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Old 07-19-2022, 06:22 PM   #41
bsmith0404
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Quote:
Originally Posted by Old_Stevenick View Post
Got this email from Keystone today. Covering their bases I guess.

Good Evening,

Thank you for contacting keystone RV. In regards to your email, below is what information I have found on your tire/wheels that should help with this inquiry.

Tire pressure - 65

Rim size: 15x6

Tire rating: 2540

Rim Rating: 2830.

Tire size: ST225/75R15D

We would not recommend changing any of these or going lower/higher as it could result in damges to the unit. If you do decide to change anything we would recommend that you have a Keystone authorized dealer or a tire center do this for you to ensure it is safe for the unit.

Thank you,


Gabriella Mahony
Digital Communications Agent
Thatís why I donít bother contacting manufacturers in most cases. All theyíre going to tell you is to leave everything the way it was shipped. They wonít recommend upgrades.
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Old 07-20-2022, 03:18 AM   #42
flybouy
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Quote:
Originally Posted by Old_Stevenick View Post
Got this email from Keystone today. Covering their bases I guess.

Good Evening,

Thank you for contacting keystone RV. In regards to your email, below is what information I have found on your tire/wheels that should help with this inquiry.

Tire pressure - 65

Rim size: 15x6

Tire rating: 2540

Rim Rating: 2830.

Tire size: ST225/75R15D

We would not recommend changing any of these or going lower/higher as it could result in damges to the unit. If you do decide to change anything we would recommend that you have a Keystone authorized dealer or a tire center do this for you to ensure it is safe for the unit.

Thank you,


Gabriella Mahony
Digital Communications Agent
Sounds like the legal dept. response. I don't know of any tire shop that will mount a tire on a rim that exceeds the capacity of the rim weight or air pressure rating. Keystone is essentialy stating the same thing that's been said here except they are in a round about way, saying have someone else verify the capacity of the rims.
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Old 07-24-2022, 08:09 AM   #43
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Originally Posted by Old_Stevenick View Post
I'm sure this has been asked and I did try the search function, but...

1650 Bullet Crossfire. 225/75/15 tires.

I bought a pair of Carlisle Radial Trail HD Trailer Tires.

Shop inflated them to 80PSI.

I'm concerned that the rims can't handle that much pressure. Should I lower them to 60 or 65 PSI?

1. What does your Certification sticker say for tire size, Load Range and inflation?
2. What does the sticker say for GAWR
3. When was the RV made? (also on the sticker)
4. Have you loaded the RV to the heaviest you expect to travel (water, propane, cloths, tools etc and learned the load on each axle?
5. What LR are your new Carlisle tires?



The above will help us give an informed answer rather than just guessing. Tires MUST be inflated with enough pressure to support the load you are placing on the tires.



I have covered how to learn proper inflation numerous times in my RV Tire Safety net blog.
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Old 07-24-2022, 08:21 AM   #44
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Originally Posted by Old_Stevenick View Post
Tire shop just told me they are "half brass" stems which are rated for high pressure.

With all this in mind, should I leave them at 80PSI or maybe deflate them a little to be safe. 70 or 75?

I strongly recommend that ALL RVs use Bolt-in metal valve stems. The "Half metal are actually just snap-in rubber that can flex or fail. When you run "Hi-Press" rubber valve stems you can end up like this.
https://youtu.be/G-R3-MNaFB4


Some will sell rubber stems that have thin chrome sleeve and try and tell you they are metal. You need to look for the hex nut and threads to know they are actually metal "bolt-in" stems.
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Old 07-24-2022, 08:28 AM   #45
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Originally Posted by flybouy View Post
Sounds like the legal dept. response. I don't know of any tire shop that will mount a tire on a rim that exceeds the capacity of the rim weight or air pressure rating. Keystone is essentialy stating the same thing that's been said here except they are in a round about way, saying have someone else verify the capacity of the rims.



To me it looks like he got the information needed. The OE tire LR was "D" which indicates 65 psi cold inflation (not the max ever seen) is what is needed to support the GAWR.


I know that not all wheels have the PSI rating marked on the wheel so the best we can do is either contact the wheel manufacturer or use the OE tire load capacity and back calculate the inflation needed to support the stated load. Ya not as good as reading a stamped number but again many wheels do not have a max load or max inflation number provided.


When a tire is inflated to the number on the tire sidewall there is not increase in inflation that will provide any additional load capacity above the number on the tire sidewall. That is the meaning of the inflation number. Some people make the serious mistake of either bleeding pressure down after driving on the tire or starting out underinflated and planning on heat generation to increase the inflation to what is required to support the load. This is a mistake and a MAJOR reason for the poor life of so many tires in RV application.
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Old 07-24-2022, 12:35 PM   #46
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Originally Posted by Old_Stevenick View Post
Attachment 40774

4400 lbs GAWR per axle.
2200 lbs per tire
2530 lbs is 15% above this.

Chart now says 65PSI.

Great info from you, thanks, but I'm still unsure what to do.
Remarkeble is the enormous reserve of the axles( 2*4400lbs =8800lbs) to the GVWR of 4700 lbs
GVWR filled in in my made extra safe calculator, and maxload tires reduced by 6 Loadindex steps, gave only 37 psi.
The 4400lbs an axle gives 82 psi with max reserve without bumping.

But I daubt you ever using axles to the max if you dont overload the GVWR.

Lets rediculesly assume 4800lbs total weight, and zero lbs on the pin. And a division between the axles 1/2.
Then one axle 3200lbs and the other 1600lbs.
Far away from 4400lbs, even the highest loaded.

To make it complete also for the D-load tires

GVWR 4700 filled in 34.psi
GAWR 4400 x2 filed in 75psi, so 10 psi more then the reference pressure of 65 psi.
GAWR filled in and 2540 lbs a tire used, so no 6 LI steps lowered, 63 psi.

I give it both, because most dont apriciate my pigheaded system.

But my idea is that even with the old tires at 65psi some screws trembling loose.

And the enormous reserves of the axles, makes them stiffer, so lesser comfort.

Weighing is the only way to be shure

But my carefull opinion is that 80 psi is not needed, and even 65 psi is, if not higly overloaded, could give screws trembling loose.
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Old 07-24-2022, 12:54 PM   #47
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Originally Posted by wiredgeorge View Post
Dave, By poking the tire expert(s), you will personally be responsible for this thread stretching to 708 pages.



Wondering what you think qualifies someone to be an "expert" on tires?


A. Having designed and evaluated tires for 40 years?
B. Having driven on tires for 40 years?
c. Having Used Google to learn about tires?
D. Listened to people complain about tires around a campfire?
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Old 07-24-2022, 01:07 PM   #48
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Originally Posted by jadatis View Post
Remarkeble is the enormous reserve of the axles( 2*4400lbs =8800lbs) to the GVWR of 4700 lbs
GVWR filled in in my made extra safe calculator, and maxload tires reduced by 6 Loadindex steps, gave only 37 psi.
The 4400lbs an axle gives 82 psi with max reserve without bumping.

But I daubt you ever using axles to the max if you dont overload the GVWR.

Lets rediculesly assume 4800lbs total weight, and zero lbs on the pin. And a division between the axles 1/2.
Then one axle 3200lbs and the other 1600lbs.
Far away from 4400lbs, even the highest loaded.

To make it complete also for the D-load tires

GVWR 4700 filled in 34.psi
GAWR 4400 x2 filed in 75psi, so 10 psi more then the reference pressure of 65 psi.
GAWR filled in and 2540 lbs a tire used, so no 6 LI steps lowered, 63 psi.

I give it both, because most dont apriciate my pigheaded system.

But my idea is that even with the old tires at 65psi some screws trembling loose.

And the enormous reserves of the axles, makes them stiffer, so lesser comfort.

Weighing is the only way to be shure

But my carefull opinion is that 80 psi is not needed, and even 65 psi is, if not higly overloaded, could give screws trembling loose.
FYI, he only has one axle on the 1650 Bullet. Not nearly as much room for error as you were thinking.
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Old 07-25-2022, 12:18 AM   #49
jadatis
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Then I was mislead by" each axle" on the plate, and per axle written by topicstarter.

Then the story becomes different.
TTmaker only put axle on with poor reserve, but original D- load to official standards 2x 2540= 5080 lbs is more then 10% reserve, but to my standards, so max reserve without bumping still 75 psi needed. And the E- load calculated 82 psi.
So E-load certainly a fiod replacement choiche.

So then 80 psi is yust needed to give maximum savety and lifetime of tires.
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Old 07-25-2022, 09:15 AM   #50
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Originally Posted by jadatis View Post
Remarkeble is the enormous reserve of the axles( 2*4400lbs =8800lbs) to the GVWR of 4700 lbs
GVWR filled in in my made extra safe calculator, and maxload tires reduced by 6 Loadindex steps, gave only 37 psi.
The 4400lbs an axle gives 82 psi with max reserve without bumping.

But I daubt you ever using axles to the max if you dont overload the GVWR.

Lets rediculesly assume 4800lbs total weight, and zero lbs on the pin. And a division between the axles 1/2.
Then one axle 3200lbs and the other 1600lbs.
Far away from 4400lbs, even the highest loaded.

To make it complete also for the D-load tires

GVWR 4700 filled in 34.psi
GAWR 4400 x2 filed in 75psi, so 10 psi more then the reference pressure of 65 psi.
GAWR filled in and 2540 lbs a tire used, so no 6 LI steps lowered, 63 psi.

I give it both, because most dont apriciate my pigheaded system.

But my idea is that even with the old tires at 65psi some screws trembling loose.

And the enormous reserves of the axles, makes them stiffer, so lesser comfort.

Weighing is the only way to be shure

But my carefull opinion is that 80 psi is not needed, and even 65 psi is, if not higly overloaded, could give screws trembling loose.
It's a rv, screws will loosen even when parked! Some of us have a few loose screws & dont have tires!
No one should be riding in the rv so who cares about the ride?
To OP! You've upgraded load capacity now inflate to use that capacity!
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Old 07-25-2022, 09:48 AM   #51
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Deflating tires creates 2 negative effects. First - more sidewall flex so more heat. Second - more rolling resistance.

NEVER, EVER DEFLATE TIRES BELOW THE PSI RECOMMENDATION ON THE VEHICHLE PLACARD.....PERIOD,
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Old 07-27-2022, 12:14 AM   #52
jadatis
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Sometimes they point to the manual, in wich for certain situations lower pressure then on the vehicle plancard is allowed. So NEVER???????

And lower pressure can have its advantages, if done within safe limits. Then still no overheated tires.

But determining weight on tires is a tricky buisines.
And inacuracies of pressure measurement, can also make it tricky.
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Old 07-27-2022, 04:44 AM   #53
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Sometimes they point to the manual, in wich for certain situations lower pressure then on the vehicle plancard is allowed. So NEVER???????

And lower pressure can have its advantages, if done within safe limits. Then still no overheated tires.

But determining weight on tires is a tricky buisines.
And inacuracies of pressure measurement, can also make it tricky.
I don't know what they do in Europe but her in the USA and I believe Canada this just not true. Please stop confusing folks with inaccurate information that pertains to the USA (& Canada) and 99.99% of this forums members & viewers.
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Old 07-27-2022, 06:23 AM   #54
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I don't know what they do in Europe but her in the USA and I believe Canada this just not true. Please stop confusing folks with inaccurate information that pertains to the USA (& Canada) and 99.99% of this forums members & viewers.
You forgot to mention the many members who are not just from the USA and Canada but from Texas!

The word "tires" in a forum topic always leads to a morass of contradictory and confusing information. If we had a forum FAQ I think the TIRES question should say:
1. If you have tires mounted on your RV in the OEM size and load rating, inflate to the value on your tire placard on the camper.
2. If the tires on your camper are a higher load rating than the original OEM tires, inflate to the PSI value on the sidewall.

I admit I am not a tire expert but all this back and forth may not be helpful for people asking a simple question.
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Old 07-27-2022, 08:50 AM   #55
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You forgot to mention the many members who are not just from the USA and Canada but from Texas!

The word "tires" in a forum topic always leads to a morass of contradictory and confusing information. If we had a forum FAQ I think the TIRES question should say:
1. If you have tires mounted on your RV in the OEM size and load rating, inflate to the value on your tire placard on the camper.
2. If the tires on your camper are a higher load rating than the original OEM tires, inflate to the PSI value on the sidewall.

I admit I am not a tire expert but all this back and forth may not be helpful for people asking a simple question.
I've followed steps 1 or 2 for well over 40 years towing about everykind of trailer & have nearly always used step 2 with only 1 tire issue, old tire that tread separated which was my fault.
Why must some make this SO complicated?
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