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cummins2014

Utah

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Posted: 06/16/23 08:01am Link  |  Quote  |  Print  |  Notify Moderator

Usually the markings ,weight rating ,inflation etc is marked on the backside of the rim , not sure you have to break it down , should be there , unless you have already looked on the backside .

* This post was edited 06/16/23 08:11am by an administrator/moderator *

JTrac

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Posted: 06/16/23 09:20am Link  |  Quote  |  Print  |  Notify Moderator

cummins2014 wrote:

Usually the markings ,weight rating ,inflation etc is marked on the backside of the rim , not sure you have to break it down , should be there , unless you have already looked on the backside .


I've looked several times and can't find any markings.


JimT
2020 Jayco Pinnacle 32RLTS, 2020 Ford F350, Platinum, 6.7 diesel, 4X4, CCLB, SRW, 12,400 GVWR

JTrac

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Posted: 06/16/23 10:59am Link  |  Quote  |  Print  |  Notify Moderator

I take it back, maybe I did look at some point for the rim capacities but forgot about it. I'm only 5 weeks out from knee replacement but decided I have progressed enough to get down on my creeper and slide under the trailer. I was successful. The rims are rated for 4400 pounds and are 16 X 7. I couldn't find the psi rating but it has to 110 or 120 so good to go with heavier tires.

Michelle.S

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Posted: 06/16/23 12:59pm Link  |  Quote  |  Print  |  Notify Moderator

Just something to remember with higher pressure tires. That pressure is there to keep the tire bead sealed to the rim, if you run too low of pressure you run the risk of rolling the tire off the rim when in a tight turn scrubbing the time on the pavement. If you've ever looked at the tires when someone is jack knifing into a site, you would know what I'm talking about, how distorted they become.


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Cummins12V98

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Posted: 06/16/23 06:27pm Link  |  Quote  |  Print  |  Notify Moderator

JTrac wrote:

CapriRacer wrote:

JTrac wrote:

I've been thinking about changing to a heavier duty tire and I'm considering the Sailun's. My problem is I'm not sure if the wheels on my Pinnacle have the capacity for heavier duty trailer tires. It came with 255/85/r16 Goodyear Endurance. Neither Jayco or Tredit Tire and Wheel, their supplier, could tell me exactly what I have. The wheels are 8 lug and the outside width appears to be about 8 inches. Sailun says their 235/85/r16 S637 needs a rim width of 6.5 inches. Other brands give an acceptable range of rim widths but not Sailun. I would hate to order a set and find they wouldn't work with my wheels. No information is stamped on the outside of the wheels.


Tire engineer here.

Wheels: The best information I have been able to gather is that not only does the government not require a max pressure to be written on wheels, but that wheel manufacturers only consider the max load to be important. I take that to mean that stresses in wheel due to pressure are much smaller than stresses due to the load. As confirmation, I note that when people purpose try to fail a tire by inflating it, the wheel isn't what fails.

Allowable rim width range: It's size dependent, not dependent on the manufacturer (brand). That's because there are tire standardizing organizations and they are the ones who set the range - with the agreement of the tire manufacturers. If you see a spec for one brand, it will be the same if another brand doesn't state otherwise.


Thank you. I have a friend who has a couple of tire shops in our town. I'm going to take a wheel to him and he is going to break it down and see exactly what I have. I'm pretty sure I have a 7 inch wide rim rated by the manufacturer for 110 psi and 4400 pound load capacity. This would match the Sailun's and several other tires I'm considering if that is the case. My total weight for the fifth wheel loaded for a month long trip to the Colorado Rockies is 14,700. My hitch weight is 3120 leaving 11,580 on the axles. I know getting the heavier tires would be overkill and I would have to adjust the inflation accordingly but I have always been one to err on the side of safety.


"E" rated ENDURANCE is more than enough tire for your load.


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Cummins12V98

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Posted: 06/16/23 06:29pm Link  |  Quote  |  Print  |  Notify Moderator

Michelle.S wrote:

Just something to remember with higher pressure tires. That pressure is there to keep the tire bead sealed to the rim, if you run too low of pressure you run the risk of rolling the tire off the rim when in a tight turn scrubbing the time on the pavement. If you've ever looked at the tires when someone is jack knifing into a site, you would know what I'm talking about, how distorted they become.


If your load is within what the weight/inflation chart dictates the tire will perform flawlessly.

Michelle.S

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Posted: 06/16/23 06:54pm Link  |  Quote  |  Print  |  Notify Moderator

It's not the load weight, it's those side stresses. Had a friend that didn't like the hard ride of his car running the normal 35 Lbs Radials, lowered the pressure to give a softer ride. When into a sweeping exit ramp, rolled the tire right off the rim, rim dug into the pavement and he rolled his car.
I'm just offering a suggestion on being careful to not go to low. Some have suggested running a 110 PSI tire as low as 70 PSI.

cummins2014

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Posted: 06/17/23 07:35am Link  |  Quote  |  Print  |  Notify Moderator

JTrac wrote:

I take it back, maybe I did look at some point for the rim capacities but forgot about it. I'm only 5 weeks out from knee replacement but decided I have progressed enough to get down on my creeper and slide under the trailer. I was successful. The rims are rated for 4400 pounds and are 16 X 7. I couldn't find the psi rating but it has to 110 or 120 so good to go with heavier tires.



Thats great, that's where most are marked . Good to go with Sailun , run them 90-95 . I have similar weight ,and I run 95 in mine , have done so for two sets now , no issues .

Cummins12V98

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Posted: 06/17/23 08:37am Link  |  Quote  |  Print  |  Notify Moderator

Michelle.S wrote:

It's not the load weight, it's those side stresses. Had a friend that didn't like the hard ride of his car running the normal 35 Lbs Radials, lowered the pressure to give a softer ride. When into a sweeping exit ramp, rolled the tire right off the rim, rim dug into the pavement and he rolled his car.
I'm just offering a suggestion on being careful to not go to low. Some have suggested running a 110 PSI tire as low as 70 PSI.


It's really simple the more load the more air is needed. Less load the tire has less stress that you are concerned about and so the psi can be lowered to what the chart says with ZERO issues.

Sidewall PSI is what the tire is designed for to carry a certain load. Too many think it says inflate to no matter what.

I run psi base on load, this is exactly why I get more miles and EVEN tread wear than most anyone on here. How many get 65k on a DRW carrying a 6k pin weight plus toolbox and hitch weights 1/2 the miles?

StirCrazy

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Posted: 06/17/23 09:17am Link  |  Quote  |  Print  |  Notify Moderator

blofgren wrote:

StirCrazy wrote:

Let me add to this conversation, if your rv had a GVRW for 12400ish lbs and a pin weight of 2500 would you even go to a load range G tire. I decided to kick this down the road for a few years since I have replaced two tires in the last two years (one at the beginning of last season and one last week) and found a third that I suspect had separated so I took the other two in and got them done this morning. so, rolling down the road the weight on the tires should total around 10000 lbs which a good 10 ply is rated for 3500lbs @ 80psi. 70PSI will give me 3000lbs per tire. So as of right now I have 4 new Hercules Power ST2 tires so I am going to run these for the next season or two and decide exactly what I should go with for a tire. is the Sailun overkill? for this weight. I think for 3000lbs per tire from them I would be running at 65PSI

Steve


Have you weighed your axles to ensure that they are carrying what you think they are? If so, then the Sailun may be overkill. That said, they are a good heavy duty tire with very heavy sidewalls, and with your stated weights they would last a good, long time.

I certainly wouldn't run them at 65 psi if you decide to go with them, but they would probably be fine at 80 psi. You might find that your tire shop will not mount them on 80 psi wheels, however....


ya that's how I know my pin weight was 2800 lbs. not 2000 like the brochure said. going down the road the weight on the axels is about 10000lbs give or take depending how I am loaded have the new set of tires inflated to 70psi which is 3000lbs on their chart and I'll take the next 5 years to either get different rims that can handle the higher psi if that's what I decide to do, or chose a different tire that stays within the range of my rims it is only 200 bucks more to get sailun than the "good" Chinese tires (owned by cooper) I got.

I would have jumped right to the sailun but I had hand surgery yesterday and I had to have them on the 5th before I went for that. No one had sailun 637's in stock so I had to go with the Hercules power st2's this time.

Steve


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