Sorry - tire inflation questions.

[5picker]

These threads really shine a light on how many either can't read or comprehend what is written on the sidewall of a tire and/or on the inflation charts/stickers... or they simply choose to ignore it thinking they know better than the folks engineering the product.

Have a great day and best of luck.
Many are going to need it!

[babock]

Originally Posted by Teetime

I've thought the suspension would distribute the weight more equally

It does if you have leaf springs with an equilizer assuming the equilizer hasn't reached the end of its travel.

[TitanMike]

Originally Posted by Teetime

Just wondering, how many people split the scales to weight front and rear TT axles?

They are so close together, I don't know if I could do that without still having the rear of my TV still on the front scale...

I am able to "extract" individual axle weights by merely driving on the scale one axle at a time starting with the front axle on my TV and ending with the rear axle of the TT. The scale I use can accommodate my entire 48 foot length. I record the first axle's weight then record new reading as each axle joins the rest on the scale. From there easy to calculate individual weights by merely subtracting the total weights of axles weighed ahead.

I don't need CAT scales as I'm able to do this on a nearby State Patrol weigh station that is rarely attended but has the readout visible through the window.

If not a weigh station I could also use any number of local gravel/landscape product scales. Used a couple in the past and never had to pay.

[SailorSam20500]

Load tables are appropriately used for single axle trailers and all vehicles (not multi-axle trailers).
The load tables are a standard and apply to ALL tire manufacturers. There are three sets, one from each of the appropriate standards agencies.
For multi-axle trailers, this is on Roger's web site:


"Friday, March 29, 2019

It appears Goodyear agrees with me


I have written a number of times on the advisability of running trailer tires at the inflation molded on the tire sidewall.

Some posts dove deep into the Science behind the recommendation. I know this can make your eyes glaze over so how about just following what Goodyear says in their RV Tires information web page:

"Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up.""

Also:
"
Bottom line
In a number of posts I have recommended that Motorhomes set their inflation based on measured static load plus a margin of at least 10% additional PSI. This would also apply to single axle trailers. BUT for Tandem and triple axle trailers I strongly recommend that the tire cold inflation be set to the inflation molded on the tire sidewall associated with the tire maximum load capacity. I also recommend that the measured static tire loads on these trailers be no greater than 85% of the tire maximum with a 20% margin being better."

The above comments seem to be pretty unambiguous...

[babock]

Originally Posted by SailorSam20500

Load tables are appropriately used for single axle trailers and all vehicles (not multi-axle trailers).

That makes ZERO sense.

Where did you read this?

[Blackrock]

Caution Overload Light is on.

[ependydad]

Originally Posted by Blackrock

Caution Overload Light is on.

Tsk, tsk... language.

[ependydad]

Originally Posted by SailorSam20500

Load tables are appropriately used for single axle trailers and all vehicles (not multi-axle trailers).
The load tables are a standard and apply to ALL tire manufacturers. There are three sets, one from each of the appropriate standards agencies.
For multi-axle trailers, this is on Roger's web site:

So interestingly, he has written statements to the contrary - babcock quoted an article on RVTireSafety.net. Maybe he suggests using the load range tables only when upgrading the trailer tires to a higher load range?

[TitanMike]

Originally Posted by SailorSam20500

Load tables are appropriately used for single axle trailers and all vehicles (not multi-axle trailers).
The load tables are a standard and apply to ALL tire manufacturers. There are three sets, one from each of the appropriate standards agencies.
For multi-axle trailers, this is on Roger's web site:


"Friday, March 29, 2019

It appears Goodyear agrees with me


I have written a number of times on the advisability of running trailer tires at the inflation molded on the tire sidewall.

Some posts dove deep into the Science behind the recommendation. I know this can make your eyes glaze over so how about just following what Goodyear says in their RV Tires information web page:

"Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up.""

Also:
"
Bottom line
In a number of posts I have recommended that Motorhomes set their inflation based on measured static load plus a margin of at least 10% additional PSI. This would also apply to single axle trailers. BUT for Tandem and triple axle trailers I strongly recommend that the tire cold inflation be set to the inflation molded on the tire sidewall associated with the tire maximum load capacity. I also recommend that the measured static tire loads on these trailers be no greater than 85% of the tire maximum with a 20% margin being better."

The above comments seem to be pretty unambiguous...

What you say is correct but with one caveat. It's true as long as the actual tires used are the ones originally installed on the trailer by the manufacturer. Does NOT hold true when using tires one or two load ranges higher than what the vehicle was originally equipped with.

[mxtreme30]

So ya'll are saying if OP used the spare that is a load range under the rest of the tires that he'd match the air pressure in spare to the tire Katy Corner to the spare to equalize the load across the axles?

Don't worry I already changed my P-rated tires to LT tires on my TV and doubled my payload rating when I run them at max PSI!

Sorry...couldn't help myself!

[SailorSam20500]

Originally Posted by babock

That makes ZERO sense.

Where did you read this?

That's basically what Roger said in the second quote I copied. Motorhomes and single axle trailers can inflate based on the load tables - he recommends the minimum pressure for the static load plus at least 10% additional PSI. Multi axle trailers should run at max sidewall pressure. This assumes that the tires have sufficient capacity for the load.

Originally Posted by TitanMike

What you say is correct but with one caveat. It's true as long as the actual tires used are the ones originally installed on the trailer by the manufacturer. Does NOT hold true when using tires one or two load ranges higher than what the vehicle was originally equipped with.

Simply increasing the load range on the tires does NOTHING to alleviate the reason Roger recommends running multi axle trailers at max sidewall pressure: interply shear caused during turns. On my trailer, the OEM tires have a +30% margin over my actual static weight. So, possibly, I could go down a load range and still have sufficient capacity. I run the tires at max inflation.

[babock]

Originally Posted by SailorSam20500

That's basically what Roger said in the second quote I copied. Motorhomes and single axle trailers can inflate based on the load tables - he recommends the minimum pressure for the static load plus at least 10% additional PSI. Multi axle trailers should run at max sidewall pressure. This assumes that the tires have sufficient capacity for the load.

No..it's not basically what he said.

[babock]

Originally Posted by 5picker

These threads really shine a light on how many either can't read or comprehend what is written on the sidewall of a tire and/or on the inflation charts/stickers... or they simply choose to ignore it thinking they know better than the folks engineering the product.

Exactly!

[Airdale]

This thread is laced with so much disinformation I could never challenge any of it without writing numerous posts that would be disputed.

How come no one reads their vehicle owner’s manual? All of the correct tire inflation recommendations are in there. Many were mandated by NHTSA to be there.

Here is a reference with all of the correct information. Chapter #4 is dedicated to RV applications.

https://www.ustires.org/sites/defaul...TruckTires.pdf

[babock]

Originally Posted by Airdale

This thread is laced with so much disinformation I could never challenge any of it without writing numerous posts that would be disputed.

How come no one reads their vehicle owner’s manual? All of the correct tire inflation recommendations are in there. Many were mandated by NHTSA to be there.

Here is a reference with all of the correct information. Chapter #4 is dedicated to RV applications.

https://www.ustires.org/sites/defaul...TruckTires.pdf

The OP is going to a higher load range tire. The owners manual isn't going to help there is it? It's not the same size tire that came on the trailer.

[Airdale]

Originally Posted by babock

The OP is going to a higher load range tire. The owners manual isn't going to help there is it? It's not the same size tire that came on the trailer.

It is the same size, it just has more load capacity. At 50 psi it's identical to the OE tire. The OPs option is to use the same recommended inflation pressures or any option above that all the way to sidewall max.

The RVIA recommendation is to use an inflation pressure providing 10% higher load capacity than GAWR. I would use 15% if its available.

[babock]

I agree with that. Of course it has nothing to do with what's in the owners manual.

Originally Posted by Airdale

It is the same size, it just has more load capacity. At 50 psi it's identical to the OE tire. The OPs option is to use the same recommended inflation pressures or any option above that all the way to sidewall max.

The RVIA recommendation is to use an inflation pressure providing 10% higher load capacity than GAWR. I would use 15% if its available.

[5picker]

Originally Posted by Airdale

It is the same size, it just has more load capacity. At 50 psi it's identical to the OE tire. The OPs option is to use the same recommended inflation pressures or any option above that all the way to sidewall max.

The RVIA recommendation is to use an inflation pressure providing 10% higher load capacity than GAWR. I would use 15% if its available.

This entire post bears re-reading, especially the part about "The OPs option is to use the same recommended inflation pressures or any option above that all the way to sidewall max."

It really can be that simple.

[frank4711]

Originally Posted by 5picker

These threads really shine a light on how many either can't read or comprehend what is written on the sidewall of a tire and/or on the inflation charts/stickers... or they simply choose to ignore it thinking they know better than the folks engineering the product.

Have a great day and best of luck.
Many are going to need it!

I am with 5picker

[TowPro]

Originally Posted by clarkbre

My concern would be getting the trailer's front and rear axle weights equal.

Given that the tongue will carry approximately 10-15% of the overall trailer weight, the axles should be equal in load. Based on the above numbers, even with your WDH engaged, I'm guessing that your trailer may be slightly nose down on the ball? The tongue may need to be raised an inch or so to take some of the weight off the front axle and load a bit more on the rear.

this could also be a weight equalizer hitch pushing weight both the Tow vehicle front axles and the RV rear axle.