RV Tires

[Chilliwack Murray]

Like most things, the truth usually lies somewhere in the middle. There are too many variables to put a definite number of years on tire life and tire shops have a definite interest in giving you a worst case number. Around here they have been lobbying government to impose end of life laws for car tires - they want police to ticket if you have a car with tires more than 5 years old. Awfully good for tire shops but not very good for a senior with 15k on their garage kept Buick whose tires should easily last 10 years or more.

Heat is the main enemy of tires and a high quality tire will be damaged in minutes due to overloading or under inflation and may still run many miles or years before it fails outright. If you don’t know the history of your tires, be extra cautious.

A tire not abused or subject to excessive sun or heat should last 10 years minimum but initial quality plays into that also and is pretty hard to determine externally. Once tires develop cracks extending beyond the surface they allow sand and grit to enter which accelerates the wear and will damage the cords. Usually tires separate rather than blow out though most people don’t notice the separation and continue driving until they do blow out.

Inspect your tires carefully and replace when there are signs of damage. You can’t hear or feel a trailer tire beginning to fail like you can on your tow vehicle. Your only indication of condition is temperature. Get an infrared thermometer and keep track of temperature keeping in mind sun and road temps. Tires follow a temperature pattern and when one starts to vary from the pattern there is an issue to investigate.

[floyd]

Passing a law like that would be inadvisable.It would only mean the end of development of longevity in tires.
Tires would then be built to fail in five years and folks like Firestone (circa2001) could build shoddy products with impunity.


Nobody would then have the incentive to build a better tire and the politicians could get fat off the kickbacks from the tire company's excess profits.
Great plan!


Oddly enough, tire build dates are often stamped or placed only on the inside side of the tire. It would be kinda rough for your local LEO to crawl under the car in the mud, gravel or ice and snow just to collect a fine or harass decent citizens.


Besides in "BC" tires are made of stone...
and are often taken for "granite"

[steve dunham]

When Casita used C rated tires the conventional wisdom was to upgrade to D rated tires . When Casita shifted to using D rated tires on their trailers , the new mantra was to upgrade to E rated tires . The GVWR never changed and remained at 3500 lbs . I would venture that if Casita went to E rated tires , people would then suggest going to F rated tires
Never made sense to me but bigger is always better seems to be a common and unfounded philosophy .

[floyd]

Originally Posted by steve dunham

When Casita used C rated tires the conventional wisdom was to upgrade to D rated tires . When Casita shifted to using D rated tires on their trailers , the new mantra was to upgrade to E rated tires . The GVWR never changed and remained at 3500 lbs . I would venture that if Casita went to E rated tires , people would then suggest going to F rated tires
Never made sense to me but bigger is always better seems to be a common and unfounded philosophy .

[Roy in TO]

Originally Posted by Jared J

Well, I have a reply from maxxis. I'm quite surprised.


Jared,
According to the Tire and Rim Association the inflation pressures and load specifications in general for any ST Radial trailer tires, regardless of the manufacturer, are designed and rated at 65 MPH. However, if the speed is higher than 65 MPH, the pressure and load need to be adjusted according to the following guidelines:

Things seem to have changed over the years, the Carlisle Radial Trail HD I just purchased are rated to 81 mph.

Originally Posted by steve dunham

When Casita used C rated tires the conventional wisdom was to upgrade to D rated tires . When Casita shifted to using D rated tires on their trailers , the new mantra was to upgrade to E rated tires . The GVWR never changed and remained at 3500 lbs . I would venture that if Casita went to E rated tires , people would then suggest going to F rated tires
Never made sense to me but bigger is always better seems to be a common and unfounded philosophy .

I just upgraded to a D rating with the Radial Trail HD. It upgrades the load from 1360 lbs to 1570 lbs. I was not concerned about the capacity as both exceed the weight of my Trillium 4500. I did consider that going from the 6 ply rating equivalent to 8 ply would give me a better sidewall performance.


I considered that trailer tires are generally made for all types of trailers. A low utility trailer loaded would experience different lateral forces than our much taller campers.


Sadly we lost our tire engineer Steve L a few years back and Brian B-P is no longer active in the forum. I'll have to reach out to Carlisle, like Jared did with maxxis and see if I can get a current tire inflation chart for their tires. All the charts I've found so far only list a single 175/80R13 which I would have to assume is a load range C.

[Glenn Baglo]

https://www.carlislebrandtires.com/o...dial-trail-hd/

[John in Santa Cruz]

what we really need is the table for each tire size that gives weight vs pressure.

for example, a Carlisle ST205/75R15 load range 'D' tire has a 2150 lb rating at 65 PSI. If it has, say, a 1600 lb load, then what should the pressure be? These tables have become very hard to find.

[Iowa Dave]

Originally Posted by John in Santa Cruz

what we really need is the table for each tire size that gives weight vs pressure.

for example, a Carlisle ST205/75R15 load range 'D' tire has a 2150 lb rating at 65 PSI. If it has, say, a 1600 lb load, then what should the pressure be? These tables have become very hard to find.

I’ve not looked for a tire table other than one for the Goodyear Endurance tires that we run. I googled Goodyear Endurance tire load and it came right up.
Iowa Dave

[Roy in TO]

Originally Posted by John in Santa Cruz

These tables have become very hard to find.

This page https://weekendrvadventures.com/rv-tire-pressure/ has links to charts for Goodyear, Michelin, Bridgestone/Firestone & Maxxis.


It says that "Carlisle (Only Warranty Tires Operated at Max Pressure)"


I have reached out to Carlisle about their load charts or recommended pressure for my setup. I will post if/when I receive a response.

[Roy in TO]

Carlisle responded.

The air pressure that you need to keep in your tires are 65psi. It does not matter the load should always be at 65.

65 psi is the max pressure in their literature and specs for my tire. Also what is on the side of the tire.



Your Carlisle tires may have a different maximum which will be on the tire itself.

[AlanKilian]

My Karrier ST175/80R13 8 ply Load D tires are rated at 1,650 pounds each at a maximum pressure of 70 PSI.

I run them at around 40PSI because at 70 PSI the trailer bounces around and I feel it's not safe to drive it that way. I check them at every stop and they are never even warm to the touch.

And I have a 2 year old Flexiride axle so I'm sure the axle is just fine.

It's (in my opinion) just that this mostly-empty 1977 13' Scamp weighs close to nothing and having 3,300 pounds of tire load rating (for a what, 1,800 pound trailer?) just makes the tires too stiff for this usage.

People can disagree, and if you really think I'm being reckless, then that's the way it'll have to be I guess. (And no, I have not weighed my trailer. Come at me with your scale if you want.)