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01-11-2021, 04:37 PM
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#21
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2 Rivet Member
Currently Looking...
Destin
, Florida
Join Date: Aug 2018
Posts: 24
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There is some good discussion on tires and inflation recommendations in this video at the 17 minute point. I found it useful and thought you might benefit from it as well.
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01-11-2021, 06:54 PM
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#22
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2 Rivet Member
2022 27' International
Clayton
, North Carolina
Join Date: Aug 2007
Posts: 79
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I failed to mention in my previous reply something you might want to consider. Yes, the weight ratings of your current new tires are “adequate”. Your Bambi has a single axle vs other trailers with dual axles. 2 tires vs 4 tires. That means with only 2 tires, if one blows while towing down the highway, it can be a harrowing experience. If Airstream originally installed Load Range D tires, there must be a reason. I would trust them more than anyone. It does provide additional safety factor reducing the potential loss of a tire while towing. Install a quality Load Range D trailer tire and have them balanced. It can give you greater peace of mind.
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01-11-2021, 07:27 PM
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#23
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4 Rivet Member
2021 33FB Classic
City
, West Virginia
Join Date: Sep 2020
Posts: 372
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How do I read this? I left Tampa to Atlanta with tires at 75 psi. On my TPMS - it showed all four AS tires go up to 89 psi while driving. I’m assuming I’m Single on the chart since it’s two tires per axle. But how do I read the weights? Thanks.
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01-11-2021, 08:42 PM
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#24
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Rivet Master
Commercial Member
Ravenna
, Ohio
Join Date: Apr 2012
Posts: 1,344
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Quote:
Originally Posted by Mom2twins
I have Carlisle Radial Trail HD Trailer Tire-ST215/75R14 102M 6-ply
So it looks like the max weight capacity is 1870 - if that is per tire and it's 3740 total then I'm good, if not I probably need to look at getting other tires. Although, these are literally brand new (only 2 short trips on them). I replaced what was on the trailer with like tires but didn't pay attention to load.. ugh.. baby steps.
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I doubt the tires say "6 ply" They will say Load range C or D or E
If they say 65 psi then they are LR-D.
__________________
Retired tire engineer (50 years). Write a blog on RV Tire Safety Net. Give seminars for FMCA across the US. Tucson AZ in Mar 2024 is next.
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01-11-2021, 08:45 PM
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#25
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Rivet Master
Commercial Member
Ravenna
, Ohio
Join Date: Apr 2012
Posts: 1,344
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Quote:
Originally Posted by ROBERT CROSS
Two 14" GYE's will have a bit more leeway if you do decide to up-grade.
Bob
🇺🇸
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Where do you find GY Endurance tires having greater load capacity that Carslile of the same Load range (inflation)?
__________________
Retired tire engineer (50 years). Write a blog on RV Tire Safety Net. Give seminars for FMCA across the US. Tucson AZ in Mar 2024 is next.
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01-11-2021, 08:50 PM
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#26
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Rivet Master
Commercial Member
Ravenna
, Ohio
Join Date: Apr 2012
Posts: 1,344
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Quote:
Originally Posted by AnnaBelle33
How do I read this? I left Tampa to Atlanta with tires at 75 psi. On my TPMS - it showed all four AS tires go up to 89 psi while driving. I’m assuming I’m Single on the chart since it’s two tires per axle. But how do I read the weights? Thanks.
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I believe the 7900 is the total for 4 tires on two axles. There is almost no chance that the load is evenly split axle to axle or side to side. As a minimum you need to get the individual axle readings then also apply a margin to account for the uneven load split. I generally suggest a 52/48% side to side load untill you learn the real split
Why did you inflate your trailer tires to 75. What do they say on the tire sidewall. You haven't mentioned the Load range letter on the RV or on the tires. This looks like different information that the OP.
__________________
Retired tire engineer (50 years). Write a blog on RV Tire Safety Net. Give seminars for FMCA across the US. Tucson AZ in Mar 2024 is next.
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01-11-2021, 08:55 PM
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#27
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Rivet Master
Commercial Member
Ravenna
, Ohio
Join Date: Apr 2012
Posts: 1,344
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I see a lot of information on this thread but without clearly identifying tire size, type, Load range, and measured scale load numbers. This will result in some people following incorrect and incomplete information. This can potentially create UNSAFE conditions.
__________________
Retired tire engineer (50 years). Write a blog on RV Tire Safety Net. Give seminars for FMCA across the US. Tucson AZ in Mar 2024 is next.
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01-11-2021, 09:03 PM
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#28
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4 Rivet Member
2021 33FB Classic
City
, West Virginia
Join Date: Sep 2020
Posts: 372
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Quote:
Originally Posted by Tireman9
I believe the 7900 is the total for 4 tires on two axles.
How did you inflate your trailer tires to 75. What do they say on the tire sidewall. You still haven't mentioned the Load range letter on the RV or on the tires.
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I get the 7900 on my trailer - it’s the pressures on the table. I used my ViAir to get them to 75 & they are “E” rated tires.
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01-12-2021, 06:32 AM
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#29
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Quote:
Originally Posted by Tireman9
Where do you find GY Endurance tires having greater load capacity that Carslile of the same Load range (inflation)?
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The Carslile is max is 1870.
The GYE is 2200.
I was under the impression the OP was looking for a safety margin, if not, the higher number wouldn't matter.
My experience with a single axle, more IS better.
Bob
🇺🇸
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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01-12-2021, 08:20 AM
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#30
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Rivet Master
2017 26' Flying Cloud
Tampa
, Florida
Join Date: Feb 2017
Posts: 7,653
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Quote:
Originally Posted by Hermes
I switched from the Good Year Marathons to the Good Year Endurance tires (the Marathons are no longer manufactured and the Endurance is a much better tire).
For my model, Airstream recommended 65 psi with the Marathons, which was the max pressure for that tire. With the new Endurance, Airstream now recommends 80 psi for the same trailer which is the max pressure for that tire - go figure.
So I pulled out the Goodyear "LOAD/INFLATION INFORMATION FOR GOODYEAR® ENDURANCE SPECIAL TRAILER (ST) TIRES" (see attached) and the recommended pressure for my trailer is (still) 65 psi.
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I'd like to see how you arrived at that conclusion, even thought I believe it's the correct one.
The Good Year Inflation guide for the Endurance is the same as it posted for the Marathons.
If I follow it to the letter, I get a recommendation of 30psi.
Now, I don't believe that. Airstream posts to inflate to 80 psi, and that's because it's the maximum set on the tire.
Notice the sidewall does NOT say, "Inflate to 80 psi", it says, "For maximum load, inflate to 80 psi."
So I took my weight, subtracted the tongue weight, divided by four and got 30 psi.
I inflate to 65.
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01-12-2021, 08:49 AM
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#31
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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What is so scary about PSI?🤔
I ran our GYM D's at 65 for 18 Seasons with one self inflicted curb rash failure, the GYE E's I run at 73.👍
Bob
🇺🇸
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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01-12-2021, 09:31 AM
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#32
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Rivet Master
Commercial Member
Ravenna
, Ohio
Join Date: Apr 2012
Posts: 1,344
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Quote:
Originally Posted by ROBERT CROSS
The Carslile is max is 1870.
The GYE is 2200.
I was under the impression the OP was looking for a safety margin, if not, the higher number wouldn't matter.
My experience with a single axle, more IS better.
Bob
🇺🇸
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OK then you are not doing Apples-Apples comparison. The 2200 load capacity is with the cold inflation set to 65 psi The 1870 load capacity is what you get with 50 psi.
Details are important.
__________________
Retired tire engineer (50 years). Write a blog on RV Tire Safety Net. Give seminars for FMCA across the US. Tucson AZ in Mar 2024 is next.
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01-12-2021, 11:51 AM
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#33
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Rivet Master
2015 20' Flying Cloud
Kingsport
, Tennessee
Join Date: Aug 2015
Posts: 1,290
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Quote:
Originally Posted by Tireman9
OK then you are not doing Apples-Apples comparison. The 2200 load capacity is with the cold inflation set to 65 psi The 1870 load capacity is what you get with 50 psi.
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Both are at the max psi listed for the given tire.
__________________
-Leslie
WBCCI #1051
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01-13-2021, 07:58 AM
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#34
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Rivet Master
Commercial Member
Ravenna
, Ohio
Join Date: Apr 2012
Posts: 1,344
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Quote:
Originally Posted by LNBright
Both are at the max psi listed for the given tire.
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Tires list the Maximum load they are rated to support and tires also list the minimum cold inflation needed to achieve that load capacity. I have covered this "The Maximum is the Minimum" dichotomy in my blog on RV Tire Safety.
I really do not understand why people seem so afraid of running more than the minimum cold inflation needed to support the actual load.
I am in the process of working through the "Rule Making" documents from DOT when they set the minimum margins on inflation for cars, SUVs and trucks equipped with TPMS. I note that RVs were excluded from this rule making. Could that be because the RV companies didn't want to see any increase in costs even if it meant the product would have fewer failures?
Couldn't be. No corporation would ever shave costs if the safety of the product might be compromised would they.
The MINIMUM cold inflation a tire should have would be the level needed to support the actual tire load. They also established that the normal cold inflation should be at least 25% higher than the MINIMUM. Their objective was to minimize tire failures that might result in damage or injury. The DOT knows that tire pressure increases with temperature (2% per 10F) and tire engineers know and design and even depend on this physical fact.
For some reason people with RV trailers feel it's ok to have zero margin. It wasn't till 2017 that RVIA started to require a 10% margin and some people argue that the RVIA is not a requirement. RVs built before 2017 have certification stickers that specify ZERO margin for the tire capacity was to be considered acceptable.
With the above as guidelines I have to wonder why people continue to complain about having tire failures. You are making the conscious decision to ignore established engineering recommendations and safety margin guidelines. What is so special about RV trailers that would make you think they are exempt from scientific principles and physical realities?
__________________
Retired tire engineer (50 years). Write a blog on RV Tire Safety Net. Give seminars for FMCA across the US. Tucson AZ in Mar 2024 is next.
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01-13-2021, 08:32 AM
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#35
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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^
"I really do not understand why people seem so afraid of running more than the minimum cold inflation needed to support the actual load."
Exactly....Why so shy of PSI, when under inflation is a more likely cause of failure.
I set psi with a cold tire & wheel, out of direct sun.
If you ck on the road take the hot/cold difference into consideration.
Bob
🇺🇸
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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01-17-2021, 09:15 AM
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#36
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Rivet Master
South East
, Michigan
Join Date: Apr 2016
Posts: 551
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Quote:
Originally Posted by ROBERT CROSS
^
"I really do not understand why people seem so afraid of running more than the minimum cold inflation needed to support the actual load."
Exactly....Why so shy of PSI, when under inflation is a more likely cause of failure.
I set psi with a cold tire & wheel, out of direct sun.
If you ck on the road take the hot/cold difference into consideration.
Bob
🇺🇸
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I agree. I recently changed tires and upped the load range. Where the original tires had a max inflation of 65, new ones are 80. I'm running at 80 and haven't noticed any harsher of a ride. The tires may flex less at this higher pressure, but I suspect the difference is marginal. The higher pressure doesn't turn the tires into Bedstone rock tires. I have a larger margin between actual load and tire capacity and since I'm a multi-axle trailer, lower interply shear.
__________________
Al
2017 29' SOB, 2022 Platinum F-150 SCrew, ProPride
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01-17-2021, 09:20 AM
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#37
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Rivet Master
2007 20' Safari
Old Orchard Beach
, Maine
Join Date: Sep 2014
Posts: 509
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I suggest following the specification chart on the side of the Airstream trailer, and for the tow vehicle use the chart mounted in the driver's door opening.
__________________
Marty Womer
Old Orchard Beach, Maine
Trailer name: Quarantina
2019-2022 President, Northeast Mountaineers Airstream Club
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01-17-2021, 09:34 AM
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#38
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3 Rivet Member
Berkel-Enschot
, Noord-Brabant
Join Date: Apr 2014
Posts: 243
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Quote:
Originally Posted by Mom2twins
I have Carlisle Radial Trail HD Trailer Tire-ST215/75R14 102M 6-ply
So it looks like the max weight capacity is 1870 - if that is per tire and it's 3740 total then I'm good, if not I probably need to look at getting other tires. Although, these are literally brand new (only 2 short trips on them). I replaced what was on the trailer with like tires but didn't pay attention to load.. ugh.. baby steps.
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Your tire is 1870 lbs AT 50 psi for 65mph.
Looked that back in a Goodyear list wich I know is loadindex 102. The M speedcode would mean you may use it upto 130kmph/ 81mph, but maxload is given for 65mph.
When I use my pigheaded system, I give the tire a deflection as if it was made for 99mph.
Then have to substract 6 loadindex-steps so 102 minus 6 is 96LI is maxload 1565 lbs AT 50 psi.
Times 2 ( if single axle) is 3130 lbs x 90% is 2817 lbs axleload it can support with maximum reserve, at wich still no bumping or rivets comming loose.
Now only need to know real weight on tires, second best axle, but in lack of that give GAWR and GVWR.
Why maximum reserve? Because inacuracy' of weighing and pressure-reading, you calc for that max reserve, but can end up with only yust enaugh to prevent overheating.
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01-17-2021, 10:27 AM
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#39
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Half a Rivet Short
2017 30' Classic
2022 Interstate 24X
Carlisle
, Pennsylvania
Join Date: May 2017
Posts: 15,735
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Quote:
Originally Posted by Mom2twins
I have Carlisle Radial Trail HD Trailer Tire-ST215/75R14 102M 6-ply
So it looks like the max weight capacity is 1870 - if that is per tire and it's 3740 total then I'm good, if not I probably need to look at getting other tires. Although, these are literally brand new (only 2 short trips on them). I replaced what was on the trailer with like tires but didn't pay attention to load.. ugh.. baby steps.
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Hi
Another wrinkle in this:
Carlisle tires are no longer made in the US. They are now a Chinese reseller of Chinese made tires. There are a lot of factories over there. Some are probably pretty good, some are most definitely not so good. Look up "China Bombs" and you will hear a lot about the not so good side.
Given that they could be made in one factory this year and another factory a year ago ( .... who knows ....), I would very much go with what is on the tires and *not* something you see on the internet. I also would not count on them to do well if run over pressure or over load.
Given the amount of damage a blowout can cause, I would put the best tires I could find on the trailer. That assumes it's being towed on the road. If it's just sitting in a stationary setup .... maybe not so much.
Bob
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01-17-2021, 03:11 PM
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#40
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3 Rivet Member
1960 26' Overlander
Tipton
, Iowa
Join Date: Jan 2007
Posts: 186
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I did not take the time to read through all the answers. Perhaps my thoughts have been given by others.
If your trailer says to inflate the tires higher than the tires say they can be inflated, then you were given the WRONG tires. Most likely too light a load range. I recommend you go back to the tire dealer and request the correct tires. Using a too small of a load range can lead to tire failure and a great amount of damage to your trailer...which they are not going to want to cover...so you would be stuck with an expensive repair.
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