Tire pressure

Your 17.5" Sailuns have a 6008 lb capacity per tire at 120 psi on a trailer with 7k or even 8k axles.
The 16" Sailun G load range with the 4080 lb or 4400 lb capacity would have been a better fitment.
But you gotta' work with what you got.
Remember some input comes from some that have just a few years pulling a couple of road trailers.

Lots of websites 'splains why we should use max sidewall pressures in a tire on a trailer. However this recommendation works best if the tire load capacity has been fitted to the trailers axle ratings with a 10-15 percent reserve capacity.

So we find some websites that says this when we over tire the trailer such as a 6000 lb tire on a 7k axle;

fifthwheelstreet.com

Step #5..
Selecting the Correct Tire Pressure for Your Trailer
We at Fifth Wheel St. no longer recommend adjusting trailer tire inflation pressure below the maximum load PSI rating molded on the sidewall (and only if the wheel/rim is appropriately rated) regardless of the measured scaled weight of individual tire or axle positions for all multi-axle trailers.

However, we do strongly recommend weighing individual trailer tire positions to ensure none of the axles or tire positions are overloaded. Reports have shown that trailers do not have equal weight across all tire positions. Some RV load configurations may reveal as much as 20% difference between the front and rear axle. This especially true for Toy Haulers. It is possible that mismanaged trailer load distribution will cause one end of an axle or a tire to be overloaded. It has been stated, but never confirmed by any RV Weighmaster, that there are many RVs traveling on the road with at least one tire or axle side overloaded. The only way to ensure tires and or axles are not overloaded is to weigh each tire position on your trailer. Unfortunately, attempting to obtain accurate individual tire position weight is practically impossible at all truck scales.**

azdryheat wrote:
What I know is I've had two 5th wheels in the last eight years running Michelin truck tires, traveling all over the US in the heat of summer and have yet to have a tire issue. I don't baby my tires and I don't run them at max pressure. My current Michelins are five years old and are wearing fine. So called tire experts can talk about shear and degrees and such but I'll talk from actual tire usage and the 100% reliability of my truck tires. Truck tires are tough and can take the abuse, Chinese trailer tires can't.

Looks like a well thought out post, good points until that last sentence. That mis-statement throws the whole post into doubt.

My Sailun ST tires, and almost every other one I've read about have lasted with no issues. Chinese-made and an ST tire, but an excellent tire that I would buy again in a heartbeat.

Planning wrote:

azdryheat wrote:
Why should my trailer be any different?

Because it is a different type of vehicle with different types of forces impacting the tires. With tires on multi-axle trailers, like RV trailers, the belt (interply) shear forces can be 24% higher than the belt shear forces of identical size, load and inflation tires on a motorized vehicle.

The internal structural forces are different for torque than for high "slip angle" which is the situation in trailer application. Front tires on cars, motorhome or tow vehicles experience slip angle usually in the 1° range while trailer tires are subject to angles in the 10° and greater range. The forces are NOT linear. 10° can generate significantly more shear than 1°.

Here is a large amount of data compiled by tire engineers regarding this issue: http://www.rvtiresafety.net/search/label/Interply%20Shear

What I know is I've had two 5th wheels in the last eight years running Michelin truck tires, traveling all over the US in the heat of summer and have yet to have a tire issue. I don't baby my tires and I don't run them at max pressure. My current Michelins are five years old and are wearing fine. So called tire experts can talk about shear and degrees and such but I'll talk from actual tire usage and the 100% reliability of my truck tires. Truck tires are tough and can take the abuse, Chinese trailer tires can't.

ChuckSteed wrote:
Sailun tires are as good as any GY tires made for RVs... personally I run a Geo Star Chinese made G rated 14 ply tire... starting 4th season... r7n them at 105 to 110 psi...

They will continue to perform quite well... GY G614 is a nice tire but not worth the cost factor when a good G rated 14 ply tire will work just as well

If you’ve got money to burn then buy the best....Sailun would be your huckleberry

I was using the GY G614 16 inch and changed into the Sailun S637 235/75R -17.5, for $178 per tire delivered.

The same GY tire/size would have cost me almost 3 times as much per tire, for the dubious process of obtaining a replacement tire in the event of a covered failure. Dubious since I had already experienced the process once, and it was definitely not "plug n play".

The Sailun tires are substantial in their construction; the sidewall strength is impressive, and the performance has been flawless. They are manufactured under ISO 9000 standards, and when I (soon) replace my TV tires I will be going with Sailuns there as well.

Sailun tires are as good as any GY tires made for RVs... personally I run a Geo Star Chinese made G rated 14 ply tire... starting 4th season... r7n them at 105 to 110 psi...

They will continue to perform quite well... GY G614 is a nice tire but not worth the cost factor when a good G rated 14 ply tire will work just as well

If you’ve got money to burn then buy the best....Sailun would be your huckleberry

azdryheat wrote:
Why should my trailer be any different?

Because it is a different type of vehicle with different types of forces impacting the tires. With tires on multi-axle trailers, like RV trailers, the belt (interply) shear forces can be 24% higher than the belt shear forces of identical size, load and inflation tires on a motorized vehicle.

The internal structural forces are different for torque than for high "slip angle" which is the situation in trailer application. Front tires on cars, motorhome or tow vehicles experience slip angle usually in the 1° range while trailer tires are subject to angles in the 10° and greater range. The forces are NOT linear. 10° can generate significantly more shear than 1°.

Here is a large amount of data compiled by tire engineers regarding this issue: http://www.rvtiresafety.net/search/label/Interply%20Shear

I run Michelin XPS Rib truck tires on my toy hauler. The tires are 5 years old and I've never run max psi in them, usually around 70 psi. The way I see it, my truck runs 70 front and 65 rear per the sticker, not the max pressure on the sidewall. My car runs 30 psi per the sticker, not the max pressure in the sidewall. I don't run max psi on my Harley. Why should my trailer be any different? Well built tires don't need to be babied for fear of exploding from heat, which is why I'll never buy trailer tires.

The trailer tire people say to run max air in the Chinese-made tires because they are total junk and will fail if they get much above room temperature. :)

I concur with those who say to air them all the way up. I wouldn't trust Chinese tires as far as I could throw them, but if I absolutely had to, I'd want to give them every imaginable chance to shed heat. I'm sure someone will be here to tell me how great these particular Chinese tires are, to which I am happy to tell them that it's a big market and to enjoy their purchase.

X2, rwake.

You need to know how much weight you have on your tires before you know what to inflate them to. They will not get hot quickly and cause a blowout if you don't have them inflated to 110 psi. I have a triple axle toyhauler with 12,000 lbs. on all three axles, with a max of 2500 lbs. on two tires. I run my G-rated Sailun tires at 90-95 psi., and have been doing so for nearly 5 years. My Sailuns show even wear and look to be good for several more years.

But you need to know how much weight you're carrying on your axles. Knowing how much weight you're carrying on individual tires is good, but sometimes that can be a hassle to get.

Personally I feel uncomfortable running my G-rated Sailuns under 90 psi, but I do know some who run pressures down in the 80's. But not me, in the summer I run 95 psi as a rule. 110 psi is too much pressure for my weight and beats me, and my trailer, to death on rough roads.