Trailer tires

[Dan Phariss]

According to
http://www.goodyear.com/rv/products/..._wrangler.html
The Wrangler HT is OK for use on bumper pull travel trailers. This gives an alternative to the Marathon and also allows the use of a tire size that duplicates the diameter of the 700x15 that came on my 73 Ambassador.
The 225/75R15 is a smaller diameter tire.

Any thoughts?

Dan

[Inland RV Center, In]

The sidewall construction of the Marathons are stronger. Additionally, the rubber composition of the Marathons reject more UV, and therefore last longer in the sun. Andy

[Dan Phariss]

I appreciate you posting here and respect your experience. However, I have to play devils advocate here so bear with.
How is the sidewall stronger? I have not done a lot of talking to the tire guys around here but the two I talked to didn't think there was a significant difference. Other than the trailer tires are harder to balance. Something that comes up again and again when dedicated trailer tires are mentioned. To me this means that someone is not properly engineering the tire or it suffers from being thrown together in a haphazzard way "since no body balances trailer tires anyway".
The only "light" radial tire I know of that actually advertises stronger sidewalls is the BF Goodrich All-Terrain and Sport Truck T/As with a 3 ply carcasses. They specifically say their sidewalls are stiffer and promote better handling and resist sidewall damage. Claims that are not mentioned in any of the trailer tire specs.
I am irritated that that I am required to give up about an inch of tire radius to run radial trailer tires assuming 225/75R15. This means giving up ground clearance, important some places I will be going and I will surely need to modifiy the hitch to level the trailer with the truck I am going to tow with.

If I go to a 225/75R16 I can maintain about the same diameter as the 700-15 and could run radials with the same 75 profile as the trailer tires. Which I believe is the the primary reason all the radial trailer tires are 75s rather than 85 or 82 ratio tires. They control squirm not by significantly stronger sidewalls but by making the sidewall shorter. This is how sidwall squirm is controlled in automotive tires and why the sidewalls have gotten lower on most car and light duty tires.

Then I find the Champion Trailer site that seems to recommend only bias ply for trailers.

I'm sorry but everytime I see a 2 ply sidewall tire being claimed to be stiffer and then I find a manufacturer who has actually stiffened the sidewall by going to a 3 ply sidewall my bullshit detector goes off when I get told that this 2 ply tire is stiffer than another identical 2 ply tire and thus the 2nd tire cannot be run on a trailer. I would like to run Toyo or Yokohama 700r15 lr E highway rib but figure the high sidewall may indeed reduce resistance to sway.

I consider the UV claims to be pretty far down the line in importance.
Sorry to take up your time but I have been trying to get some kind of actual technical answer to this for about a month now and I am getting close to buying tires.

I DO know you can split rims by running stiffer tires/higher inflation pressure and tear out centers. Tandem trailers especially are hard on wheels. I need new wheels too so thats why I am thinking of 16 inch even thouigh they are more expensive. Marathons are made in a 235/80r16 but its a little too large.

Dan

[Action]

So Dan here is my nickel's worth of thoughts on tires.

I am in the process of replacing tires on my truck and trailer and have gotten a little education.

There is some corrallation between stiffer and stronger however they are not interchangeable. For example a radial tire may have more plies and be stronger and the bias ply tire can be stiffer. Then there is the intended use. The letter in front of the tire size says a lot about the tire. Example:

P = passenger tire -- run of the mill light duty tire. Can be many sizes and different plies. Load range B (or a 4 ply tire)

LT = Light truck tire -- Stronger tire and can handle higher loads than a passenger tire. (like a load range C or D which is a 6 or 8 ply rating)

ST = Trailer tire only. Generally stiffer than the above tires and is not rated for vehicle that carry people! Usually carries biger loads than passenger tires.

The actual load rating is now stamped on the outside sidewall of the tire assuming max inflation. This is because in the old systems a tire could be manufactured with less plies (ie less cost) and at a higher ply rating or higher letter grade. So it was difficult for a consumer to determine what the need. --- "I want a 8 ply tire!" "OK Mr. Consumer, however here is a 6 ply tire that is as strong as a 8 ply one" Confusion!

Then there is bias ply vs radial. Bias ply is stiffer than a radial. The load rating can be the same however the tire sidewall will not flex as much and will offer a harsher ride. (Not to mention a bias ply is not as fuel efficent due to rolling friction which is a whole different discussion) And bias ply tires were the only choice for any vintage A/S trailers.

So with all the choices it is best to know what the max load that you are carrying (and build in a safety factor above the max load) and get the tire that will not only fit the wheel well, and also have the capacity. And realize that when your silver bullet was made the tire sizes and choices were much different. However the load requirement that is needed is is still the same.

This is by no means a complete analagy however it should get you pointed in the right direction.

>>>>>>>>>>>Action

[uwe]

I just put on 4 new tires on my 71 Tradewind, got them from a local dealer here in Orange, CA. Towed the trailer to San Felipe, Mexico the next day. The tires worked in a most excellent way. I simply asked for 7x15 bias ply trailer tires, which is what the manual states. They recommended Carlisle tires, which still make this strange size. The tires look funky, have really tall, but very strong sidewalls, and seem to handle very very well. I do not, however have a lot of experience towing trailers, so I am not one to spread wisdom, but this was a good experience to share, I thought.
We'll see how they wear in the next year or so, but so far so good. The roads in Mexico are often very challenging, and temperatures go over 100F 200 days a year. Add to that strong winds, and you have a trailer eating environment. But our 25ft. tradewind with it's ugly new tires pulled very very nicely.
The tires took well to deflating for going through sand on the beach as well. We deflate to about 15 lbs, van and trailer, and never get stuck. ( Nothing like an airstream right on the sand of a desert beach!!)
Uwe

[Action]

U,

Welcome to the forum!

Carlisle tires are trailer tires. They will serve you well! I would recommend that you keep the tires covered from the sun as much as possible. Most trailers tires will develope side wall cracks and leaks from the sun and elements a long time before the tread wears down.

Also proper inflation is very important. If you are traveling with the heat it is best to ck and fill early in the morning when the tires are the coldest.

>>>>>>>>>>>>>>>Action

[uwe]

Dear Action,

They recommended 50lbs at the tire place for the bias ply trailer tires. I inflated to 55lbs in the
middle of the day, and when I came back to Cal. and checked, the tires were at appr. 46-48 lbs cold. I guess that's ok.
My trailer has a mooulding above the wheelwells, looks like an awning rail, on both sides. Could those be for sun protection for the tires? I have never seen these on other trailers.

Thanks for your reply, Action, and the welcome note. I am very new to airstreams, actually trailers, period. It seems that this forum has a lot of good information, making it easier for me to keep a 30+ year old device.

Uwe

[Pahaska]

Is Carlisle Tire & Wheel Company today the same company that was building tires in Carlisle, PA back in the 1940s?

My dad worked for an outfit that serviced big electrical motors. He would often get a weekend trouble calls to Carlisle Tire and take me with him for company. In those days, they had a "black room" where they mixed carbon black with the rubber (real rubber in those days). The air was always floating full of carbon black and I was forbidden to go in there. It was said that you could "walk into one door a white man and come out the other door a black man."

Every time I see a Carlisle Tire sign, it brings back a lot of memories, even if it is not the same company today.

[Action]

Double check the sidewall of the tire for max inflation. And do not exceed that pressure when tires are cold. During a hot day when traveling the tire pressure will go up. Do not let out (bleed) any air.

I have seen rails over the wheel well on some trailer to attach a curtain for sun protection. This is what you may have. If you can take a pic and share it the rest of the forum we may help in that area.

>>>>>>>>>>>Action

[Dwight]

This past March, I put 6 of the Cooper ST tires on our 34' Excella. I have used Cooper tires on my other vehicles and have had good luck.

[CPRcubed]

I also run Cooper 7.00x15 ST tires on my 25ft 1971 A/S. They have worked well for me. Yeah, they aren't the most attractive things, but they are stout! Cheers!

[Fatt Ratt]

Hey y'all,
I run Winston Hi-Ways, 7.00-15LT, Load range C, 6 ply rating, from Winston Tires. These tires have tall side walls and retain the look of the 70's. They are stout and pull very well.

[91Excella]

Just to add my 2cents worth on tires. I have been using 4 DUNLOP LT235-75 A/P 15 inch E series Radial tires on my 26 foot 76 Argosy TT for many years with excellent results. The load range of these 8 plys is such that if I were to get a flat 2 of these tires would safely support the weight of the trailer, though I don't know how the axle would fare. The side wall stiffness is plenty beefy to eliminate tire sway, and the ability to put 65LBS of air in if I choose is a fine tuning plus, though I find 45 to 50 LBS to track and brake better with a normal week-end load. Since the major tire manufacturers generally agree that tires over 7 years old are unsafe due to rubber degeneration from the "inside out", where UV attack is not a consideration, as I have read in Trailer Life many times through the years, I do not feel that the extra UV protection supposedly built into ST tires is really a relevant factor, since a quality truck tire shouldn't "check" on the outside before that anyway, with proper inflation and reasonable care.

[davidz71]

The tires that came on my '77 Excella 500 when it was picked up in AZ. May '01 were thought to be a little over one year old. They had plenty of tread left on them and were passenger car tires. They had around 60 lbs. of air in them when one of them on the curbside let go at 62 mph on the interstate just west of Amarillo, TX. I felt the vibration, looked in the side mirror and saw pieces of tire and insulation floating in the air. Use of car and truck tires is an invitation to a blowout sooner or later and you won't like the metal fabrication work that has to be done to make it right. I limped into Amarillo, TX. and had 4 new Carlisle ST D rated tires put on. I hope I never have to go through that again.

[uwe]

I can imagine that a 31 foot Excella would shred car tires inflated to 60lbs, especially on Hwy 40 near Amarillo. America's worst Interstate.
I lost 2 BRAND NEW e-rated truck tires near Amarillo, one 40 miles east, the other 30 miles west of Amarillo. On a Sunday late Afternoon. I was not towing, but carrying a heavy load in my van.
Using e-rated truck tires on a sub5000 lb trailer in my opinion is not ideal, but I don't think it's unsafe. I do see a lot of trailers on the road with passenger car whitewalls, which I believe is entirely unsafe.

[uwe]

I had an interesting experience with the Carlisle tires that I purchased earlier in the year.
While safety checking my brakes and bearings, I noticed one of my wheels acting like a swinging pendulum, coming to a rest slowly. I turned the wheel/tire assembly a few inches, let go, and the same thing happened. Turned it the other way, with the same result, being that the tire would come to a stop in exactly the same place. So I took it off, took off a tire from the other side, and headed for my tire dealer's shop.
It took ELEVEN ( that's 11) ounces to balance this tire/wheel assembly.
we dismounted the tire several times, moved it on the rim, but never got below 6 or 7 ounces to get it in balance. Then mounted the tire to a brand X light alloy wheel, checked the balance, and again came up with unusually high balance weights. I took back the wheels, mounted them to the trailer and drove around for a while with the trailer in tow, back to the tire dealer, this time with warm tires. They checked the balance on all 4 wheels, with very poor results. ( This is not the dealer where I originally purchased the tires) It was close to impossible to get the tires to balance on a spin balancer to get to where the readings were "0"
It took several hours and lots of lead to get the tires to a semi balanced state.
I will buy new tires soon. I will buy Marathons, and I will use my reputable tire dealer to install them and balance the wheels. I thought I got a good price on the tires, but i actually bought trouble. Marathons are available online for less than $70.00 each. I paid more than that for an obviously inferior product. Just thought I'd share this with the forum.

[davidz71]

Uwe,
Everyone seems to like the BFG All Terrain Radials around here even if they cost more. I had all kinds of problems with the older style BFG tires when it came to sidewall cuts. I lost 2 tires this way. I guess any company may put out a bad tire once in a while. I have the Carlisles with over 3500 miles on them so far and recently checked each tire to be sure the bearings/tires were spinning freely. Everything seemed to be fine with no uneven treadwear. I will repack bearings the beginning of winter.

[overlander64]

I have had exceptionally good luck with every set of Good Year Marathon radial ST tires that I have owned. Both my '64 Overlander International, and Argosy Minuet are currently riding on Marathons - - P225 75 R15 Load Range D on the Overlander, P225 75 R15 Load Range C on the Minuet. The Overlander has been all over the western US with its current set dating to 1999 with about 20,000 miles of travel - - they are rotated and balanced at the beginning of each season when the wheel bearings are packed. When I purchase the Minuet in August, there was no question in my mind - - it too received a set of new Marathons. I will admit that the decision is easier since I have been buying tires from the same Good Year dealer for more than two decades with absolutely fabulous service.

The only unsatisfactory set of Good Year tires that I have ever owned were the bias-ply Marathons that came as original equipment on the 1980 Nomad that I purchased new. Those tires lasted less than a year, but my Good Year dealer made a good-faith (I don't think that the factory reimbursed him for the adjustment) adjustment on the tires (the same dealer that I still patronize).

Kevin

[53flyingcloud]

Just wanted to give another input. I've used on the A/S TOYO tires for nearly 4 yrs now with excellent results so far. The side walls still look excellent and like new..The tread depth is still almost like new. This with over 14,00 mmiles on them..I;m in awed of the life expectancy so far, it's been a decent tire.
this is a picture of what they looked like abt two weeks ago.
btw, Andy...you can see the top of the Wheels toooo.. lol

[91Excella]

My understanding from talking to a gentleman at Cooper Tire who their Customer relations folks brought in especially to answer my questions and who actually builds tires and is also a trailerist is that safety-wise you can use either the LT or ST tires if the load range is correct for your application.
The LT Tires have a greater variety of sizes and tread patterns to select from to suit special concerns you may have for snow or off-road use.
The ST tires are a hybrid of Light Truck Tire fabric components and load capacity and Passenger Car Tire construction and shock absorbing ride. ST tires are also put together with a special rubber additive designed to resist UV deterioration when sitting parked in the off-season.
ST Tires are indeed "Special Trailer". The are specifically designed to protect the trailer chassis and body components from road shock, with a very strong but also importantly very flexible sidewall, they are as capable as a LT tire load wise and carry the same load as a LT Tire but at a lower, less punishing air pressure.
I am currently running Goodyear/Dunlop LT 235-75R 15D tires on my 26' Argosy, but plan on going with the Cooper ST Tires next time, to take some of the stress off the trailer components.