Tire Pressure

[LCrabtree]

Originally Posted by Javi

Just a note... if the tires were filled to 80 psi at say 90 degrees and the current air temp is say 75 it is not unusual to see a drop of 10 psi..

I pay special attention when I'm travelling distances where the weather changes noticeably. Last fall we travelled from Central Texas to Washington state. For the first few nights and mornings I was very concientious about checking the tire pressures on both the trailer and the pickup. Going north into cooler climates, I had to adjust the tire pressure every few mornings.

[wegone]

Originally Posted by sourdough

What tire size and load range do you have? 225/75r15? If LRD it IS 65psi.

Edit: If you would go to the user CP in the upper left hand corner of the page and fill in your signature with trailer and TV info it helps get accurate answers and prevents a zillion needless questions as mine above.

I have ST205/75R15D which means....WHAT?

The sticker on the trailer and the markings on the tire are the same.
Can I go with a better tire?
These were what came with it, Trailer Kings, or something like that.
I have a long trip planned this fall from Washington to Southern California and back, I don't care to chance anything if I can avoid it beforehand.
Tires are two years old, look good by my inspections, minimal inside edge owear on both rear axle tires.

Thank you.

[sourdough]

Originally Posted by Island Eddie

I have ST205/75R15D which means....WHAT?

The sticker on the trailer and the markings on the tire are the same.
Can I go with a better tire?
These were what came with it, Trailer Kings, or something like that.
I have a long trip planned this fall from Washington to Southern California and back, I don't care to chance anything if I can avoid it beforehand.
Tires are two years old, look good by my inspections, minimal inside edge owear on both rear axle tires.

Thank you.

The ST205/75R 15 is the tire size on the wheel and the one dictated for your trailer per the sticker. The D is the load range - 2150 lbs. at 65psi for that size tire. It appears that the D is the highest load range for that size.

Yes, you can go with a better tire. If they are Trailer Kings you are living on borrowed time (or past) at 2 years. Carlisle makes the Radial Trail HD in that size and so does Goodyear in the Endurance. I've used the Carlisle tires and had very good luck with them. Either would be a huge step up in quality over the TK tires. Discount tire has them both and the Carlisle is considerably cheaper $87 vs $130 for the Endurance.

[TopoTony]

The sticker says GAWR (Each Axle) 5200 lbs

[wegone]

Originally Posted by sourdough

The ST205/75R 15 is the tire size on the wheel and the one dictated for your trailer per the sticker. The D is the load range - 2150 lbs. at 65psi for that size tire. It appears that the D is the highest load range for that size.

Yes, you can go with a better tire. If they are Trailer Kings you are living on borrowed time (or past) at 2 years. Carlisle makes the Radial Trail HD in that size and so does Goodyear in the Endurance. I've used the Carlisle tires and had very good luck with them. Either would be a huge step up in quality over the TK tires. Discount tire has them both and the Carlisle is considerably cheaper $87 vs $130 for the Endurance.

PERFECT....thank you Sir. I will go with the Goodyear.

Question...you say 2150 lbs is that "per tire" thus 4 tires can carry 8300 lbs together?

[TopoTony]

Did the pressure decrease when going from TX to WA?

[Tireman9]

Originally Posted by TopoTony

I just picked up a pre-owned '21 Hideout 174RK. The tires say max 80psi, the sticker on the unit says 80psi. The current pressure is 70. I thought there should be a recommended, but all I see is the max stated on the tires and on the side sticker. Thanks for any advise on this. Sorry if this has been discussed...couldn't seem to find my specific details.
https://www.keystoneforums.com/forum...1&d=1632244101


https://www.keystoneforums.com/forum...1&d=1632244101

The Certification sticker has the MINIMUM cold inflation needed to support the stated weight GAWR. You can not look at your tires or the "stuff in the RV and know the actual weight. As a MINIMUM you need to load the RV with all the "stuff" you might carry i.e. fully loaded. Then get on a truck scale available at many truck stops along the interstate or at a local building supply or sand & gravel pit. You then consult the tire Load & inflation tables that I think are in your owner's manual or available on line and learn the MINIMUM PSI required to support rour actual measured load.


Note the tire load capacity should be AT LEAST 110% of the measured load on each axle. I have sent you PM with more info.

[sourdough]

Originally Posted by Island Eddie

PERFECT....thank you Sir. I will go with the Goodyear.

Question...you say 2150 lbs is that "per tire" thus 4 tires can carry 8300 lbs together?

Yes, it's per tire; 2150 x 4 = 8600lbs. vs a trailer gvw of 7600 lbs.

[jadatis]

Originally Posted by TopoTony

GVWR 5200
Each axle 5200

I put in 78psi. Checking them now, after traveling, they are both down 5 lbs. However, we descended from 2800’ elevation to sea level. Wonder if that is the cause of the psi loss?

My much bigger problem is that the trailer brakes aren’t working. I have checked So many things troubleshooting… adjusted brakes, traced current, etc. The Curt controller does not have any problems showing. I can hear the brakes buzzing when applying the manual controller switch. Have not actually tested again while moving. Jacked up the trailer and spun the wheel, but I think you have to be going about 20mph for a test.

If your GVWR is realy only 5200lbs, my spreadsheet comes to 42 psi with all the maximum reserves , but no screws trembling loose.

But I daubt that, because both axles 5200lbs , so even one can carry the complete TT, not even substracting the pinweight.
Your payload is 1100 lbs .

If I assume 5200 GAWRS and simply calculate for that it comes to 98 psi., and then recomended 80 psi would be expected.

So look again, or GAWR's are wrong, or GVWR.

[LHaven]

Originally Posted by TopoTony

Is there a recommended portable compressor? My Bostitch is way to big and heavy to tote with us. Anyone use this Ryobi, listed on Amazon?
Ryobi 18-Volt ONE+ Cordless 1 Gal. Portable Air Compressor

Anything by Viair is often considered the gold standard. We use this Kobalt, which was given to us by a friend for Christmas, and have been quite happy with it, as it works off both AC and DC, and has both a valve clamp and a target pressure shutoff, so I don't have to babysit it while it's doing its job.

[Tireman9]

Originally Posted by sourdough

Yes, it's per tire; 2150 x 4 = 8600lbs. vs a trailer gvw of 7600 lbs.

OK you have some of the information needed.
GVWR is the highest the trailer should ever weigh but not a statement on what it actually does weigh.



And it is possible to exceed that but not know it unless you get on a scale.


It is also possible to overload one axle and still be under the GVWR


Tires only react to the load on them not to the load on the other tires.



Also Tire load capacity (from load tables) should be 110% of the GAWR fro each axle per RVIA standards (Sticker by the entry door of the RV.

[sourdough]

Originally Posted by Tireman9

OK you have some of the information needed.
GVWR is the highest the trailer should ever weigh but not a statement on what it actually does weigh.



And it is possible to exceed that but not know it unless you get on a scale.


It is also possible to overload one axle and still be under the GVWR


Tires only react to the load on them not to the load on the other tires.



Also Tire load capacity (from load tables) should be 110% of the GAWR fro each axle per RVIA standards (Sticker by the entry door of the RV.

Read my post; I gave max weight per tire, total max weight for 4 tires and gvw of trailer, after that you are just making "statements". Without a scale weight of anything you're simply muddying the water about what I said/he asked.

The poster asked a simple question about the max weight supported by the tire and if it was x 4.....I responded. Your further explanations are correct but have no relevance to the question he asked or the answer I gave.

[wegone]

Originally Posted by sourdough

Read my post; I gave max weight per tire, total max weight for 4 tires and gvw of trailer, after that you are just making "statements". Without a scale weight of anything you're simply muddying the water about what I said/he asked.

The poster asked a simple question about the max weight supported by the tire and if it was x 4.....I responded. Your further explanations are correct but have no relevance to the question he asked or the answer I gave.

It's all good...I am trying to gain as much info as I can respectfully so I can relax and enjoy my retirement and pulling more.
It doesn't take much imagination to understand that two of the most critical components with towing is the hitch and the tires, leaving the vehicle out of the equation for the moment.

The cost of tires from low end to high end product is nothing when compared to the possibility of the cost of a failed tire while in route.

I do factor that in, like insurance, I'll opt for better coverage than the just barely, with the difference being a couple of brews per month at a local pub on vacation....not so sure if a penny wise lends itself to dollars saved, when it comes to items that bring a element of safety along with them....

It's how I roll....

EDIT: I just finished up installing the TST-507 monitoring system on the rig. It was actually pretty easy, and I am not that techno savvy. Pretty cool reading pressure and temp constantly as it scrolls through all the tire positions. I believe a wise investment for sure.....thanks to what I read/learned on the site here.

[CWtheMan]

Originally Posted by TopoTony

GVWR 5200
Each axle 5200

I put in 78psi. Checking them now, after traveling, they are both down 5 lbs. However, we descended from 2800’ elevation to sea level. Wonder if that is the cause of the psi loss?

My much bigger problem is that the trailer brakes aren’t working. I have checked So many things troubleshooting… adjusted brakes, traced current, etc. The Curt controller does not have any problems showing. I can hear the brakes buzzing when applying the manual controller switch. Have not actually tested again while moving. Jacked up the trailer and spun the wheel, but I think you have to be going about 20mph for a test.

The vehicle recommended inflation pressures for your LRE tires is 80 PSI. Why would you use less?

[LHaven]

Originally Posted by CWtheMan

The vehicle recommended inflation pressures for your LRE tires is 80 PSI. Why would you use less?

I just assumed his portable pump wasn't up to it.

I had the same brake problems. Multiple visits to the Ford dealer, and his tire/trailer/paint shop subsidiary. Finally took it to a pro RV shop and they showed me that not only were the brakes full of grease, but the Ford tire shop actually doubled down on the problem.

[sourdough]

Originally Posted by Island Eddie

It's all good...I am trying to gain as much info as I can respectfully so I can relax and enjoy my retirement and pulling more.
It doesn't take much imagination to understand that two of the most critical components with towing is the hitch and the tires, leaving the vehicle out of the equation for the moment.

The cost of tires from low end to high end product is nothing when compared to the possibility of the cost of a failed tire while in route.

I do factor that in, like insurance, I'll opt for better coverage than the just barely, with the difference being a couple of brews per month at a local pub on vacation....not so sure if a penny wise lends itself to dollars saved, when it comes to items that bring a element of safety along with them....

It's how I roll....

EDIT: I just finished up installing the TST-507 monitoring system on the rig. It was actually pretty easy, and I am not that techno savvy. Pretty cool reading pressure and temp constantly as it scrolls through all the tire positions. I believe a wise investment for sure.....thanks to what I read/learned on the site here.

Eddie your thoughts and conversation are on the right track. My previous post was when Tireman tried to interject information you weren't looking for.

You did well with tire choice AND the TPMS, I run a TST 507 myself, been happy and have had no issues. Just ask questions about anything at anytime, we are here and have either the answer OR some thoughts on it.

[wegone]

Originally Posted by sourdough

Eddie your thoughts and conversation are on the right track. My previous post was when Tireman tried to interject information you weren't looking for.

You did well with tire choice AND the TPMS, I run a TST 507 myself, been happy and have had no issues. Just ask questions about anything at anytime, we are here and have either the answer OR some thoughts on it.

Oh I love being a pest....

Seeing I only have 5-7k mileage on my tires and just barely 2 years since I purchased my trailer ( I have not looked at the manufactured date on them ) and knowing how they build as cheap as they can, to offer the BEST DEALS....while still maximizing profit ( ya gotta love capitalism )

Tires are a great place to utilize that margin, lean on the vendor for better pricing, you get a cheaper product that just covers barely the need...the unknown is, for HOW LONG?

With 3000 mile trip fast approaching, its a no brainer...even for this Tinman

I think I will still stay with the 205 instead of the 225 because I have the spread axles....I'm thinking a wider tire will only put more stress under the trailer on the winding roads, with that flexing, and I have my payload covered as is...

Thanks for your help.

[notanlines]

Originally Posted by LCrabtree

I pay special attention when I'm travelling distances where the weather changes noticeably. Last fall we travelled from Central Texas to Washington state. For the first few nights and mornings I was very concientious about checking the tire pressures on both the trailer and the pickup. Going north into cooler climates, I had to adjust the tire pressure every few mornings.

Changing those pressures ever few mornings because of temperature changes is not a practice bolstered by the tire industry.

[TopoTony]

Hey LHaven, you were right on. Not only were they full of grease, but both shoes on both sides completely gone. Metal on metal. I can only assume the previous owner had a malfunction with his controller and it caused the brakes to engage. Then maybe the heat blew the seals.

[CWtheMan]

Let's go right to the bottom line. You say your trailers certified GAWRs are 5200#. When we add in the RVIA 10% load capacity reserves the very minimum tire load capacity per axle end for your axles is 2860#. The ST225/75R15 LRE provides - guess what? - 2860# of load capacity at 80 PSI.

If unhappy with that 10% in load capacity reserves the ST225/75R15 is also built with a LRF & LRG load capacity rating. Load Range is not part of a tire's designated size so adding a load range will give you the option to increase the PSI to get the desired load capacity reserves. The wheels and valve stems must have the capability to support the higher PSI rating.