Tire Wear Question

[thd]

I have a Seismic 355W and I picked it up from storage today. I was underneath just checking stuff and notice cupping on the edge of my tires. Both sides. Left front is the worst, with significant cupping inside and out. Tires are G rated and inflated to 110psi, always run max pressure.

What causes cupping on both inside and outside edges of the tire? Alignment issue?

I also started using a TPMS and was wondering what the max pressure alarm should be?
I set the alarm for 130 psi, and when the outside temp was above 90 degrees, the tires would exceed 130 psi. Is this normal?

[thd]

Ok, here is the response I received from Sailun.

"It is normal for the pressure to increase by 15% to 20% in normal operating conditions. The tires are engineered with this fact in mind."

And this one caught me by surprise, as I have always thought differently.

"In your case, the cupping is likely a result of over inflation. Over inflation causes a “rounded” or “crowned” footprint on the road where the shoulders are not touching. This creates a constant squirm causing the cupping you describe.

Most trailer manufacturers design their trailers to take 80 psi in the tires to carry the load. What you need to do is to weigh your trailer fully loaded then divide by the number of tires to find the per tire weight. You can then use the attached load and inflation chart to find your tire size, weight per tire and recommended air pressure. I am going to guess it will be around 80 psi. You can build 5-10 psi safety into the pressure you use. It is safe to run less than 110 psi in the Sailun tires. They were engineered to meet the load and inflation shown on the chart."

According to the chart I was sent, I should be at 80lbs for the weight on my axles. I have always run my tires at max pressure, but I upgraded to G rated because the E rated were running close to max load and for piece of mind. I guess for I will try a lower pressure and see if that makes a difference.
And I check my tires and feel the hubs for excessive heat whenever I stop while traveling. It's one of the reasons I started using TPMS, I want to catch a problem before it becomes a bigger issue if possible.

BTW...Sailun was very responsive to my inquiry, which I found admirable.

[CapriRacer]

thd wrote:
How about how much increase in pressure one can expect that is considered normal? Is 130+ for a 110psi g rated tire normal in warmer conditions?
Be nice to know where to set the high pressure alarm on the TPMS.

That seems high.

The rule of thumb that I have used for Passenger car and Light Truck tires is a maximum of 10%, with 15% being a call for immediate action. You're at 18%+

First, I think it is a good idea to check the tires on the trailer before every tow. Pressure and condition (by rubbing your GLOVED hand around the circumference, looking for bulges) If you aren't doing that, I suggest you add it to your checklist.

[thd]

BTW...I have Sailun S637's. I emailed Sailun to get there opinion on the tire wear issue and max pressure when driving. Will post any feedback I get.

[thd]

Thanks for the replies.
The wheel, which is aluminum, was just replaced under warranty, so may be out of round. I will check into that.
I just got back from a 1300 mile round trip to Nevada. Tires got to 131psi. Pressures were within 2psi to 3psi all around, and tire temps were were all very even. Elevation may play into this? I am close to sea level and traveled through areas as high as 6,000ft. Most of the drive was at elevations of 4,000ft or higher.

[allcool]

Dirtclods wrote:
Tire wear: https://www.michelinb2b.com/wps/b2bcontent/PDF/Usual_Suspects_Steer_BFG_EN.pdf

While that chart you linked too is for 'steer tires', it is somewhat applicable to all,,, somewhat.

thd wrote:
I have a Seismic 355W and I picked it up from storage today. I was underneath just checking stuff and notice cupping on the edge of my tires. Both sides. Left front is the worst, with significant cupping inside and out. Tires are G rated and inflated to 110psi, always run max pressure.

What causes cupping on both inside and outside edges of the tire? Alignment issue?

I also started using a TPMS and was wondering what the max pressure alarm should be?
I set the alarm for 130 psi, and when the outside temp was above 90 degrees, the tires would exceed 130 psi. Is this normal?

imo, the wear you're talking about "cupping inside and out" is caused by tire/wheel/hub out of balance, out of round. Probably a lot out of balance. A very loose wheel bearing will also cause this type tire wear.

An hot to cold increase from 110psi to "the tires would exceed 130 psi" seems excessive to me.
iirr, 5-10psi increase from hot to cool is normal for my 80psi e rated tires in normal driving conditions.

If your tire is getting a constant bounce or scrub while driving, that may heat it up enough to make a 20+psi increase..?
If you fill tires with an inert gas instead of air, you will in theory get less increase.

jmo

[Dirtclods]

Tire wear: https://www.michelinb2b.com/wps/b2bcontent/PDF/Usual_Suspects_Steer_BFG_EN.pdf

[time2roll]

Check for out of round also.

Steel wheel? Have it balanced with a lug centric adapter on the machine. Hole in a steel wheel is just stamped and not always centered perfect. The standard cone adapter will have the wheel off center. Some worse than others.

Also you could have someone follow you to observe the tire if it is really bouncing badly.

[thd]

time2roll wrote:
Cupping is usually out of balance, bad shocks, worn components. Created by the tire oscillating up and down as you travel at speed.

No shocks, and I fairly recently upgraded the suspension parts with a wet bolt kit and heavy shackles.
The wheel that has the tire that is wearing the most was recently replaced under warranty. I had the new one balanced when I had it mounted. Maybe I should have them recheck it.

[time2roll]

Cupping is usually out of balance, bad shocks, worn components. Created by the tire oscillating up and down as you travel at speed.

[thd]

How about how much increase in pressure one can expect that is considered normal? Is 130+ for a 110psi g rated tire normal in warmer conditions?
Be nice to know where to set the high pressure alarm on the TPMS.

[CapriRacer]

thd wrote:
..... I have about 1/16th of an inch gap on the front edge of the front tire on both sides. Looks like a very slight toe in and even on both sides. The link said less than 1/8th of an inch is ok.
.......

My experience with cars is that 1/32nd each side (1/16 total) is where this has to be to avoid tire wear problems. I don't know if that applies to trailers, but I would think it would.

[thd]

azdryheat wrote:
Tight turning plays heck with tires.

Now that may be a possibility. I live on a cul-de-sac and its a tight turn around to leave. Usually the tightest turn I do on pavement. Just didn't think a quick turn around like that would wear that much?

[azdryheat]

Tight turning plays heck with tires.

[thd]

Thanks for the link. Good info.
I was able to check it fairly easily. I have about 1/16th of an inch gap on the front edge of the front tire on both sides. Looks like a very slight tow in and even on both sides. The link said less than 1/8th of an inch is ok.
Also, with the tpms, I am not seeing excessive heat in any one tire. The only difference in temperature I see is when the sun is shining on one side. The side facing the sun always runs a few degrees warmer.