Max tire rim pressure ?

DonMar · 07-23-2016, 12:47 PM

I upgraded the tires on my forest river surveyor today went to e load but could not find max rim pressure on rim. Went on line and it's 60 psi and the maxxis are good for 65 psi so I guess I will have too run them at 60 max. any thoughts on this ,I know that tires get a lot time here.

locogk · 07-23-2016, 12:53 PM

i keep mine at 65

clr · 07-23-2016, 01:16 PM

I would go to the tire pressure/ load rating chart for your tire and see how much your tire can carry at 60 PSI. If that meets your loading needs then I would stay with the 60 PSI and not over load the wheel with the 65 PSI pressure. If you cannot find a chart for your exact tire I would look at the Goodyear or Michelin charts and use your tire size to find the correct chart.

**Tireman9** · 07-23-2016, 01:27 PM

I believe that the wheels should be able to handle the max pressure marked on the sidewall of the tire that the RV company provided.

You can always ask FR "Customer Service" to confirm that "the wheels they provide can handle the max inflation on the tire they supply."

DAISY BOYKIN · 07-23-2016, 01:56 PM

Web site for aluminum rims tire pressure can be found here www.series06.com

Buckskin · 07-24-2016, 07:56 AM

I run my tire pressure slightly less than max pressure called out on sidewall of tire. This way when tire heats up it will be about max pressure. Too little pressure may cause tire failure.

**Tireman9** · 07-24-2016, 09:09 AM

Quote:

Originally Posted by Buckskin

I run my tire pressure slightly less than max pressure called out on sidewall of tire. This way when tire heats up it will be about max pressure. Too little pressure may cause tire failure.

As a tire engineer I can tell you that is not the best approach for TT owners.

TT tires should run CIP as the tire pressure on the sidewall associated with the max load. You do not need to worry about pressure build up if the tire is not overloaded and you do not exceed the max speed (65 for most ST type tires) This pressure increase of a few psi is normal and accounted for in tire design.

The lower you start the pressure the greater will be the pressure increase.

You also want to lower the Interply Shear in the TT tires. This is the force that is trying to tear the belts and tread off the body of the tire.
If you want to learn more about this force, that is high in TT due to trailer suspension design you can Google Interply Shear tires
and read the technical posts and papers or simply increase your cold pressure

SeaDog · 07-24-2016, 09:35 AM

Having 14" rims I can only move up to D rated tires however according to my reading my aluminum rims are good to 80psi much higher then the D tire max. always interesting to read the tech points by TM

Coolharts · 07-24-2016, 12:51 PM

Quote:

Originally Posted by Tireman9

As a tire engineer I can tell you that is not the best approach for TT owners.

TT tires should run CIP as the tire pressure on the sidewall associated with the max load. You do not need to worry about pressure build up if the tire is not overloaded and you do not exceed the max speed (65 for most ST type tires) This pressure increase of a few psi is normal and accounted for in tire design.

The lower you start the pressure the greater will be the pressure increase.

You also want to lower the Interply Shear in the TT tires. This is the force that is trying to tear the belts and tread off the body of the tire.
If you want to learn more about this force, that is high in TT due to trailer suspension design you can Google Interply Shear tires
and read the technical posts and papers or simply increase your cold pressure

Great info!!

In your opinion what is the best tire for a travel trailer, all of us are trying to prevent blowouts especially from our OEM China Bombs. Maxxis seems to be a choice of many, some say ST, some say LT, it is very confusing.

Airdale · 07-24-2016, 02:06 PM

Quote:

Originally Posted by Buckskin

I run my tire pressure slightly less than max pressure called out on sidewall of tire. This way when tire heats up it will be about max pressure. Too little pressure may cause tire failure.

The correct tire pressure for your OE tires is found on the tire placard, certification label and in the vehicle owner manual.

Search = Tires | Safercar -- National Highway Traffic Safety Administration (NHTSA)

Tom48 · 07-25-2016, 11:51 AM

Quote:

Originally Posted by DonMar

I upgraded the tires on my forest river surveyor today went to e load but could not find max rim pressure on rim. Went on line and it's 60 psi and the maxxis are good for 65 psi so I guess I will have too run them at 60 max. any thoughts on this ,I know that tires get a lot time here.

We ran 80 psi lr Es with lr C 60 psi rims when we upgraded the tires on the old trailer from C to E and went years with no issues. We didn't ever have another flat or even a pressure leaking issue for years after the change. I sure would not worry about 65 lbs on a 60 psi rated rim.

mnoland30 · 07-25-2016, 04:52 PM

On cars and trucks, there is a specified tire pressure based on (I assume) the weight and handling of the vehicle. Why is it different for a trailer tire? It seems if you upgrade the load rating on your trailer and up the pressure, it would ride rough and be hard on the trailer.

Airdale · 07-25-2016, 08:08 PM

Quote:

Originally Posted by mnoland30

On cars and trucks, there is a specified tire pressure based on (I assume) the weight and handling of the vehicle. Why is it different for a trailer tire? It seems if you upgrade the load rating on your trailer and up the pressure, it would ride rough and be hard on the trailer.

Tire inflation pressures are not arbitrary, they are set by vehicle manufacturers as described - in part - in this reference and others referenced within this one.

https://www.gpo.gov/fdsys/pkg/CFR-20...sec571-110.xml

whatsupchuck · 07-25-2016, 08:50 PM

All that information must mean something to the fed. O'Reily asks simple questions and never gets an answer. Same with that.

FR sent our trailer with spare rim rated for 2150 lbs. with D range tires rated for 2450 lbs. I believe and I'm looking at E range Maxxis.

"At this point in time, what difference does it make?"

Airdale · 07-26-2016, 10:11 AM

Quote:

Originally Posted by whatsupchuck

All that information must mean something to the fed. O'Reily asks simple questions and never gets an answer. Same with that.

FR sent our trailer with spare rim rated for 2150 lbs. with D range tires rated for 2450 lbs. I believe and I'm looking at E range Maxxis.

"At this point in time, what difference does it make?"

What it boils down to is your perception of safety. I'm surprised your would contemplate using tires with a maximum 80 PSI rating on rims with 65 psi rating.

Why did you not return the spare tire/rim assembly to FR?

Tire manufacturers must provide a list of acceptable rims to be used on every tire they make. They must provide access of such lists to the public. All tire retailers have such listings for the tires they carry/sell.

Vehicle manufacturers are required to make tire/rim fitments that are appropriate, meaning the OE fitments meet minimum standards for the vehicle they are fitted to.

When making selections for replacement tires other than those the size of the OE tires, an owner really needs to consult with tire retailers that are fully trained in the procedures that follow tire industry standards for such fitments.

If you are so dissatisfied with the OE tires that came on your unit why would you use your replacements on rims that are not earmarked for the tires you want to use?

SeaDog · 07-26-2016, 10:37 AM

I honestly believe there is some confusion here. I think folks are mixing max tire pressure with max rim pressure. I have never heard of a trailer rim limited to 65 psi, with that said I may be wrong as often happens. I promise not to get offended if someone tells me I'm full of well you know.

Airdale · 07-26-2016, 11:02 AM

Quote:

Originally Posted by SeaDog

I honestly believe there is some confusion here. I think folks are mixing max tire pressure with max rim pressure. I have never heard of a trailer rim limited to 65 psi, with that said I may be wrong as often happens. I promise not to get offended if someone tells me I'm full of well you know.

Reference from a popular rim OEM provider.

T02 | Sendel Wheels

SeaDog · 07-26-2016, 11:13 AM

holly molly batman enough said

**Tireman9** · 07-27-2016, 10:58 AM

Quote:

Originally Posted by mnoland30

On cars and trucks, there is a specified tire pressure based on (I assume) the weight and handling of the vehicle. Why is it different for a trailer tire? It seems if you upgrade the load rating on your trailer and up the pressure, it would ride rough and be hard on the trailer.

Trailers are run at or above the tire max load capacity almost all the rime while cars almost never are.
The Interply Shear comes from the fact that trailer tires are dragged around all corners while cars and TV are not. This increases the force trying to tear the tire apart by about 24%

**Tireman9** · 07-27-2016, 11:03 AM

Quote:

Originally Posted by whatsupchuck

All that information must mean something to the fed. O'Reily asks simple questions and never gets an answer. Same with that.

FR sent our trailer with spare rim rated for 2150 lbs. with D range tires rated for 2450 lbs. I believe and I'm looking at E range Maxxis.

"At this point in time, what difference does it make?"

Rim should be returned to FR for replacement. Also a complaint filed with NHTSA for FR providing potentially unsafe wheel for the application.

Good for you for making the effort to learn what the ratings are on the parts FR gave you.

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