Trailer Wheel PSI Ratings

[bsmith0404]

During different discussions on this forum, it has been stated that the max psi rating on trailer wheels is a cold pressure rating with tolerance for higher pressures when the tires heat up. According to reps at Sendel Wheel, that IS NOT accurate. The max psi listed for the wheel is just that MAX. I have the Sendel T03 rated for 100 psi on my RV. I installed Carlisle 235/85/16F tires with a cold pressure of 95 psi. When they heat up, the pressure typically rises to 104-105 range. Sendel recommended removing the tires or wheels ASAP., not doing that since it's just sitting in storage with about 90 psi in them. I'm contacting Carlisle to see if they can recommend a lower psi for the tire since I have a lot of room on the weight rating vs actual weight. If I can drop the tries to 85 or 90 psi cold I should be good. I really don't want to tell the DW that I need to get new wheels for the camper, that wouldn't go over well since she didn't understand why I was replacing tires after only owning it for a year.

[PARAPTOR]

I called Carlisle before I purchased the ST235/85R16 F rated 3960 lb at 95 PSI and questioned the tire PSI I should use since I had 7K axles. Their response was they wanted 95 PSI in those tires regardless of total weight carried. Personally I thought at 95 PSI the Raptor had more of a bounce than the original china bombs ST235/80 R16 E rated at 80PSI. I think getting to 105+ PSI on the road is not unreasonable

EDIT: BRENT just curious what is max weight/PSI stamped on the inside of the rim? Be interested in what they tell you

[bsmith0404]

max on the inside of the rim is 100. On my last trip I started out with 95 and hit 105 max, but most of the time they were 98-101. I was actually surprised they didn't get higher, but the temps didn't increase much either, only about 15-20 degrees.

[GaryWT]

I believe my tires same max cold on the sides so in the morning I check them and we are good. Not sure is how close to max psi increase weight carrying at all.

On the other hand, tires not inflated to what they should be will heat up more and thus can cause the tread to peel off the tire base thus causing a blowout.

[PARAPTOR]

If I recall there was a group of members who went with the G rated tires normal 110 PSI. think they were Sailun S637 wonder what rims they used? stock or upgraded?

[bsmith0404]

That got me thinking because many threads have discussed people going to a G rated tire and they said their wheels were rated for 110. I checked Sendel's website and couldn't find any wheels rated higher than 110. Based on the information they gave me we wouldn't be able to use a G rated tire with any of their wheels. I sent another message asking them for recommendations. I will update this thread with their response when I get it.

[bobbecky]

All the ratings on these wheels are for the cold inflation pressure. The design of all wheels allow for pressure increases due to heat buildup while traveling. If your wheels are rated 100 psi cold, then the 95 psi for those tires is just fine. Even if they increase to say 120 psi when in use, that is not the cold pressure, so nothing to worry about.

[flybouy]

Sounds to me like both tire and wheel manufactures gave you the safe "CYA" leagalese advice.

[JRTJH]

Originally Posted by bobbecky

All the ratings on these wheels are for the cold inflation pressure. The design of all wheels allow for pressure increases due to heat buildup while traveling. If your wheels are rated 100 psi cold, then the 95 psi for those tires is just fine. Even if they increase to say 120 psi when in use, that is not the cold pressure, so nothing to worry about.

bobbecky,

The statement you've made (highlighted in red) is the purpose for this thread. The following quote from the OP's first post indicates that the representative he spoke with at Sendel Wheel Company stated the opposite,
("During different discussions on this forum, it has been stated that the max psi rating on trailer wheels is a cold pressure rating with tolerance for higher pressures when the tires heat up. According to reps at Sendel Wheel, that IS NOT accurate. The max psi listed for the wheel is just that MAX.")

The factory making the wheels gives information that there is NO allowance for pressure increases. One of these statements is incorrect, either yours or the one from Sendel. Hopefully we can obtain the "final answer" to this question and resolve the "which one is right" situation.

[tank45]

I put Sailuns on my stock (110 psi) wheels. I have been running them at 110 psi because I also thought there would be allowance made for heat/pressure build up when traveling. Perhaps I should drop my pressure a bit?

[Quad]

Mine is stamped max pressure of 100 psi also on my sendel wheels. However when speaking to a rep from sendel he would not give me a written response over email stating anything other then what you've been told bsmith. But he asked me to call him. I did and after explaining to him what and why I was doing. He told me my wheels can handle higher pressure with metal bolt in valve stems. However he nor sendel will give that blessing as their wheels have been rated at 100 psi max and repeated his story book manufacture safety warnings and comments to me. His statement to me was a read between the lines kinda thing. Now that obviously doesn't make it right, or should everyone do it, or anyone for that matter. It's a "your doing this at your own risk" scenario. However I run my sendel wheels at 100psi cold and have the same support as my factory tires with a peace of mind in my opinion and enjoy my Sailuns a lot.


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[CWtheMan]

I'm not going to print an answer here even though it's obvious, because I don't have a written reference to refer to.

The SAE certifies all DOT certified rims. So a clear and concise letter or email addressed to them should generate a like answer.

On edit: Here is a useful reference; https://www.sema.org/federal-regulat...1#Tires-Wheels



CW

[GaryWT]

As I read this agIn, are you taking rims? When I first read wheels that is the complete set and I read the sidewall as to tire pressure. Would never dream that the rim had a limit on pressure, first I have heard of this but in my book it is poor planning for a company to make a rim that would not support a tire. Of course if I am still reading this wrong on will blame it on my brain being fried.

[gearhead]

Originally Posted by GaryWT

As I read this agIn, are you taking rims? When I first read wheels that is the complete set and I read the sidewall as to tire pressure. Would never dream that the rim had a limit on pressure, first I have heard of this but in my book it is poor planning for a company to make a rim that would not support a tire. Of course if I am still reading this wrong on will blame it on my brain being fried.

Huh?
Could you say that a different way, 'cause I'm lost now.

[bsmith0404]

Okay, just for clarification, I use rim and wheel as the same, i.e. steel wheel/rim. I've never heard of it as a wheel is the complete assembly.

I spoke to a rep today and basically the answer I got was that the wheels (rims) are tested for the SAE certification. Part of the testing in order for them to get the certification is that they are tested to roughly 10% over rated psi. That does not mean they are safe to run psi of 10% over, they just need to meet that in order to get that particular rating. He actually pulled some data and the 110 psi wheels he looked at were tested at 130 and 100 psi wheels were tested at 110. Sorry, I didn't get the numbers for 80 psi wheels.

He also seemed to be more concerned about weight ratings than psi ratings. He described the wheel like an aluminum can being crinkled back and forth in your hand, eventually it rips or gets a hole. Wheels do the same thing and after enough time they break. Typical failures are where the spoke meets the hub. Some of our members have experienced this, he said straight up it is a load issue.

He also stated that the T03 is one of the most copied wheels on the market because there was not a copy right on it. When I told him what the weight of my trailer was, he said he recommends getting a heavier wheel on it. The T03 will support it initially, but he feels it is not the right wheel and is too close to being overloaded. In time, he'd expect a similar type failure with the spoke near the hub. He recommended the TR8 an T11 for my Alpine.

Finally, he said tires and wheels are not speced out for the trailer they are being installed on. The trailer manufacturer just tells the tire/wheel company what size/weight rating they want and what price range. The tire/wheel manufacturers are not aware what they are being installed on. I took this statement as basically saying it wasn't my recommendation to put those wheels on your RV.

Hope this helps, please let me know if you have any questions

[CWtheMan]

This goes a long way back, and, of course, it’s from an old timer.

When I started working on wheels and tires in my Navy Aviation Rating they were off Beach Craft and Super Connies (which had expander tube brakes). Almost all wheels were in two pieces and held together with bolts. When the newer wheel assemblies started to become commonplace they were cast or molded into a single unit. For simplicity the two part wheels were called wheels and the single cast unit was called a rim.

Its kind of like the plies in a tire. They used to be all cotton and the tire strength was determined by the air pressure and number of plies. Then along came polyester, nylon, steel and other combos so the rating system was born. Back in the early days we referred to any tire with an 8 ply rating as really having 4 plies. That doesn’t work anymore because of other factors. About that time acronyms were becoming popular and we had a large appendix in our maintenance manuals to refer to when an acronym stumped us.

We just have to move on in life. Today we have our computers that tell us almost everything. I’m pretty good at finding things there too.

CW

[Javi]

Originally Posted by GaryWT

As I read this agIn, are you taking rims? When I first read wheels that is the complete set and I read the sidewall as to tire pressure. Would never dream that the rim had a limit on pressure, first I have heard of this but in my book it is poor planning for a company to make a rim that would not support a tire. Of course if I am still reading this wrong on will blame it on my brain being fried.

Originally Posted by gearhead

Huh?
Could you say that a different way, 'cause I'm lost now.

I'll translate it to Texan for y'all...

He's a thinkin' wheels is rims with tires on them and reads the pressure limit on the tire as the gospel of the bunch..

And he'd never figure in a months worth of Sundays that a rim wouldn't take any tire that would fit around it... never mind how much pressure..

Oh... somehow he fried up a mess of brains but can't find nobody to blame it on..

[gearhead]

Originally Posted by Javi

I'll translate it to Texan for y'all...

He's a thinkin' wheels is rims with tires on them and reads the pressure limit on the tire as the gospel of the bunch..

And he'd never figure in a months worth of Sundays that a rim wouldn't take any tire that would fit around it... never mind how much pressure..

Oh... somehow he fried up a mess of brains but can't find nobody to blame it on..

Oh! OK. Now that you translated it, I completely understand. lol
Sending some rain up your way. Holler when you had enough.

[gearhead]

Back to being serious....looking at the Sendel website for my TO3BM 16" with 6 lugs and 80PSI with 3580# capacity, the 8 lug at 100PSI is also rated at 3580. I assume it is the same wheel with just the different lug pattern.
I'm running 5200# Dexter axles and at the most both axles are 9000# combined per several CAT scale visits. I'm well under the capacity of the axles and the wheels. My Maxxis E tires are rated at 3420. I think I'm good everywhere.
But...I'm thinking 2-3 years down the road I may want to step up to F rated Carlisle at 3960# at 95 PSI. I'm thinking (wishfully) that I'm 5PSI to the good with my current wheels.
http://www.sendelwheel.com/wheels/t03bm
Opinions?

[Barbell]

I also run my Sailuns at 110 psi and I think they would not have stamped the "110 psi" on the wheel unless they expected that you would never move the trailer.