OEM Rims Air Pressure

[canesfan]

I know it's on here, but I can't find it. Search throws out the words "rim" and "air" which leaves me with "pressure" and that doesn't work.

How do I tell how much air pressure my OEM rims are capable off? Is it stamped somewhere and if so is it in english or is it coded?

Considering going form E to F tires and want to see if I need new rims to do that.

Thanks!

[Quad]

My Laredo came with Sendel wheels. On the back side in the spoke area it was stamped with a weight and psi rating. I then did a google search for Sendel wheels and also found my rim on their products page and confirmed my findings. Hope that helps.


2005 Silverado 2500HD D/A
2013 Laredo 321BH

[Ron]

Our Montana also has the psi rating on the back of a spoke...

[fla-gypsy]

I have found a weight rating on my OE wheels but never a PSI rating

[canesfan]

Thanks, I have Sendel wheels, it's stamped on the outside , but haven't been able to locate anything else on the rim. When it gets warmer/drier I'll crawl all the way under and see what I can see, but the brake drum block most of the inside of the wheel.

Thanks for the help!

[CWtheMan]

RV trailer rim information is not easy to explain because most people have a perception that may only be partially true.

Determining rim specifications is the responsibility of the Society of Automotive Engineers (SAE).

The DOT directs tire manufacturers to provide a list of rims suitable for fitment to every tire they manufacturer and make that list available to the public. That basic description is something like; 16x6.5 etc.. It will be displayed on your trailer’s federal certification label along with the tire size fitted to it.

Rim load capacities and pressure ratings are not required to be displayed on individual rims. Because vehicle manufacturers may have more than one vehicle design for acceptable use of like sized rims the rim manufacturer will add load capacity, pressure capacity or both on those rims.

The DOT does require rim manufacturers to identify the rims they build. The rim builder must put their name, rim model/part number, and serial number on all rims they manufacturer. So, bottom line, when in doubt, contact the rim builder.

p.s. When ordering replacement rims make sure the seller understands that you want RV trailer rims at zero offset.

CW

[Quad]

If you go to Sendel's web page and locate your model and look for you lug pattern and rim size you'll find the ratings your looking for, their website has a lot of specs on it for their products. If by some chance you can't find it on their page email them and they'll reply back fairly promptly.


2005 Silverado 2500HD D/A
2013 Laredo 321BH

[canesfan]

Thanks for all the info. I did look at the Sendel website and found my rims.

3750 @ 110 PSI
** 3750 LBS @ 110 PSI & CERTIFIED SAE J1204 SPECS

So I can go to F tires if I choose to, however I still only have 7000# axles. The E tires on mine now are 3520# tires and I'll be replacing them soon with something better, even if only another E tire.

Was wondering if the F tires with more air pressure and plies ride harder than E tires? Never really thought about it before. Not sure how this Raptor rides, only towed it home. My last 5er rode like junk, everything was always thrown around, cabinets and drawers open whenever I got to where I was going. Granted our roads are getting worse and worse, but I never had a rig that rode as bad as that one did.

[JRTJH]

It's been my experience that a heavier trailer will ride OK with heavier sidewall tires. It's the lightweight 3500 lb flatbed type trailer with LR F tires that tends to bounce and not ride smooth. They ride more like the tires are made of solid hard rubber. Heavier trailers have enough weight to cause the sidewalls to flex and absorb some (or most) of the road vibrations.

Another consideration if you're into modifications to make things better, is to add shock absorbers to your trailer axles. I'm seriously considering this for my rear kitchen fifth wheel. We had shocks on our Holiday Rambler and never had anything out of place. Monroe makes an adapter kit/shock setup for "not too much money" If you do decide to go to LR F tires and find that things get shaken up too much when towing, adding shocks is one option that will probably improve your ride of what you've got now.

[canesfan]

Thanks, that all makes sense and adding shocks is definitely an option if I see there's a need. My initial thoughts are to go with F tires and and if they ride too rough at 95 psi play with air pressure a little first. Now I do understand heat and such on an underinflated tire. I used to have a chart put out by Michelin that listed various air pressures for their tires and the corresponding weight ratings at each air pressure. I used this when I had a 5er that came from the factory with Michelin LT tires. According to that chart I could run between 72 - 76 PSI on an E tire and be good with weight capacity for that trailers weight. I would run 75-76 psi, I monitor my tires very well and I never had them run hot nor had a problem in the 5 years I had that trailer. The tires looked new the day I traded it in.

I know there are people who swear you must inflate a tire to its max cold rating, no matter what, and there are others who swear this is untrue, including some tire people I have talked with, and Michelin. Not trying to start a tire pressure war, just thinking out loud about options.

[ocho]

Originally Posted by canesfan

Thanks, that all makes sense and adding shocks is definitely an option if I see there's a need. My initial thoughts are to go with F tires and and if they ride too rough at 95 psi play with air pressure a little first. Now I do understand heat and such on an underinflated tire. I used to have a chart put out by Michelin that listed various air pressures for their tires and the corresponding weight ratings at each air pressure. I used this when I had a 5er that came from the factory with Michelin LT tires. According to that chart I could run between 72 - 76 PSI on an E tire and be good with weight capacity for that trailers weight. I would run 75-76 psi, I monitor my tires very well and I never had them run hot nor had a problem in the 5 years I had that trailer. The tires looked new the day I traded it in.

I know there are people who swear you must inflate a tire to its max cold rating, no matter what, and there are others who swear this is untrue, including some tire people I have talked with, and Michelin. Not trying to start a tire pressure war, just thinking out loud about options.

There is really good debate on the thread I started. If I were in your position, I would go with the Carlisle Radial Trail RH "F" load rated tire. Or even better a "G" rated tire. Then you have a bullet proof option. It would be my thoughts to run a tire at its full air pressure regardless of the load. That would be 110psi. for the "G" tire.

[Quad]

I would run full air pressure unless there is a reason not too. But if there is a reason not to, then I wouldn't worry as long as you maintain a safe capacity for the weight of the trailer. There are load inflation charts for that reason.


2005 Silverado 2500HD D/A
2013 Laredo 321BH

[CWtheMan]

Originally Posted by Quad

I would run full air pressure unless there is a reason not too. But if there is a reason not to, then I wouldn't worry as long as you maintain a safe capacity for the weight of the trailer. There are load inflation charts for that reason.


2005 Silverado 2500HD D/A
2013 Laredo 321BH

Tire pressure reference.

http://www.safercar.gov/Vehicle+Shop...d+Load+Limits#

CW

[Festus2]

CW -

In the above link to safercar.gov, it states that you should inflate your tires to the pressure stated on the placard placed there by the manufacturer - not the cold pressure stamped on the tire. This "number" is good only for the OEM tires - is it not? If Keystone placed the placard there for D Load range tires at say 60psi, and you decided to put E range tires that have 80 psi stamped on the tire, then the placard would not be applicable for the new set of tires.

[bobbecky]

It really depends on the wheels. On my rig, the wheels are rated 110 psi and 3750 lbs capacity, so I inflate my G range tires to 110 psi. If my wheels were rated less, I may not have installed G range tires, but would only be able to inflate to the maximum pressure rating of the wheels, or install higher rated wheels. The tires on these trailers should be inflated to the highest pressure, whether it is the tire max cold or the max allowed on the wheel, due to the stresses from towing and maneuvering that causes side stress on the tires. The tires don't provide much cushion to the ride, that is the job of the suspension system. The highest pressure will give lower temperatures to the tires and that will make the tires last longer and be less likely to fail due to heat.

[Quad]

Originally Posted by bobbecky

It really depends on the wheels. On my rig, the wheels are rated 110 psi and 3750 lbs capacity, so I inflate my G range tires to 110 psi. If my wheels were rated less, I may not have installed G range tires, but would only be able to inflate to the maximum pressure rating of the wheels, or install higher rated wheels. The tires on these trailers should be inflated to the highest pressure, whether it is the tire max cold or the max allowed on the wheel, due to the stresses from towing and maneuvering that causes side stress on the tires. The tires don't provide much cushion to the ride, that is the job of the suspension system. The highest pressure will give lower temperatures to the tires and that will make the tires last longer and be less likely to fail due to heat.

Well said



2005 Silverado 2500HD D/A
2013 Laredo 321BH

[CWtheMan]

Originally Posted by Festus2

CW -

In the above link to safercar.gov, it states that you should inflate your tires to the pressure stated on the placard placed there by the manufacturer - not the cold pressure stamped on the tire. This "number" is good only for the OEM tires - is it not? If Keystone placed the placard there for D Load range tires at say 60psi, and you decided to put E range tires that have 80 psi stamped on the tire, then the placard would not be applicable for the new set of tires.

It really depends on tire design. Tires of the same design have the same load capacity charts for like sized tires. In other words, a tire sized ST225/75R15D has a maximum load capacity of 2540# at 65 psi. The same tire with a LRE capacity will provide the same load capacity at 65 psi for either tire. Industry standards do not restrict increases in recommended tire pressures, but, they are very consistent in saying to NEVER use less tire pressure than recommended by the vehicle manufacturer. However, the rims must be able to support increased load capacity, air pressures or both.

CW

p.s. Tire manufacturers have no control over recommended tire pressures set by vehicle manufacturers. However, they do have control over who they sell their OEM tires to. Many ST tire manufacturers will advertise their tires as 100% capable of being aired to full sidewall pressures at all times. It is very unwise for any RV trailer owner to use less than what the tire manufacturer says is the best air pressure conditions for their tires - as long as it‘s above vehicle manufacturer recommendations.

[fla-gypsy]

My tire maker (Maxxis) has an inflation chart showing the capacity of my tires at different pressures which I use to dial in my E rated tires to the max wheel capacity.

[CWtheMan]

Originally Posted by fla-gypsy

My tire maker (Maxxis) has an inflation chart showing the capacity of my tires at different pressures which I use to dial in my E rated tires to the max wheel capacity.

This reference follows industry standards on just how tire inflation charts are supposed to be used. A key element is to “Never use inflation pressures lower than those printed on the vehicle placard.”

http://www.trucktires.com/bridgeston.../WeighForm.pdf

CW

[fla-gypsy]

Originally Posted by CWtheMan

This reference follows industry standards on just how tire inflation charts are supposed to be used. A key element is to “Never use inflation pressures lower than those printed on the vehicle placard.”

http://www.trucktires.com/bridgeston.../WeighForm.pdf

CW

Thanks for the info but I don't have Bridgestone tires I have Maxxis tires and will use their inflation chart which does meet the makers minimum requirements.

http://www.maxxis.com/trailer/traile...nflation-chart