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Old 12-06-2018, 02:56 PM   #31
CWtheMan
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Inflating tires on your trailer to the load carried is not the way it’s supposed to be done. That method comes from the commercial carrier industry and is really not applicable for vehicles, such as yours, built under the guidance of FMVSS.

Here is an excerpt from the RV section of the USTMA.

“Inflation pressure recommendations may also be determined based on the tire manufacturer’s specifications, which define the amount of inflation pressure necessary to carry a given load. These inflation pressures may differ from those found on the vehicle tire placard or certification label.”
“However, never use inflation pressures lower than specified by the vehicle tire placard, certification label or owner’s manual. Nor should inflation pressure exceed the maximum pressure molded on the tire sidewall.”

In accordance with tire industry standards, inflation pressures for replacement tires must first be set to an inflation pressure that will ensure they provide a load capacity equal to or greater than what the Original Equipment tires provided.
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Old 12-06-2018, 07:26 PM   #32
Tireman9
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I have made it quite clear in my blog. Motorhomes can adjust their inflation based on the actual measured load but multi-axle trailers should run the pressure associated with the tire max load.
This is not the same as considering you are throwing money away.


InterplyShear is the primary cause of belt separations in trailer application and you should run the higher pressure than what is needed to support the trailer load as this will lower, but not eliminate the Interply Shear in your tires.


Sometimes Finite Eliment analysis is not something that can be equated to gut feel.
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Old 12-07-2018, 04:30 AM   #33
jadatis
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@ tireman 9


Does this interply- sheer story also goes for 1 axle trailers?
I asume trailers in America only have 2 axles or more. But in Europe most of the travel- trailers have 1 axle , and tandem- axle trailers are exeptional
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Old 12-07-2018, 07:57 PM   #34
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Quote:
Originally Posted by jadatis View Post
@ tireman 9


Does this interply- sheer story also goes for 1 axle trailers?
I asume trailers in America only have 2 axles or more. But in Europe most of the travel- trailers have 1 axle , and tandem- axle trailers are exeptional
Single axle trailers probably have higher interply shear than a motorized but I don't have the data or other evidence such as a film showing the lateral bending of the tires as seen on my post in my blog on Interply shear.


Side bending would be proof of higher InterplyShear. I just can't put a number on how much higher.


The Vehicle simulation software and the Finite Element software to calculate the level costs about $300,000. I was lucky to get a single run after hours while working but since I am now retired do not have access to the software anymore.
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Old 12-08-2018, 03:18 AM   #35
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For good understanding, ply-shear is courced by sideward to the driving direction forces when cornering. Or did I understand wrong.
Forgive me then, English is not my native language, sertainly not the technical English.

That is the reason why I dont expect lateral forces being that large for single axle travel trailers.
Because those turn around the same centre as the rear- and front-wheels of towing vehicle.
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Old 12-08-2018, 10:16 AM   #36
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Originally Posted by jadatis View Post
For good understanding, ply-shear is courced by sideward to the driving direction forces when cornering. Or did I understand wrong.
Forgive me then, English is not my native language, sertainly not the technical English.

That is the reason why I dont expect lateral forces being that large for single axle travel trailers.
Because those turn around the same centre as the rear- and front-wheels of towing vehicle.
I agree. You can learn more about the Interply Shear by reading the couple posts on the topic in my tire blog.
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