PDA

View Full Version : OEM rims rated for 110psi?


Mikelff
08-09-2020, 11:09 PM
I have a 2018 Montana High Country 358BH. 41í, Anyone know if the OEM rims are rated for 110psi? Where on the rim would you find the psi rating stamp? Iím sure Iíll be crawling under there to look for it. Sure donít want to pull the tire to look for it if I donít have to. Thanks!

2 Yoopers
08-10-2020, 04:59 AM
Itís stamped on the inside of the rim.

beeje
08-10-2020, 05:24 AM
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
08-10-2020, 10:55 AM
New to forum so thanks for the info.

432bartman
08-10-2020, 10:59 AM
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
08-10-2020, 02:22 PM
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
08-10-2020, 05:39 PM
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
08-10-2020, 06:04 PM
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
08-10-2020, 06:09 PM
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
08-11-2020, 09:01 AM
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
08-11-2020, 10:52 AM
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.

beeje
08-11-2020, 10:56 AM
Make sure you take the time to handle each different tire so you can compare what comes off the what's going on. The difference should be substantial

Mikelff
08-11-2020, 11:23 AM
Make sure you take the time to handle each different tire so you can compare what comes off the what's going on. The difference should be substantial

Not sure I understand what you mean. You talking about weights of the tires?

beeje
08-11-2020, 11:25 AM
The way I read it you were replacing the tires on the camper

Mikelff
08-11-2020, 11:26 AM
The way I read it you were replacing the tires on the camper

Yes, that is the plan.

beeje
08-11-2020, 11:51 AM
That's what I thought. So yes I meant make sure you pick up an old tire and compare it to whatever you're putting on. If you're putting on G,s the different should be substantial

Mikelff
08-11-2020, 03:07 PM
That's what I thought. So yes I meant make sure you pick up an old tire and compare it to whatever you're putting on. If you're putting on G,s the different should be substantial

Lucky me. Discount tire will give me full credit for the two new tires I bought last Thursday, and pro rate the third tire I had to buy two weeks ago. The 4th tire might be a spare, have to see what they say. 😎

Mikelff
08-11-2020, 03:10 PM
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.

Mikelff
08-11-2020, 03:15 PM
FYI, was just under the rig and there a tags on the axles that also say they are rated at 7000 lbs. Thanks for doing the math, but new tires going on so really don’t have to worry about it. Stay safe!

beeje
08-11-2020, 04:01 PM
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

beeje
08-11-2020, 04:03 PM
Will do. What does the label on the camper State as far as axle capacity. Mine are 7000 pound axles also but the label States 6750. They were apparently de-rated because of the original tires that came on it

CalandLinda
08-11-2020, 07:03 PM
FYI, was just under the rig and there a tags on the axles that also say they are rated at 7000 lbs. Thanks for doing the math, but new tires going on so really donít have to worry about it. Stay safe!

Those tags are the axel manufacturer's certification tags. Their maximum load capacity for your vehicle is not valid, unless the vehicle certification label list's your GAWRs as 7000#. The vehicle certificating label is found on the trailer's left forward external section of the trailer.

All Trailer builders have the authority to set axle GAWRs to a load that is acceptable for a balanced load at certification time.

Mikelff
08-11-2020, 08:21 PM
Those tags are the axel manufacturer's certification tags. Their maximum load capacity for your vehicle is not valid, unless the vehicle certification label list's your GAWRs as 7000#. The vehicle certificating label is found on the trailer's left forward external section of the trailer.

All Trailer builders have the authority to set axle GAWRs to a load that is acceptable for a balanced load at certification time.

The label on my rig states axle rating is 7000 lbs. everything on the rig pertaining to the axles say they are rated at 7000 lbs.

CalandLinda
08-12-2020, 02:37 AM
The label on my rig states axle rating is 7000 lbs. everything on the rig pertaining to the axles say they are rated at 7000 lbs.

Than you should ask Keystone why they didn't comply with the RVIA 10% load capacity recommendation.

It would be worth a try because RVIA could pressure them to provide you with tires meeting their recommendations.

PSFORD99
08-12-2020, 08:23 AM
Than you should ask Keystone why they didn't comply with the RVIA 10% load capacity recommendation.

It would be worth a try because RVIA could pressure them to provide you with tires meeting their recommendations.


Plus the fact still remains he put on an E rated tire, which IMO is not adequate for his size of fifth wheel. He has already had issues with the E rated tire. He has the wheels for G rated 110 psi , and thats what needs to be on that fifth wheel. At the very least the Sailun S637 ST 235/80/16 rated for 4080 lbs @ 110 psi.

Some will promote the Goodyear G614 , also a G rated tire , IMO still not the weight rating @ 3750 lbs @ 110 psi. We have read issues ,and blowouts with these Goodyears for years ,probably one of the bigger reasons in years past was they just were not a good manufactured tire , now today with these heavier fifth wheels they do not have the needed weight rating. If you look at the Goodyear trailer tires , including the Endurance they just don't have a tire for these heavier Montana fifth wheels.

I believe at one time Keystone offered the G614 as an upgrade, and I believe now that is no longer true, they are not up to the weight rating needed . At the least the tires on the Montana fifth wheels are G rated ,and at least have the 4080 rating. The High Country it sounds like they should also be the same for the heavier ones.

Mikelff
08-12-2020, 08:58 AM
Than you should ask Keystone why they didn't comply with the RVIA 10% load capacity recommendation.

It would be worth a try because RVIA could pressure them to provide you with tires meeting their recommendations.

That will never happen. I bought this used. Itís out of warranty. And RVIA wouldnít do anything. Waste of time. New tires here Friday. Problem solved.

PSFORD99
08-12-2020, 09:02 AM
That will never happen. I bought this used. Itís out of warranty. And RVIA wouldnít do anything. Waste of time. New tires here Friday. Problem solved.


I thought you already got new tires, the Endurance .:confused:

Carl n Susan
08-12-2020, 10:01 AM
I thought you already got new tires, the Endurance .:confused:
The answer is in post #17

CalandLinda
08-12-2020, 10:07 AM
That will never happen. I bought this used. Itís out of warranty. And RVIA wouldnít do anything. Waste of time. New tires here Friday. Problem solved.

Just a note: The GY Endurance ST235/80R16 LRE does not qualify for service on 7000# axles.

PSFORD99
08-12-2020, 10:58 AM
Just a note: The GY Endurance ST235/80R16 LRE does not qualify for service on 7000# axles.


You would think they do as many people that are buying them. Great application for lighter boat trailers , ATV trailers etc. Plus they have a very shallow tread pattern .

PSFORD99
08-12-2020, 11:00 AM
The answer is in post #17

Thanks, wondering what tire he went to this time ,didn't see that ?

Mikelff
08-12-2020, 11:18 AM
I thought you already got new tires, the Endurance .:confused:

I did last Thursday. Also just joined the forum last Thursday. That is what all the brouhaha is about. Discount tire will take them back. My Sailuns will be delivered Friday. Will go on the rig Monday. Problem solved.

PSFORD99
08-12-2020, 11:23 AM
I did last Thursday. Also just joined the forum last Thursday. That is what all the brouhaha is about. Discount tire will take them back. My Sailuns will be delivered Friday. Will go on the rig Monday. Problem solved.

Thanks .Good choice ,great tire , I only wished we had a comparable tire made in the US. You won't be disappointed in the quality. I have had two sets of them .

You came to the right place for advice on these tires , I know you got beat up a little, but we mean well . Good luck on the Rv'ing

Mikelff
08-12-2020, 11:34 AM
Thanks .Good choice ,great tire , I only wished we had a comparable tire made in the US. You won't be disappointed in the quality. I have had two sets of them .

You came to the right place for advice on these tires , I know you got beat up a little, but we mean well . Good luck on the Rv'ing

Yup, sure beat a dead horse around here. Maybe we can let this lay for awhile.

PSFORD99
08-12-2020, 11:51 AM
Yup, sure beat a dead horse around here. Maybe we can let this lay for awhile.


For sure , its done. But for sure there will be another tire thread or truck, or hitch or whatever.

sourdough
08-12-2020, 11:51 AM
Yup, sure beat a dead horse around here. Maybe we can let this lay for awhile.



Mikelff, I know your are new to the site, and I'm sort of new, but not to RVs or RV websites. "Beating a dead horse" happens a LOT on RV forum topics. It's sort of the nature of the beast - no ill intent is meant. Sometimes the OP posts a resolution somewhere in the middle of a string of posts and it's missed so some posts might seem repetitive. Don't let it misle you. There is a ton of information here from knowledgeable folks; I know some of them from other forums and they can be very helpful in a time of need. Congrats on the new Sailuns and let us know how it goes, I'm very happy with mine (except they got dirty in FL and I haven't cleaned them yet). :D

eZAK
08-21-2020, 09:20 AM
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
08-21-2020, 02:36 PM
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
08-23-2020, 09:11 PM
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
08-23-2020, 10:00 PM
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
08-24-2020, 12:57 AM
NEVER INFLATE BEYOND 40 PSI TO SEAT BEADS.
NEVER STAND, LEAN, OR REACH OVER THE ASSEMBLY DURING INFLATION.


USTMA .... https://www.ustires.org/sites/default/files/CareAndService_PassengerAndLightTruckTires.pdf .... Page #27.

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

mhs4771
08-24-2020, 07:50 AM
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
08-24-2020, 08:37 AM
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.

beeje
08-24-2020, 08:58 AM
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.

I don't see what difference it makes anyway unless you were the one mounting the tires.

Back in my early years as a teenager I started out Mounting car and truck tires. Just Lube them up real good 99% of the time they seated fine. And yes I also change split rims and put them in a cage to seat and blow them up. And I have seen a few of the Rings fly off with lots of force.

CalandLinda
08-24-2020, 01:48 PM
I don't see what difference it makes anyway unless you were the one mounting the tires.

Back in my early years as a teenager I started out Mounting car and truck tires. Just Lube them up real good 99% of the time they seated fine. And yes I also change split rims and put them in a cage to seat and blow them up. And I have seen a few of the Rings fly off with lots of force.

Safety First.

PSFORD99
08-27-2020, 08:42 AM
I don't see what difference it makes anyway unless you were the one mounting the tires.

Back in my early years as a teenager I started out Mounting car and truck tires. Just Lube them up real good 99% of the time they seated fine. And yes I also change split rims and put them in a cage to seat and blow them up. And I have seen a few of the Rings fly off with lots of force.

Ran a lot of those split rims back in the day, they were a bit dangerous. Yes they were always in a cage in any tire shop I was in .