Travel trailer newbie!

[KATOOM]

I guess a few of us will just have to agree to disagree.....  Thats OK too as thats what makes the world go around.

 

From all I've ever learned and understood and lived by, running ST tires at max sidewall pressure is NOT considered over-inflation.  I've followed this practice for years and I've never experienced any odd or irregular tread wear patterns, and it didn't matter what tire trailer either.

 

And in saying that, ST tires are made to "time out" before the tread wears out.  5 years and they're supposed to be replaced.  How many people do you know who follow this rule?  I personally know of none and have only read where one forum member does.

 

As for tire companies "wanting" their ST tires run at varied pressures dependent on load.....  I cant confirm or deny this.  Yes, there are charts out there but show me where this actual "wanting" language is used by the tire manufacture.  Thats not me stating anyone here is wrong but just wanting the proof behind the pudding.  By the way, I emailed two tires companies about this air pressure question in ST tires not long ago too.  Of those I got one totally vague response from one and no response from the other.  Maybe they dont want the liability risk.

 

And yes, trailers will most certainly lock up the tires more easily based on pressure and load.....but thats why brake controllers are adjustable too.

 

As for class 8 tires, I've never understood the problem to be from sidewall belts.  But rather I understood the problem is sidewall "zipper" failures from over fatigued belts.  The reasons for this failure is predominantly caused by under inflation, running duals flat, and running over abrupt surfaces like curbs.  They plys pull apart which causes bulges and air gaps.  These damaged tires are supposed to fail retread inspections but often dont.

 

Nonetheless, I adjust my vehicle tires per their load but again, ST tires are not designed to "flex".  So to each is own.....

Edited July 12, 2016 by KATOOM

[AH64ID]

Running max sidewall pressure isn't over-inflated as long as you're at max load. Any load less and it is over-inflated. That too is a broad generalization but the only tire company (not 3rd party, but actual tire manufacturer) that I have ever seen that wants their trailers at max psi is the one you linked the other day.. Carlise? Otherwise every single tire manufacturer I have researched wants proper pressure for the load, and anything else is under-inflated or over-inflated. 

 

Too much air for the load absolutely is over-inflated. 

 

Everybody I know with a car trailer or a dump trailer has crappy tire wear on their trailers from running max psi all the time. The centers wear out very fast at max pressure and min load. 

 

Where did you find that ST tires are not supposed to flex? First I have ever heard of it. In fact they need to have plenty of sidewall flex in order to scrub on tandem and triple axle setups. 

 

When I was talking to Toyo about how low I could run my 19.5's I understood the 70 psi minimum to be twofold. First is keeping the bead set as xx.5" tires don't hold beads like car rims, and second was to prevent flexing and heat buildup in the sidewall. These tires are not supposed to flex. 

 

I have also worn ST's out quite easily inside their 5 year window, and honestly not even with that many miles on them. Traveling on gravel/dirt/chipseal roads is hard on tires. 

[KATOOM]

Well again.....I think this is a "to each is own" kinda topic.  I'm not saying I'm right but I'm certainly not calling anyone foolish either for advising anything other than maximum air pressure in their ST tires, or running whatever air pressure they choose.  Its their stuff and their money.....

 

But that said, if running the maximum rated air pressure is truly over-inflated in an ST tire then someone better call Carlise because they're misinforming their customers.  Same goes for multiple tire distributors selling ST tires who say the same thing.  As for what any other tire manufacture "wants".....  As I mentioned, I tried to pin a couple of them down to what they deem necessary for their ST tires but you read what I got.  Does that mean Carlise stands alone?  I cant say.....

 

Point being is we all have an opinion on this topic with seemingly no proof on either side but lots of experience shared doing it both ways.  So we could battle back and forth and bore everyone which certainly isnt productive either.  And Actually, all I care about is that no member has a any problems on the road and is safe.  I think we can both agree on that.

 

[Mopar1973Man]

Something to consider KATOOM...

 

Let's say I upgraded to Load Range G's (14 ply) on the RV. 3,750 pounds @ 110 PSI that is a gross capacity of 15,000 pounds for a mere 8,500 trailer GVWR. The OEM tire is a mere load range D (8 ply). Would you still inflate to max sidewall pressure? Reason why I point this out I've seen people do this upgrade on RV and other trailers where they are well above the GVWR rating of the trailer and still using max inflation pressure it is way over inflated. So in my using my RV as an example here it would be grossly over inflated.

 

One of the gents I do work for I advised him as well. He told me he upgraded axles so he could run the Load Range G's on his enclosed trailers which came original with load range D's. The load range G's have a heavier carcase and can take a bit more abuse still in all with a 110 PSI max inflation there is no need to be that high. So be aware using the blanket statement of using max inflation does not cover every possible combination of trailer, axles, tires, and loads. Not everyone kept the factory size, load range or capacity tires which typically require a max inflation to hold GVWR.

 

Again in the OP case of rental RV's you never know what the OEM tire was nor if they upgraded to load range well above. You never know...

[notlimah]

Great points on tire pressure fellas.

 

Just so you all know, the rental agreement for me only requires that I keep tire pressure at 'the proper psi' so unless one of them tell me to keep tire pressure at this, then I'm going to be left up to doing it myself. I do pickup the trailer the night before I leave so I'll post back here with the kind of tires and all that jazz and see what you guys think.

[KATOOM]

16 minutes ago, Mopar1973Man said:

Something to consider KATOOM...

 

Let's say I upgraded to Load Range G's (14 ply) on the RV. 3,750 pounds @ 110 PSI that is a gross capacity of 15,000 pounds for a mere 8,500 trailer GVWR. The OEM tire is a mere load range D (8 ply). Would you still inflate to max sidewall pressure? Reason why I point this out I've seen people do this upgrade on RV and other trailers where they are well above the GVWR rating of the trailer and still using max inflation pressure it is way over inflated. So in my using my RV as an example here it would be grossly over inflated.

 

If the trailer is "rated" at 8500 lbs then the likelihood is thats a completely dry bare boned assessment by the trailer manufacture and its going to weigh more around 9000 lbs.  Then another 1000-1500 lbs of food and clothes and camp stuff, depending on how comfortable the camper likes.  Then another 500 - 700 or so lbs for water and propane.  So that 8500 lb trailer rolls away at more like 10k -11k lbs.....  Yes, I'd take that added 4k-5k of tire capacity and run with it in confidence.

 

My triple axle 5th wheel came with six D's.  Its manufacture rated at 12,500 but I know better as I've scaled it.  The pin is around 3000 lb so there's technically 11k or so on the axles, depending on what I have loaded.  Six of those D's hold 15k so they should be fine.  But I chose E's and increased my tire capacity to about 17k.....around 14k on the axles.  I run them at maximum pressure and I couldn't be happier.  These tire are wearing like iron and they run cool on the highway.  I just cant see why this is a problem.....

[Mopar1973Man]

No. You are backwards.

 

Dry weight is 6,588

GVWR is 8500

 

Actual weights are with full water, empty waste tanks, food and clothing.

 

Again if I upgrade to load range G's at 3,750 @ 110 PSI would you still max inflate? Again max inflation doesn't always fit the trailer, tires, or loads. As you can see my actually scaled weight and GVWR. Still in the future I might upgrade to G's I never know if there is a good sale on them.

Edited July 13, 2016 by Mopar1973Man

[TFaoro]

2 hours ago, notlimah said:

Great points on tire pressure fellas.

 

Just so you all know, the rental agreement for me only requires that I keep tire pressure at 'the proper psi' so unless one of them tell me to keep tire pressure at this, then I'm going to be left up to doing it myself. I do pickup the trailer the night before I leave so I'll post back here with the kind of tires and all that jazz and see what you guys think.

 

Do it the easy way to protect your own butt.... talk to the service manager. Have him write down what pressure HE wants the tires at, and have him sign it if you can. This way it takes the liability off of you and puts it on the service manager.

[notlimah]

It's a small start up company, but I was planning on asking them what they wanted just to avoid any blame being shifted to me!

[oldbeek]

In 80,000 miles of towing, i always run the pressure indicated on the side of the tire. Lower pressures will allow flexing on sharp and jack knife backing that will cause tread seperation and blow outs. With proper suspension and alignment the tires wear perfectly at max psi

[KATOOM]

2 hours ago, notlimah said:

It's a small start up company, but I was planning on asking them what they wanted just to avoid any blame being shifted to me!

 

Thats a great idea.  I'm sure they'll probably offer you some kind of "extra" insurance for such problems too, but check to see what your insurance company will cover as well.  You just dont want to be responsible for any unforeseen problems.

[AH64ID]

On ‎7‎/‎13‎/‎2016 at 11:13 AM, KATOOM said:

 

If the trailer is "rated" at 8500 lbs then the likelihood is thats a completely dry bare boned assessment by the trailer manufacture and its going to weigh more around 9000 lbs.  Then another 1000-1500 lbs of food and clothes and camp stuff, depending on how comfortable the camper likes.  Then another 500 - 700 or so lbs for water and propane.  So that 8500 lb trailer rolls away at more like 10k -11k lbs.....  Yes, I'd take that added 4k-5k of tire capacity and run with it in confidence.

 

My triple axle 5th wheel came with six D's.  Its manufacture rated at 12,500 but I know better as I've scaled it.  The pin is around 3000 lb so there's technically 11k or so on the axles, depending on what I have loaded.  Six of those D's hold 15k so they should be fine.  But I chose E's and increased my tire capacity to about 17k.....around 14k on the axles.  I run them at maximum pressure and I couldn't be happier.  These tire are wearing like iron and they run cool on the highway.  I just cant see why this is a problem.....

 

 

Say what??

 

Rated is rated not dry weight.

 

If a trailer is rated for 8,500 that means just that... it's rated for 8,500lbs That includes food, toys, etc. Not sure why you think a 8,500lb rated trailer would be 11K lbs!!

 

Trailer GVWR include the tongue weight. A 12,500 rated 5er should have about 3,125 max pin weight and 9,375 on the axles, per the rating.

 

There is far more to a trailer GVWR than the tires. You're doing some very fuzzy trailer math.

[KATOOM]

By saying "rated" I was merely meaning the factory claimed weights and then the rated numbers in relation to that false figure they throw out there.  Simply trying to point out that everything is a heck of a lot heavier than we generally think.

Sorry for the confusion.  Excessive life stresses and over working has seemingly inflicted some vertical comma induced posts.

[Mopar1973Man]

1 hour ago, KATOOM said:

Simply trying to point out that everything is a heck of a lot heavier than we generally think.

 

That why there scales all around. I don't over load my trailers typically. Also there is a reason GVWR is stamped or labeled on all vehicles.

 

Since I was just down at Tire Factory Ontario, OR yesterday I ask the tire tech there about the pressures you should run in your ST tires. His response is that you should not be running MAX inflation pressure unless the trailer is meeting the load limitations of the tire. ST tire should not be inflated solid or max inflation to the point of no flex at all this will cause tire damage. He agrees that if the tire is marginal and barely covers the trailer weight then yes you'll be forced to max inflate the tire. Even he suggests it's bests to be a load range higher and not have to max inflate ST tires. All radial tires are intended to flex hence why the design of the tire.

Edited July 15, 2016 by Mopar1973Man

[KATOOM]

26 minutes ago, Mopar1973Man said:

 

That why there scales all around. I don't over load my trailers typically. Also there is a reason GVWR is stamped or labeled on all vehicles.

 

Because of insurance liabilities.....

[dripley]

Just to stir the pot on tire ratings. I had to buy my last set under duress. Lost one with 2 more on the way out on a Sunday drive back home from Iowa I believe. I ended up with a set a Carlisle Dura Trac. It was the quickest I could get my hands on at the time. I asked about the load rating and all seemed fine. Upon further inspection they turned out to be load range F tires and not G's. But the load rating on them are 3960# at 90 psi. As I remember my G's were all rated around 3750# at 110 psi or there abouts. Not sure what to think of that but they have held up better than anything I have run on this trailer.

[Mopar1973Man]

7 minutes ago, dripley said:

But the load rating on them are 3960# at 90 psi.

 

Good Gawd... Those can carry serious weight. Could you throw a link of the tires you are running. I might want to buy some next time. On a dual axle trailer that's 15,840 pounds of carry capacity! 

 

8 minutes ago, dripley said:

Lost one with 2 more on the way out on a Sunday drive back home from Iowa I believe.

 

I've got to ask what speeds are you still running? I know you run a lot of interstates.

[dripley]

14 minutes ago, Mopar1973Man said:

 

Good Gawd... Those can carry serious weight. Could you throw a link of the tires you are running. I might want to buy some next time. On a dual axle trailer that's 15,840 pounds of carry capacity! 

 

 

I've got to ask what speeds are you still running? I know you run a lot of interstates.

Here is the link for the tire http://www.carlstargroup.com/product/tires/trailers-toy-haulers-towables/radial-trail-rh. I was a little off on the tire pressure. 95 instead of 90. And there is a note that says the PSI shown is the recommended PSI. I have run these at a lower psi based on 12k to 12.5k on the axles, around 85 psi. 

 

On that trip I was running 65 to 70 mph on the interstate.I was trying to stay around 2k rpm but since have found the truck pulls just as good at 1850 as it does at 2k. Thanks for slowing me down because I used tow 70 to 75. My old tires had about 3 to 3.5 years on them and that is the best I seem to be able to get out of a set of tires, ST or LT. So far I have 3.5 years on these and they still seem fine, but so did all my others. My next trip will tell.

[TFaoro]

Those tires are beasts! 

 

We are currently looking at swapping the 16.5s on the gooseneck out for 16s and need some strong tires. Thanks for the link! 

[AH64ID]

 

7 hours ago, KATOOM said:

By saying "rated" I was merely meaning the factory claimed weights and then the rated numbers in relation to that false figure they throw out there.  Simply trying to point out that everything is a heck of a lot heavier than we generally think.

Sorry for the confusion.  Excessive life stresses and over working has seemingly inflicted some vertical comma induced posts.

 

Gotcha. Delivery/Curb/Brochure weight :-) 

 

6 hours ago, KATOOM said:

 

Because of insurance liabilities.....

 

It really depends. In most cases it's the operational limit of some component. The frame, axles, tires, brakes, etc. There are also rare "marketing" instances, just like between a 2500 and SRW 3500. Those are much more rare on a trailer thou. 

 

Just increasing tires doesn't mean you can carry more. 

 

 

And yes many things these days are just for liability...I just try not to pin everything on that.

Edited July 16, 2016 by AH64ID