OEM rims rated for 110psi?

[Mikelff]

I have a 2018 Montana High Country 358BH. 41’, Anyone know if the OEM rims are rated for 110psi? Where on the rim would you find the psi rating stamp? I’m sure I’ll be crawling under there to look for it. Sure don’t want to pull the tire to look for it if I don’t have to. Thanks!

[2 Yoopers]

It’s stamped on the inside of the rim.

[beeje]

Just looked at a friends (new to him ) 2010 Montana. I could see the 3750lbs 110psi rating on the back side of the wheel spoke without removing it.

It has been reported in multiple places on this forum that all montanas from 2010 forward have 110psi rated wheels.

[Mikelff]

New to forum so thanks for the info.

[Mikelff]

Originally Posted by beeje

Just looked at a friends (new to him ) 2010 Montana. I could see the 3750lbs 110psi rating on the back side of the wheel spoke without removing it.

It has been reported in multiple places on this forum that all montanas from 2010 forward have 110psi rated wheels.

Just an FYI, the psi rating was on every spoke of the wheel. Just got back from crawling under the rig. Now have to find some new tires.

[beeje]

Originally Posted by Mikelff

Just an FYI, the psi rating was on every spoke of the wheel. Just got back from crawling under the rig. Now have to find some new tires.

I've never seen that on every spoke

[432bartman]

Learning something new everyday. I never knew the rims indicate a tire pressure. I just thought it was only on the tires. Thanks for the info.

[Mikelff]

Just spoke with my area factory Montana sales rep. The new High Country units now come with F rated tires. The Montana units are now coming with G rated tires. F rated tires are 12 ply, G rated are 14 ply. Being new to the forum, I had already replaced my China bombs with the Goodyear Endurance E rated tires that were the tire size and rating originally shipped on the unit. He also said to confirm the psi rating on the back of the rim. He will check to make sure my factory rims will take a G rated tires. As long as the rims will handle the G rated tire he saw no reason not to use them. So Montana did upgrade their tires to meet the new specs.

[Creeker]

The HC's have been coming from the factory with F rated tires since at least 2018. We looked at dozens before settling on our '19 model. All of them had F rated tires. If I recall correctly all were Rainier brand. I know all '19s were Rainier ST 235/80/16's. Rated for 3860lbs at 95psi. 81 MPH speed rating.

[Mikelff]

Originally Posted by Creeker

The HC's have been coming from the factory with F rated tires since at least 2018. We looked at dozens before settling on our '19 model. All of them had F rated tires. If I recall correctly all were Rainier brand. I know all '19s were Rainier ST 235/80/16's. Rated for 3860lbs at 95psi. 81 MPH speed rating.

Must have changed sometime mid year after my 2018 model was made if they made the switch in 2018. My label says ST 235/80/16E. Just my luck. Good info.

[sourdough]

IMO opinion those E rated tires should come off. They appear to have come on the trailer prior to the new RVIA recommendation of a 10% cushion (LRF). The Es will get you in trouble and was a primary driver IMO of why so many OEM tires failed continually - they were overloaded due to underrated tires from the factory. My HC came with LRF Raniers. They were replaced with Sailun S637 tires before it left the lot. I would highly recommend you do the same or at least get LRF tires. My wheels were rated for 110 psi. Look on the back of the rim, sometimes on a spoke. I've had the stamped with psi and/or load ratings.

[CalandLinda]

Originally Posted by sourdough

IMO opinion those E rated tires should come off. They appear to have come on the trailer prior to the new RVIA recommendation of a 10% cushion (LRF). The Es will get you in trouble and was a primary driver IMO of why so many OEM tires failed continually - they were overloaded due to underrated tires from the factory. My HC came with LRF Raniers. They were replaced with Sailun S637 tires before it left the lot. I would highly recommend you do the same or at least get LRF tires. My wheels were rated for 110 psi. Look on the back of the rim, sometimes on a spoke. I've had the stamped with psi and/or load ratings.

I've researched the OPs trailer's specs and I'm convinced the vehicle's certified axles are 6400#. A picture of the vehicle certification label would confirm that.

With the axles set a 6400# the OEM ST235/80R16 LRE tires would qualify for the 10% reserve load capacity.

For many years Keystone has played the number's game with the ST235/80R16 LRE tires. Those tires are manufactured with 3 distinct load capacities, 3420#, 3500# & 3520# all @ 80 PSI.

Because (officially) the minimum vehicle tire standard is set with the information provided on the vehicle certification label, the OPs tires were probably 3520#. That would make the Endurance ST trailer tires unsuitable for replacing the OEM tires because their load capacity is 3420#.

It's a common error for consumers to read a trailer's brochure which will tout 7000# axles and load the trailer accordingly. Theoretically the vehicle would then be 1200# overweight and the OEM tires would be at great risk of failure.

That's the primary reason I always refer to trailer axles as being vehicle certified. The GAWRs listed on the vehicle certification label depict the maximum load capacity for that vehicles axles.

[Mikelff]

Originally Posted by CalandLinda

I've researched the OPs trailer's specs and I'm convinced the vehicle's certified axles are 6400#. A picture of the vehicle certification label would confirm that.

With the axles set a 6400# the OEM ST235/80R16 LRE tires would qualify for the 10% reserve load capacity.

For many years Keystone has played the number's game with the ST235/80R16 LRE tires. Those tires are manufactured with 3 distinct load capacities, 3420#, 3500# & 3520# all @ 80 PSI.

Because (officially) the minimum vehicle tire standard is set with the information provided on the vehicle certification label, the OPs tires were probably 3520#. That would make the Endurance ST trailer tires unsuitable for replacing the OEM tires because their load capacity is 3420#.

It's a common error for consumers to read a trailer's brochure which will tout 7000# axles and load the trailer accordingly. Theoretically the vehicle would then be 1200# overweight and the OEM tires would be at great risk of failure.

That's the primary reason I always refer to trailer axles as being vehicle certified. The GAWRs listed on the vehicle certification label depict the maximum load capacity for that vehicles axles.

The label on the rig says the axles are rated at 3173 KG, 7000 pounds. Tires coming off and replaced.

[eZAK]

So here is some more fuel for for the fire:

According to American Wheels, Tire Guys, and several forums;

The 'Max PSI' found on the back side of most all rims is there for the installer only and it indicates the maximum air pressure required to seat the bead on the tire!

Further more, two different rim mfg.. have stated that they know of no rim failure do to over inflation pressure. Tire failure Yes, rim failure No

[CalandLinda]

Originally Posted by eZAK

So here is some more fuel for for the fire:

According to American Wheels, Tire Guys, and several forums;

The 'Max PSI' found on the back side of most all rims is there for the installer only and it indicates the maximum air pressure required to seat the bead on the tire!

Further more, two different rim mfg.. have stated that they know of no rim failure do to over inflation pressure. Tire failure Yes, rim failure No

The maximum PSI inflation pressure allowed for installers when seating tire beads is 40 PSI.

Never exceed the maximum pressure and/or load capacity of the rim/wheel.

The above statements are established tire industry standards.

Current FMVSS standards do not require wheels to have load and PSI values displayed on them. However, most OEM providers request those values be molded on the wheel to help them insure they are using the correct wheel specifications for OE fitments.

Wheel manufacturers are required to provide wheel specifications on request. They are also required to insure wheels they build have the manufacturers name and model number on each individual wheel they manufacturer.

Some wheel manufacturers will only provide wheel load capacities. When that happens the installer cannot inflate the wheel to a PSI value higher than what is necessary to meet the maximum load capacity of the wheel. Manufacturers that provide both load capacity and recommended inflation pressures on their wheels are saying the maximums should never be exceeded.

If in doubt you will find most of the information above in the USTMA or FMVSS standards. They are easily found by searching the WWW.

[eZAK]

Yes, I did My research and talked to experts in the field!
Which is why I posted what I did.

"The maximum PSI inflation pressure allowed for installers when seating tire beads is 40 PSI."

Not entirely true! The manufacture of the RIM will often state the maximum pressure that the rim can handle to seat the bead!
Tire manufactures on the other hand will often have a much lower maximum PSI,
Usually between 30 and 45 psi.

As far as the Law goes (example from Cali S3325) "(e) Unless otherwise recommended by the manufacturer, tires shall not be inflated beyond a maximum of 40 psi to seat the beads. During inflation, tire beads shall be inspected for proper seating at intervals not to exceed 20 psi. Tires not properly seated at 40 psi, or at the maximum psi recommended by the manufacturer, shall be completely deflated before making the adjustment of the tire, rim or wheel components. Except as permitted in Section 3326, tires shall be in a restraint device when seating the beads."

"Never exceed the maximum pressure and/or load capacity of the rim/wheel."

While this is True, The Maximum PSI for any particular Rim can not be determined until it is stated by the manufacturer of that rim.

So, The point being [baring any defects] , in all likelihood the tire will give out to ovcer inflation well before a rim does!

[sourdough]

So, I guess this debate is "enlightening"? When I, or the tire shop, puts a tire on the rim and pull/plop/twist it to get it to take air to "seat", do I or them put a pressure gauge in it and say "oops, it's 40 psi and it didn't seat"? Of course not. Put it on there, get the tire to take air and wait for it to "pop". Seems to me the "seating" pressure is kind of irrelevant - the tire HAS to seat to air it up and use it. Never saw a tire explode while being seated on a rim. JMO

[CalandLinda]

NEVER INFLATE BEYOND 40 PSI TO SEAT BEADS.
NEVER STAND, LEAN, OR REACH OVER THE ASSEMBLY DURING INFLATION.


USTMA .... https://www.ustires.org/sites/defaul...TruckTires.pdf .... Page #27.

Read everything. It tells what to do if 40 PSI didn't seat the bead.

[mhs4771]

Have you ever watched a Truck Service Center inflate Truck tires?? The new tire and rim assembly are put into a cage before applying pressure, because the amount of pressure is so great if were to come apart it could kill the tech.
I would bet money it took more than 40 PSI to seat my 125 PSI "H" tires on the rim.
Those numbers and specs sure sound like it pertains to Passenger Tires not heavy Trailer tires.

[CalandLinda]

Originally Posted by mhs4771

Have you ever watched a Truck Service Center inflate Truck tires?? The new tire and rim assembly are put into a cage before applying pressure, because the amount of pressure is so great if were to come apart it could kill the tech.
I would bet money it took more than 40 PSI to seat my 125 PSI "H" tires on the rim.
Those numbers and specs sure sound like it pertains to Passenger Tires not heavy Trailer tires.

Maybe you should read page #27 in the reference in my last post.

I try real hard to post the way its supposed to be done; not how some tire shop does it.