even 160kmph/ 99mph, is 3750 lbs, for your 6000GAWR with 10% reserve 98 psi needed, so below the max of rimms.
.

The Sailun (G) rated tire has a max speed rating of (L) or...75 mph. Unless they are listing it wrong

Size ST235 / 80R16 129 / 125L G
Brand SAILUN
Section width 235 Millimeters
Rim width 9.25 inches
load capacity 4080 Pounds
Tread depth 10 32nds
Tire aspect ratio 80.0
Hoop size 16 inches
Speed rating: L.
Load index: 129.0.
Load capacity: 4080.
Section width: 235.0.

Case580c · 02-07-2021, 01:27 PM

Another option is Boar Wheel. We upgraded tires and wheels. Worth a look.

CWtheMan · 02-07-2021, 01:47 PM

Quote:

Originally Posted by Nankipoo

A TO3BM is the closest wheel I can find on the Sendel site. If this is my wheel in an 8 lug 16x6, the highest pressure is 94 PSI. The Sailun tires don't come in an LRF. Since they can't be run at lower pressures, I guess the Sailuns are out. Now I'm back to square one on what tires to buy. This crap is complicated.

Here is a pic of my wheel.

Does the 94 PSI wheel have a zero offset? I find it strange they would make a wheel that will not support the maximum - 95 PSI - pressure rating for LRF tires. A trailer manufacturer would not mount a LRF tire on a 94 PSI wheel.

CWtheMan · 02-07-2021, 01:50 PM

Quote:

Originally Posted by Nankipoo

I would like to keep the same height tire I have now. TV and 5'er are level with the tires that's on it now. I would go up a load range which would be LRF. The Carlisle tires you referenced are LRG. Carlisle does make a ST235/85/16 in a F. It's called Radial Trail HD. Don't know anything about these tires.

Did you verify the Original Equipment tire size on your trailer's certification label?

**JRTJH** · 02-07-2021, 01:56 PM

Quote:

Originally Posted by DBinSD

The Sailun (G) rated tire has a max speed rating of (L) or...75 mph. Unless they are listing it wrong

Size ST235 / 80R16 129 / 125L G
Brand SAILUN
Section width 235 Millimeters
Rim width 9.25 inches
load capacity 4080 Pounds
Tread depth 10 32nds
Tire aspect ratio 80.0
Hoop size 16 inches
Speed rating: L.
Load index: 129.0.
Load capacity: 4080.
Section width: 235.0.

I'd be curious to know how the two tires you listed "stack up against each other"...

I'd wonder if the heat buildup in a 14 ply tire with a speed rating of L operated at 110 PSI travelling 70MPH is greater than the heat buildup in a 10 ply tire with a speed rating of N operated at 80 PSI and travelling at the same 70MPH. One is operated 5 MPH under max speed and the other is operated at 22MPH under it's max speed rating.

Calculating sidewall flex in a G rated tire carrying "X" load at 110 PSI vs the sidewall flex in a E rated tire carrying that same load at 80 PSI, both travelling at 70 MPH under similar road/temperature conditions... I'd wonder if there's any advantage to one tire over the other in that environment....

I wonder why Keystone opted for LRG tires over LRE Endurance tires other than cost and possibly diameter ???

Maybe one of our tire experts can offer some insight ???

Nankipoo · 02-07-2021, 08:19 PM

I'm still watching this thread closely. As of now I'm thinking I'd better go back to school and re-take chemistry and physics to be able to buy tires for this rig. Lol.

**sourdough** · 02-07-2021, 08:50 PM

Lots of "extraneous" stuff seems to happen on a tire thread. Separate the wheat from the chaff.

CWtheMan · 02-08-2021, 12:52 AM

Valid answers for the OPs questions cannot be given until the Original Equipment tire size described on the vehicle certification label is provided.

The procedure for selecting replacement tires is the same for all vehicles built to satisfy FMVSS standards. They must provide a load capacity equal to or greater than what the OE tires provided.

ST tires must have a speed letter molded into the tire's sidewall. Without one, the tire is a 65 MPH tire.

Northofu1 · 02-08-2021, 02:34 AM

235/80R 16E is the original size according to RVUSA.

Jnich17 · 02-08-2021, 04:32 AM

Manufacturers subtract the 20% tongue load rating from the GVWR and then it falls into axle rating. tires from Manufacturer are always minimal rating just to meet these specs. My new 2021 Avalanche 382FL has the G rated tires with 5 year warrantee. We will see!

Nankipoo · 02-08-2021, 05:09 AM

Quote:

Originally Posted by Northofu1

235/80R 16E is the original size according to RVUSA.

Sorry for the confusion. When I posted this on my phone it showed the pics I posted of the stickers on the side in camper. When I got on PC last night I realized the pics were not there. Original tires were 235/80R/16E

See if it works this time.

jadatis · 02-08-2021, 05:29 AM

So the OEM are 235/80R16 ST, and the tires you have on now are LT 235/85R16.
In my reaction I used the tires 85 , and looked back in list of Goodyear to compair.
The OEM sise was not given in that list in the right loadrange.
So I could not compare the difference befween ST and LT.
Still its better to upgrade to LT in F- or G- load, but F is not available.
The E-load ST only has given higher maxload, because given for 65mph. In theory OK when driving not faster then 65mph, but a bit more speed, or load on tire, or inacurate to high measured pressure, or combinations of that, and tire overheats. This only has to happen once, and beginning damage is done by little crackes . It can take up to 3 years, before the cracks tear that much further, that tire blows or treath-seperation, and then the moment of overheating is long forgotten, and tirebrand is blamed.

That is why you have to build in maximum reserve without bumping, to cover the inacuracies, and higher speed.
Can still be that in the end you only yust have enaugh for the speed and load used.

CWtheMan · 02-08-2021, 06:32 AM

Quote:

Originally Posted by Nankipoo

Sorry for the confusion. When I posted this on my phone it showed the pics I posted of the stickers on the side in camper. When I got on PC last night I realized the pics were not there. Original tires were 235/80R/16E

See if it works this time.

Now we’re getting somewhere. The OE tires that came on your trailer (ST235/80R16) provided more than 15% in load capacity reserves depending on brand. That’s more than adequate for your certified axles.

ST235/80R16 LRF tires will provide more than 30% in load capacity reserves at 95 PSI. IMO, anything more than that will act just like solid rubber tires and could be very damaging to your trailer’s chasse and framing.

Tireman9 · 02-08-2021, 01:45 PM

Quote:

Originally Posted by Nankipoo

Why would they put (LRE) on the sticker if they don't even meet the minimum requirements?

Load Range E is talking about the inflation pressure not the load capacity.
ST type tires have higher load capacity then LT type even when the dimensions and Load range are the same. This is because ST type tire Load charts are calculated based on 65 mph max speed and trailer only ( no passengers) vehicle.

What does your Certification Sticker show for type tire? ST or LT?

**JRTJH** · 02-08-2021, 05:02 PM

Quote:

Originally Posted by Nankipoo

Why would they put (LRE) on the sticker if they don't even meet the minimum requirements?

The 235/80R16 LRE tires do meet more than the minimum requirements.

Here's how it's figured:

Trailer GVW 13000
Pin weight 1985
Axle weight 11015

Tire weight 11015/4=2753.75 each

The "calculated weight on each of your tires is 2754 pounds. There will be some differences in wheel weights on the trailer, on any trailer, but typically they are less than 10%, so you're talking a range of wheel weights from about 2500-2900. But for calculations, consider each wheel as sharing an equal amount of the axle weight.

The capacity of the 235/80R16 LRE tire @80PSI is 3520. That's a reserve capacity of 3520x4=14080 which is 766 pounds over the anticipated weight on each tire at maximum GVW. That's a reserve capacity of 766 pounds (per tire), which is 28% "excess capacity".

If you install 235/85R16 LRE rated at 3640 per tire, you'd have 14560 total capacity. With that same 11015 pounds on the axles, the reserve would be 3545 which is 886 per tire or 32% excess.

Going to the 235/75R16 LRF tires would give you 3960 per tire, for an reserve capacity of 1206 per tire which is 44% excess.

I'm not sure why you'd even consider LRG tires at 110 PSI on a trailer that light. I'd suspect that you would have some significant issues with trailer ride quality and possibly frame/wall/cabinet damage from the harsh ride.

**sourdough** · 02-08-2021, 05:44 PM

For me it's pretty simple, probably brought on by the many years of tires being undersized for an RV IMO. I use the GVW of the trailer, add 10% and get the load range that fits that. I do not subscribe to the notion that you remove the pin/tongue weight from the anticipated weight the tires need to carry for many reasons. JMO and others will vary.

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