Replace C load-rated with D?

[jadatis]

Originally Posted by DeanAir

I have a 2015 23FB International, and I experienced a blowout this week of one of the factory GY Marathon tires. 50 PSI maximum, C load-rated. I have the factory 14-inch wheels. Is there any safety issue replacing all the ties with D load-rated tires, with maximum 65 PSI inflation? Will the stock wheels and stems handle the additional tire pressure?

If you give specifications of TT and old and new tires, I can calculate a safe highest pressure at wich no rivets pop loose.

I read between the lines here 4 tires under TT.
Need GAWR, GVWR OF TT, sise of tires , C and D load already given.

[biyak269]

1.During a blowout the remaining tire on the tandem set takes all the load, likely causing invisible internal damage. Replace both of them immediately.

2. Replace all the tires if they are over 4 years. The year of manufacture is on the sidewall.

3. Load range D tires are far stronger. Get those.

4. Don’t buy cheap tires. Get tires for trailer duty.

5. Put on a tire pressure monitoring system. It’s cheap insurance and easy to install and understand.

6. A blowout can land you and your rig in the ditch or might tear up the side bodywork of your trailer. This is from experience. Body repairs are expensive.

[kbmwrs]

And yet no one has asked...why did the blow-out happen. Seems we are very quick to blame the tire manufacturer or rating when it low pressure due to a puncture of some sort.
Stay on top of the air pressure. Meaning get a TPMS. This will warn you of lowering pressure and save that blowout that you blame the tire for.

[Tireman9]

When replacing tires it is always a good idea to upgrade to "bolt-in" metal stems.,They will last much longer, can tolerate higher inflation and will not flex when you run your TPMS. The TPMS sensors can "wiggle" and fatigue the rubber stems which may result is complete air loss and tire failure.
Metal stems are available at most auto parts stores like O'Reiley's etc. Inexpensive insurance.

Proper torque of nuts is important 25 - 45 INCH pounds is the spec.


I cover the advantages of metal stems in my RVTireSafety blog

[dgsteele]

Originally Posted by DeanAir

I have a 2015 23FB International, and I experienced a blowout this week of one of the factory GY Marathon tires. 50 PSI maximum, C load-rated. I have the factory 14-inch wheels. Is there any safety issue replacing all the ties with D load-rated tires, with maximum 65 PSI inflation? Will the stock wheels and stems handle the additional tire pressure?

We have a 2018 23FB. 15” wheels and Goodyear Endurance tire running @ 80 PSI. Rotated at 10,000 miles and rotating again this week at 20,000. No issues.

[pappy19]

Originally Posted by DeanAir

I have a 2015 23FB International, and I experienced a blowout this week of one of the factory GY Marathon tires. 50 PSI maximum, C load-rated. I have the factory 14-inch wheels. Is there any safety issue replacing all the ties with D load-rated tires, with maximum 65 PSI inflation? Will the stock wheels and stems handle the additional tire pressure?

If you want to stop blowouts, switch to LT tires and D or E rated. Historically regular trailer tires have a bad reputation throughout the RV industry, and many Airstreamers have made the switch to LT tires, the majority using Michelins. I had 3 blowouts on my GYM's, went from 15" to 16" and E rated Michelin Defender tires. That was 5 years ago and 40,000 miles, still look brand new. I also added Centramatics for true balancing. Also on my F250.

[Action]

Originally Posted by pappy19

If you want to stop blowouts, switch to LT tires and D or E rated. Historically regular trailer tires have a bad reputation throughout the RV industry, and many Airstreamers have made the switch to LT tires, the majority using Michelins. I had 3 blowouts on my GYM's,

And in the last 2 to 3 years Goodyear stopped production on Marathons. The Marathon was replaced by Endurance that have a far better load capacity and temperature tolerance. And the track record has been a rather night and day as far as failures between GYM and GYE. Do not take my word for this, search these forums for owner feedback.

Using a ST GYE is a far less costly tire replacement solution than increasing wheel and tire size to get the extra capacity and added margin. Or moving up a load grade in a tire like from D to E.

Action

[pappy19]

Originally Posted by SilverWind

I replaced the 14 inch with 15 inch Sendel T03 wheels on my 2014 23RB. Mounted Michelin 15 inch "D" rated tires. This has been a common retrofit of the 14 inch 23FB/RB trailers.

Probably the best fix even with the newer trailer tires from Goodyear and others. LT tires seem to way outlive trailer rates tires without the blowout issues or rates.

[Tireman9]

Originally Posted by biyak269

1.During a blowout the remaining tire on the tandem set takes all the load, likely causing invisible internal damage. Replace both of them immediately.

2. Replace all the tires if they are over 4 years. The year of manufacture is on the sidewall.

3. Load range D tires are far stronger. Get those.
What makes you think LR-D tires are "far stronger". The difference in load carry capacity is based on the tire inflation not on the construction. It is entirely possible that the only difference is the bead wire. I know this was true for a tire I designed (LR-D > LR-E) The bead bundle was the "weakest link" for the pressure increase so that was all that needed to be changed.


4. Don’t buy cheap tires. Get tires for trailer duty. Yet almost everyone shops on price

5. Put on a tire pressure monitoring system. It’s cheap insurance and easy to install and understand. Totally agree

6. A blowout can land you and your rig in the ditch or might tear up the side bodywork of your trailer. This is from experience. Body repairs are expensive.

Maybe if more people read THIS post and took the time to understand the real reason WHY a tire failed there would be fewer tire failures out there. BUT it's always easier to just decide the zip code of the factory where the tires were made is the reason for the tire failure than to take the time to learn and understand. Also how many of you that have had a failure ever bothered to file a complaint with NHTSA?.

[Tireman9]

Originally Posted by pappy19

If you want to stop blowouts, switch to LT tires and D or E rated. Historically regular trailer tires have a bad reputation throughout the RV industry, and many Airstreamers have made the switch to LT tires, the majority using Michelins. I had 3 blowouts on my GYM's, went from 15" to 16" and E rated Michelin Defender tires. That was 5 years ago and 40,000 miles, still look brand new. I also added Centramatics for true balancing. Also on my F250.

Many seem to forget that an LT tire of the same size as their St type tires has a 10 to 20% lower load capacity so just switching tire type and not confirming actual tire load and actual tire capacity, may be the reason for the failure

[BayouBiker]

I Completely agree tireman. Blanket statements about switching from an ST (Trailer)to a LT (Light Truck) tire does not guarantee you a more durable and better performing tire, even when the specs are comparable.

The keys are maximum actual load capability, resistance to temperature build up, sidewall scuff resistance, ply construction and tread pattern. Better quality ST tires are durable and specially designed for towing.

There are clearly some poor trailer tires in the market and they should be avoided, but too there are some poor LT tires also. I urge everyone to look first at high quality ST tires, like the Load Range E 87 mph speed rated Goodyear Endurance. They are considered by many experts to be superior to equivalent LT tires in performance and durability on trailers.

[batman]

Ditto to BayouBiker's comment.

Expert advice from industry professionals is hard to argue with, right?

"Tires fail from two basic causes.

Low air pressure
and/or
Long term degradation of the rubber usually from excess heat."

Substantiated facts. Not myth, legend and folklore.

Thank you Tireman9.

-Dennis

[Action]

Low tire pressure generates heat.
The lower the pressure usually more heat

>>>>Action

[jadatis]

In Europe TT 's have LT tires ( called C- tyre , Eur eqivalent) . Sometimes " for trailer use only" with speedcode N , and realy calculated in maxload for 140kmph/87mph., so 2 Loadindexsteps higher then same specifications C- tyre.

Official institutes like VACO and ANWB in the Netherlands advice yearly checkup bij specialist after 6 years of use, and preventively replacement after 10 years of use. 2 years of profesional storing can be sold as new tire.
This could sometimes mean 12 years after DOT date replacement.

Only BOVAG , who represents garages, stays to 6 years renewal for TT tires( comercial interest) . Yeaterday I sended them a mail that they have to talk to VACO about chanching their Policy.

[Tireman9]

It's no longer 1970 with a National 55 mph speed limit with ST tires being introduced i.e. "pushed" by a large tire co, as an alternative to the real LT truck tires of the day. I have been told that one of the "selling points" for this new type of tire was that no one would ever pull their 15' trailer faster than 55 with their bumper hitch.
Well times have changed. We now have '1-Ton" Diesel Pickups that can pull a 35' trailer up the side of a mountain and run 75+ all day long. Trailers now come with two bathrooms, residential refrigerators and two AC units.
What hasn't changes is the fundamental science that a tire's load capacity is still basically "Load = Air Volume x Air Pressure". Yes materials have improved and radials are better than bias tires but basically all these "improvements" delivered is longer life and better fuel economy and tread wear. Some construction features such as the addition of Nylon cap strips or full cap ply have allowed an increased resistance to the heat from higher speeds but I haven't seen any increase in load capacity in either Passenger or LT type tires over the past 40+ years.
As I have posted on my RVTireSafety blog "Where is the Magic" and why haven't tire companies increased the load capacity of P and LT type tires if all these "improvements" are available?
What "feature" is in ST type tires that gives then the +10% to +20% more load capacity over an LT tire of the same physical size?
IMO there is no reason why RVs could not be supplied with LT tires other than it would increase the cost of the tires to the RV company. We all see numerous posts from some who are running truck 17.5 size or LT 16" tires with improved durability so i see no reason to believe that the entire market could not benefit from a switch from ST to LT type tires.
One thing is certain is that the LT tires that have to meet the new DOT standards that were introduced in 2002 are probably more durable than the ST tires that are still only required to meet the standards on the 1970's.


I am not saying that some of the newer ST tires with newer construction are not significantly better than the same size tire from the 90's but IMO there is still a limit.

[Wazbro]

Originally Posted by Tireman9

What "feature" is in ST type tires that gives then the +10% to +20% more load capacity over an LT tire of the same physical size?

Oh, I know this one.

Lower Speed Rating.
For decades most LT tires had a speed rating 95mph or more while until the GYEs most ST tires had a 65mph speed rating.

So same size; higher speed=less load for same heat buildup.

[jadatis]

Reply to above

Also the Endurance is calculated in maxload for 65mph, max allowed speed acording to speedcode is not always the same as the speed , the maxload is calculated for.

Normal car tires up to V , give maxload for 160kmph/99mph. W 190KM/118M/H max 270km
Y 220KM/ ? M/h max300km
So for those its normally accepted.

[Tireman9]

Originally Posted by Wazbro

Oh, I know this one.

Lower Speed Rating.
For decades most LT tires had a speed rating 95mph or more while until the GYEs most ST tires had a 65mph speed rating.

So same size; higher speed=less load for same heat buildup.

Yes Wazbro You are correct. You win the Junior Tire Engineer badge along with all the rights and benefits thereof.