Blown Tires and Weight questions

[Oldgator73]

Running about 60 -65. Tires were rated for 75 mph.

The reason I ask is we were traveling out west in our 5th wheel that had new tires and and tires started blowing. Since it was a triple axle I could limp into a town and get a new tires. I was at a gas station getting diesel and a guy was next to me pulling a car hauler. We got into a conversation and I mentioned the tires blowing, three by then. He asked me how fast I was driving and said between 70 and 75. He said slow down to to 55 and you won’t blow anymore tires. He was right; no more tire problems.

 

[CharlesinGA]

What does the placard on the side of the trailer specify for tire pressure? They usually use the standard charts to determine the recommended tire pressure.

That tire size and load range is no where close to overloaded. GY specifies 3420 lbs on that size/LR and that is most likely an industry standard (Tire and Rim Assn specs) so you were a thousand pounds per tire under the tire's max load capacity. The GY chart, again, based on Tire and Rim Assn standards that all US-DOT tires should meet, no matter the brand, the MINIMUNM inflation would be 45 psi (2430 lbs). My thinking is the tire may have been OVER INFLATED (at 80 psi) combined with the age of the tires and cheap off brand "China Bomb" construction, leading to disaster.

As an example, my much smaller trailer has too much tire for its size, and thus the manufacturer has placarded the trailer at 35 psi, which will support the weight, however almost everyone with this make/model trailer is uncomfortable running that low of a pressure. I started out at 65 psi (tire max is 80) and found stuff was getting beat to death inside the trailer............. Finally I reduced it to 60 and since then have settled on 50 psi. The trailer rides nice and smooth, stuff doesn't get jostled about or broken, the tire tread sits very flat on the pavement, and wears evenly (a very good indication of proper inflation)

Decorative black glass oven door front after a ride on I-285 in Atlanta with 65 psi tires.

A number of trailer manufacturers now install LT or light truck tires instead of ST or Special Trailer tires. The LT tires hold up much better (provided you can get a tire in the size and weight range you need) and most people running LT tires report no tire failures. A LT235/85R16 has a max load of 3042 lbs and a diameter of 31.7 in. Your existing size has a diameter of 30.9 inch. Moving slightly closer in height is the LT245/75R16 which also has a max load of 3042 lbs and a diameter of 30.5 inches. (there is no LT tire in the same exact size as your trailer tires)

The LT tires would be more expensive initially but would last longer. Remember, there did not used to be a ST tire. It was created to provide a standard so people would not be using underrated tires. However the ST tire is, as Gary says "...rated for much heavier loads than P or LT tires, so they are more heavily stressed".

Thats my take on it.

Charles

 

[CharlesinGA]

I did have the bearings greased a couple weeks before this trip. Very thankful I did. The metal shackles on the torsion bars were near failure. (Not sure if I used the right term - it's the metal piece connecting the leaf spring to the blue suspension bracket at about the 10:00 position in the picture) The bolt had worn through and there was only about 1/16th of an inch left before that part gave away. There would have been nothing holding the rear of the leaf spring in place at that point.

You are referring to this..........................

I cannot tell from your pic in post #1, but it looks like you replaced them with the same thin shackles. You need one half inch thick shackles installed with longer matching bolts and nuts. Kits made by Dexter, MoRyde and Lippert all do this improvement. I used a Dexter kit from etrailer. You will get greaseable bolts with the kits.

Charles

 

[CharlesinGA]

In my 50 years of driving the only brand I've had blow out were 6 Michelins that were less than 5 years old and less than 40K miles. I've had them on 4 vehicles and every vehicle had at least 1 blow out. I swore off Michelin after the 2nd RV set but the last 2 sets came from the factory on new cars. A friend that owns a tire shop said Michelins are the worst to blow out and they always look like the picture above, separated into rings. He also said they probably do fine in northern climes because he only sees it happen when the temperature gets over 100 and the tires have over 30K miles. When they go the tire causes damage to the fenders and/or inner fender wells. I'll never own another set.

I'm not sure if there is a name for this, but lets call it the "never again" syndrome. When the WT Grant's Department stores were going out of business, I bought a set of Goodrich tires (Bias Ply, common at the time) for my 1967 Ford Falcon. My dad kept telling me I'd hate them. He had bought a set of BFG Sivertowns for his '38 Buick during the war using ration coupons, and the tires didn't hold up well and he ran on slicks for a long time before he was able to replace them just after the war.

The ones I bought didn't wear well at all. Later I bought a set of BGF Radial TA's with raised white letters, for my 1970 Mustang (I still own both cars) and those lasted less than 10K mi without me hot rodding them at all. THAT second set of BFG tires were the straw that broke the camels back so to speak. Yes, BFG has been sold to someone else, and its a name only now, but I still won't touch them. Never again.....

I installed Michelin LT tires on the Winnebago View Class C and they rode much smoother than the Firestone tires that were on it. I didn't have a lot of miles on the tires when I sold the MH. My 2003 RAM that I bought had a set of Michelin Defender LT's when I bought it in 2018. I have put about 40K on the truck since I bought it and recently replaced the front tires with Michelin Agillis Cross Climate LT tires largely due to age. I will replace the rear tires later this year matching the front. The old tires are 2017 dates so its time.

Charles

 

[DonTom]

We just got back from a trip and blew 3 out of 4 tires on my Toy Hauler.

You may have beat by record on my Class C of two blow outs in two days.

I now always buy the most expensive tires they make for my Class C. Stay away from cheaper tires. Perhaps the same goes for trailers and other rigs.

So far, it does seem the more expensive tires hold up better on my Class C

-Don- Redcrest, CA

 

[Gr8bawana]

'67 Ford Falcon

 

[JudyJB]

I've thought about that going forward - increasing to a load range F tire instead.

I was just about to suggest an F rated tire. Also, average load per tire does not count--need to have no more than maximum on each tire. And you may have damaged those tires when you drove them underinflated, and it took until now for them to blow.

 

[CharlesinGA]

I was just about to suggest an F rated tire. Also, average load per tire does not count--need to have no more than maximum on each tire. And you may have damaged those tires when you drove them underinflated, and it took until now for them to blow.

See my post #22. He actually did not drive them underinflated. Using the charts to determine minimum pressure for the weight on the tires, he was just about at minimum, but not underinflated. He simply had crappy tires and 80 psi is overinflated. Hitting a pothole with a rock hard over inflated tire is not a good thing either.

If the OP stays with ST tires, they really should buy Goodyear Endurance. That size has 1000 lb of excess capacity per tire, so there is no reason to not reinstall the ST tires, just good ones. The alternative being the LT tires.

Charles

 

[CharlesinGA]

Here are ST tire size, weight, and inflation tables from Goodyear, Maxxis and Power King tires. These tables are all created by the Tire & Rim Assn and the manufacturers simply republish them. Any tire of a certain type (ie ST) from a manufacturer who obtains DOT approval will have made them to Tire & Rim Assn specifications for size, loads and pressures

Charles

Goodyear Endurance.............................................

 

[rpnelson]

We just got back from a trip and blew 3 out of 4 tires on my Toy Hauler. The first tire (front curbside) blew 45 minutes into our trip immediately after hitting a pothole. Replaced and continued. 3 hours later, the rear curbside tire blew. Replaced and continued to our campground. At the end of the week on our way home, the drivers side front tire blew (camper, not truck). At this point, wasn't taking any chances and replaced the 4th tire as well. Tires were manufactured in 2019, and on a 2020 trailer. Tread was about 1/2 worn. Inflation was at the max of 80 PSI. Tires were load range E.

Leaving the campground (tanks empty) I went to a CAT scale nearby. These are the weights:

Total Combined weight: 20,080
Truck Weight: 8,870
Camper weight: 11,210
Truck Front Axle weight: 4,680
Truck Rear Axle weight: 5,720
Weight on camper wheels: 9,680 (2,420 pounds per tire - average)
Tongue weight: 1,530 (13.64% of total trailer weight)

As the trailer was loaded, I am right at the "MAX" trailer weight as listed on the placard attached by the manufacturer. I am using a weight distributing hitch with anti-sway.

Full disclosure as to my stupidity - last summer made a 400 mile trip with under inflated tires. In getting ready, I thought the tire sidewalls were stamped with 50 PSI instead of 80. Outside of that, I have always made sure they were inflated to the full 80 PSI.

I can understand losing 1, even 2, tires after hitting a pothole. Blowing a tire on the opposite side is what really confuses me. Can anyone offer ideas on what caused such a mass tire failure on this trip? Are there things I can do to prevent similar problems in the future?

How do my weights stack up? Are there any concerns with the numbers or the distribution?

View attachment 1323594

We have experienced these tire problems for many years on numerous travel trailers and fifth wheels. RV mfgrs. use the smallest tire they can that is rated for the weight. Most of their tires are carrying 80 to 90 percent of the rated weight. They don't last long loaded like that. Most auto mfgrs. use tires carrying 70 to 75 percent of rated weight. They will last a lot longer. I have found the best way to avoid blowouts is to inflate the tires to the recommended psi for the load they are carrying. Usually it's about 60 to 68 psi. They don't last long running at max psi either. Also you should replace them at least every three years no matter how much tread is left.

 

[rpnelson]

We just got back from a trip and blew 3 out of 4 tires on my Toy Hauler. The first tire (front curbside) blew 45 minutes into our trip immediately after hitting a pothole. Replaced and continued. 3 hours later, the rear curbside tire blew. Replaced and continued to our campground. At the end of the week on our way home, the drivers side front tire blew (camper, not truck). At this point, wasn't taking any chances and replaced the 4th tire as well. Tires were manufactured in 2019, and on a 2020 trailer. Tread was about 1/2 worn. Inflation was at the max of 80 PSI. Tires were load range E.

Leaving the campground (tanks empty) I went to a CAT scale nearby. These are the weights:

Total Combined weight: 20,080
Truck Weight: 8,870
Camper weight: 11,210
Truck Front Axle weight: 4,680
Truck Rear Axle weight: 5,720
Weight on camper wheels: 9,680 (2,420 pounds per tire - average)
Tongue weight: 1,530 (13.64% of total trailer weight)

As the trailer was loaded, I am right at the "MAX" trailer weight as listed on the placard attached by the manufacturer. I am using a weight distributing hitch with anti-sway.

Full disclosure as to my stupidity - last summer made a 400 mile trip with under inflated tires. In getting ready, I thought the tire sidewalls were stamped with 50 PSI instead of 80. Outside of that, I have always made sure they were inflated to the full 80 PSI.

I can understand losing 1, even 2, tires after hitting a pothole. Blowing a tire on the opposite side is what really confuses me. Can anyone offer ideas on what caused such a mass tire failure on this trip? Are there things I can do to prevent similar problems in the future?

How do my weights stack up? Are there any concerns with the numbers or the distribution?

View attachment 1323594

We have had good luck with Hercules H901 tires.

 

[SargeW]

I recommend staying with a good ST tire. ST tires are designed to better tolerate the sideways "dragging" that occurs with trailer tires that are often lined up single file on a pair of trailer axles. A slow speed backing maneuver into a camp site that requires a tight turn to fit into the site. LT tires are never lined up in that fashion, and can just pivot on the flat contact patch of the tire on a tight turn. A triple axle toy hauler is really tough on tires as at least 2 of the 3 tires on a side will constantly be drug sideways often on asphalt or concrete.

My 5ver came with Reiner ST tires in a 235/80R/18 in Load range E. They are a Chinese tire made at a Goodyear plant in China. So far they are hold up well on my 32' fiver with 6000# axles and a GVWR of 11500#. I did rotate them once already due to front tires showing more shoulder wear on the outside edge.

 

[MoInEd]

I had my first blowout 2 years ago. Tire was E rated, 2 years old (with less than 5000km on it) inflated to 65ps for a 5000lb trailer, speed was 110km/hr and didn't hit anything. I did all the right thing and the only explanation I could find was the tire was garbage (Chinese). I inspected the other one and didn't take chances and replaced both with Goodyear (US made) ones. I think most trailers come with the cheapest components (including tires) and since there is very small likelihood that a blown tire cause personal injuries they don't care about using crappy tires...

 

[SargeW]

Some manufactures will spec tires that barely cover the GVWR and then the bean counters source the cheapest thing to fit. Trailer King tires are a perfect example of that process. They came on a new TT I had previously, they lasted a few months before they started to lose their integrity and deformed. I replaced all of them, and when the tire shop was changing them I inspected one. Picking up the carcass felt like it was made out of tire tube material instead of tread. What a joke.

 

[DouglasB12]

I was just about to suggest an F rated tire. Also, average load per tire does not count--need to have no more than maximum on each tire. And you may have damaged those tires when you drove them underinflated, and it took until now for them to blow.

I thought about this, but I have no idea of how to figure the weight load of each individual tire.

 

[Gary RV_Wizard]

I thought about this, but I have no idea of how to figure the weight load of each individual tire.

If you only have axle weight and thus only an average for each tire, you need to add a fudge factor to allow for the possibility likelihood that one end is heavier than the other. Average +10% is usually enough, but I suggest average + 20% if you are really unsure. For example, if one side of the RV is known to be somewhat heavier, you want to err on the high side. A large slideout or a big fridge on one side could do it.