Load C to load D tire inflation?

[lawrosa]

So I have Jaxxon tires now on the RV. Rated 81 mph load C @ 1760 each.

205/75 r14 @ 50psi

Note: Im not upgrading rims, tires to 15". No way. Cant afford it.

The tires are ok. Seems wear for only 5000 miles is a bit off if you look at the tire. You say in your mind and ask the question to knowledgeable people , " Do these tires look right to you?"

So to replace of course not going with jaxxon... But choices seem to be something like

Taskmaster load C. Has 2 year warranty and 81 mph rated 70 bucks

Westlake load C. 5 year warranty (wow) but a 75 mph rating. 80 bucks.

Now I do like the endurance tires from GY. But they only come in load range D. These are 65 psi tires.

If I went this route I dont want or need the capacity. Its a 7000 GVW trailer maybe loaded to 5500 lbs max fully loaded. Lets just say I can get it up to 6000 lbs for giggles.

Also note the dry weight was/is 4730lbs. No way to fit close to 2200 lbs in any of the available storage areas.

So GY inflation tables shown here show I can do 50psi for the same 1760lb rating as c rated tires.

GY endurance inflation tables.

The question. How will lower PSI affect the tire regarding heat?

I was thinking maybe running 55 psi in them. But I dont want the trailer bouncing all around.

Thanks in advance.

[mike-s]

For ST tires, there are load/pressure tables to follow. It's not just inflating to max sidewall pressure. And, those tables apply for the standard 65 mph speed rating. But, ST tires can be run faster - add 10 psi (but not over max, so the effect may be to derate the load) and you're good to 75 mph. Also derate the load by 10% and you can go to 85 mph. That's for all of 'em - specs from the TRA Year Book, the industry "bible."

Manufacturers are able to exceed the standard ratings, so there are tires out there with higher speed ratings at the standard load/inflation. If load range C will handle your load, so will LR-D at the same pressure. But if you're near the max load for an LR-C, a LR-D will let you add 10 psi and increase the speed rating.

[Lwiddis]

“I know for a fact that I inadvertently ran my trailer curb side tires up on the curb on several occasions ”

Who in China was at fault, Sound guy?

[lawrosa]

I get so tired of people bashing Marathon tires. You'll never know how an owner treated them, even if they claim they did all the right things. To get reliable and decent service life from any ST tire, you need to stay under 65 mph (unless tires are rated higher), never tow overloaded, never tow under-inflated, stay off road shoulders and avoid sudden/hard speed bumps and potholes.

As I sated before. I ran the marathons on a used trailer I bought for two years.They were original with the RV.

12 years old.:E

I liked the marathons.

The guy only used the trailer 1 week a year to go to the car show in PA.

I changed them to the Kendas when I saw minor dry rot cracking and I had a rotted valve stem. Tire went flat sitting at campsite..





New rims /tires

[SoundGuy]

myredracer wrote:
To get reliable and decent service life from any ST tire, you need to stay under 65 mph (unless tires are rated higher), never tow overloaded, never tow under-inflated, stay off road shoulders and avoid sudden/hard speed bumps and potholes.

I know for a fact that I inadvertently ran my trailer curb side tires up on the curb on several occasions when pulling up to the house and although I can't say for sure whether that had anything to do with one of those tires failing the tire that did split and had a large delamination bubble inside was one of those curb side tires, not the street side. I'm being a LOT more careful these days with my new Endurance, remembering the trailer has a wider track than the truck and will climb the curb if I pull to closely to it. :E

[myredracer]

The psi ratings of the new ST Endurance tires has def. caused some confusion out there. These posts about the Endurance tires on the RVtiresafety.net blog here, here, and here. are a MUST read.

What's important is reserve load capacity to reduce heat which will reduce the risk of a blowout. The more reserve load capacity you can get, the better - not a good idea to reduce it unless you had plenty to start with. This is why it is always a good idea to run the tires at max. sidewall psi. I'd run the tires at the highest psi you can (to their max rating) and harsher ride isn't a concern. The higher psi should give better handling/stability IMO on twisty roads or making sudden lane changes.

End of next season I plan to replace our then 5 year old Marathons with the new Endurance tires which for the same width would be LRE. That would mean for our TT, going from 65 psi to 80 psi. I do not know if our rims can handle higher pressure and haven't pulled a wheel off yet to see if there is a rating stamped on it. The solution is to simply run the tires at the LRD psi of 65 psi. We ordered the optional LRD Marathons over KZ's standard LRC tires when we bought our TT and already have much higher reserve load capacity than KZ's standard LRC tires and running LRE tires at 80 psi to get max. load rating is unecessary. If our rims can handle 80 psi, I'll run them at 80.

I get so tired of people bashing Marathon tires. You'll never know how an owner treated them, even if they claim they did all the right things. To get reliable and decent service life from any ST tire, you need to stay under 65 mph (unless tires are rated higher), never tow overloaded, never tow under-inflated, stay off road shoulders and avoid sudden/hard speed bumps and potholes.

[Atlee]

And of course the original Goodyear Marathon was a terrible trailer tire, especially after GY moved the production off shore.

So previous bad reviews of the older Carlisle tires should attach in anyway to the new Carlisle HD tires.

time2roll wrote:

lawrosa wrote:
https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

What other tires are recommended here? I read something on maxis tires?

I think something has changed at Maxxis. For many years they were bullet proof, the real go to quality tire. So I bought some about five years ago and just short of four years the tread cap was coming off. Lucky to spot it just before a trip. For the last couple years the reports of Maxxis issues have been trickling in. Still a good tire but I had to move on and went with Endurance rated 87 mph. Carlisle HD seems to get good reports with the new improved tire but previously they had many reports of failure. That is my perception and summary of anecdotal evidence.

Also the Kumho 857 has received good reviews and is well recommended for 14". I believe it is a an LT style tire but comes at a bit higher price. Shop around.

[2112]

A few months ago I was where you are now except with 15" D rated tires. I decided on the Endurance E rated, aired to 85 PSI and all metal bolt-on valves. I left the tire shop and didn't get 10 miles down the road before I pulled over to let air out. At 85 PSI they were hard and bouncy.

I now travel at 68 PSI and they are smooth as glass. I will find out if heat becomes an issue this summer. I don't tow faster than 65 so I doubt it will.

[lawrosa]

Just some more tid bits


Those were not my actual trailer tire pics above. But maybe tomorrow Ill get a pic of the actual tires so you all can see what 5000 miles has them looking like..

Im really pissed now. Im looking at kenda karriers that I had put on my onld camper. I thought they were good. But just the 3 years ago I did that they were only 65 mph tires..Although only 13"/..

Now looking what they offer in my 205 74 14 they show an 81 mph... ok good..

But low and behold, a 60 psi tire with a 1900 lbs rating....

What gives!!!! with this psi nonsense..

I also been reading and it would seem the PSI dictates the speed rating.. So if I lowered the psi I dont think they are rated the same speed..

I say this becuase my GY marathons I had were 65 mph rated. But GY stated if you run 10 psi more they rate them to 75 mph...

This is such BS..

Kenda.

http://specialty.kendatire.com/en-us/find-a-tire/trailer/karrier/

GY added inflation bulletin.And ironically the added psi does not add additional load capacity...

https://www.tirerack.com/images/tires/goodyear/Marathon_Special_Trailer_Applications.pdf

also says this for the valve stem gurus...

Tubeless snap-in type valves, depending on the type valve, are rated for a
maximum inflation pressure of 65 or 80 psi for nominal 0.453” diameter valve
holes. If a higher cold inflation pressure is used, a clamp-in valve such as TR416S
valve (200 psi maximum inflation) must be installed

[time2roll]

lawrosa wrote:
https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

What other tires are recommended here? I read something on maxis tires?

I think something has changed at Maxxis. For many years they were bullet proof, the real go to quality tire. So I bought some about five years ago and just short of four years the tread cap was coming off. Lucky to spot it just before a trip. For the last couple years the reports of Maxxis issues have been trickling in. Still a good tire but I had to move on and went with Endurance rated 87 mph. Carlisle HD seems to get good reports with the new improved tire but previously they had many reports of failure. That is my perception and summary of anecdotal evidence.

Also the Kumho 857 has received good reviews and is well recommended for 14". I believe it is a an LT style tire but comes at a bit higher price. Shop around.

[lawrosa]

But with the 14s, first you need that spec info on the wheels which you can't get unless you take the tire off--so do that with the spare to make life easier.

Im pretty sure all wheels of this flavor are 1870lb rated. Looking at most all 14" in task master, and carlisle show this spec. Although I cant find the definite wheel coachman uses online.

I know the rims are made by hispec as there is a sticker on all the rims. But their site shows all aluminum. These are steel rims..

http://www.hispecwheel.com/categories-list/142/Specialty-Trailer-Wheels

[time2roll]

lawrosa wrote:
And ok I assume we are talking a 100 psi valve stem replace.. With brass end..

Yes I recommend those as you should be able to get them for free over the standard 50 psi stems that are weak.

Of course you can pay extra for metal too but is overkill IMO.

[BFL13]

It boils down to confirming or not that you can use the PSI vs weight for STs same a with LTs. (which I was saying I doubt, but can't confirm)

I ended up getting the newer kind of Carlisles for the 5er, never mind the bad rep of the previous line of Carlisles.

[lawrosa]

BFL13 wrote:
You want to run your Ds at 50lbs the same as the Cs is the issue. My understanding is that you can do that with LT Ds but not with ST Ds.

I may have this wrong, but from reading various tire posts, STs should be fully inflated, but you can do the weight/PSI table thing ok with LTs.

EG I have LT Es on my wheels that came with Ds but limit the LT Es to 65, even though they can go to 80, but the wheels might only do 65 as for Ds (have not checked the actual wheel specs in case they can do more than 65. Don't need more than 65)

Thanks for that.. Hmmm

The inflation tables are for st tires.

So @ 50 psi they are 1760 just like my C's.

x 4 thats 7040. If I loaded the trailer to max 7000 lbs. ( Will never happen I can tell you but if I did whats the impications of running 50 psi?

Alright alright, somehow in my head I feel I will do something drastic if I dont inflate to 65 psi is why I asked the question..

To meet someway towards a middle point I stated I would be willing to do 55 psi.


I have to admit when I did my trip to florida and back my 81 mph jaxxons saw 75 mph most of the trip down rt 95 b lining it there. I checked pressures every morning before heading out. Maintained 50 psi diligently.


https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

What other tires are recommended here? I read something on maxis tires?

[BFL13]

You want to run your Ds at 50lbs the same as the Cs is the issue. My understanding is that you can do that with LT Ds but not with ST Ds.

I may have this wrong, but from reading various tire posts, STs should be fully inflated, but you can do the weight/PSI table thing ok with LTs.

EG I have LT Es on my wheels that came with Ds but limit the LT Es to 65, even though they can go to 80, but the wheels might only do 65 as for Ds (have not checked the actual wheel specs in case they can do more than 65. Don't need more than 65)