tire load ratings 1

[JerryHig]

Heavy duty bus Tire load ratings at recc'd psi are listed on tires. What is absolute maximum tire can withstand before failure? Factor of Safety? where published?

 

[Xwheelguy]

I would tend to think the publication would depend on where the wheel is going to be used. e.g., if in US, then probably the Tire & Rim Association Yearbook.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.

 

[JerryHig]

Is there a site where the Yearbook can be viewed without having to buy the book?

 

[Xwheelguy]

Not that I am aware. Most technical documentation like that needs to be purchased, at least from my experience in the wheel industry.

Here's a link to the T&RA website, which lists the yearbook as well as some other documents/manuals which might have the information for which you're looking:

http://www.us-tra.org/traHome.html

If it were me, I'd give them a call and see if they might be able to answer the question over the phone in regards to the maximum inflation pressure and safety factors.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.

 

[GregLocock]

T&RA does include some tables on pressure vs load, and derating for speed, and max load.

However I'd cut to the chase and contact your tire manufacturer directly.


Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[CapriRacer]

A number of issues:

1) Tim, the OP is talking about tires, not wheels.

2) The recommended pressure is NOT listed on the tire. The maximum pressure is!

3) There are circumstances where is it permissible to use more than the maximum pressure listed on the sidewall - but they are all situational dependent.

So why are you asking the question?

I can tell you that tire companies used to routinely burst test tires. However, it has become an exercise in futility as it yields no useful data and many companies have discontinued the practice as there is a certain amount of danger involved.

Tires are all about fatigue resistance, not a one time burst. We're talking millions of cycles here and a one time event is hardly germaine to understanding how well a tire is going to perform.

 

[rmw]

Most reputable tire mfg's are probably not going to divulge that information on the basis of the liability they would incur if some idiot decided to try to see if they could duplicate the results. What they do publish and emboss on the tire wall has adequate safety factors built in to them to keep them out of court if their recommendations are followed.

rmw

 

[GregLocock]

I guess it depends on how many tires you buy. Anyway the yearbook is only thirty bucks or so, as I said, it includes the sort of thing he's looking for.

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[JerryHig]

Thank you all for your input. The question was raised because a portable set of lifts is being used to lift a transit bus and the lifting forks only contact the outer tire of the dual rear tires. This potentially overloads the outer tire. However the tire manuufacturer has increased the rating for this circumstance only. Also, a response was recievd from the TRA and they do not publish saftey factors for this application, it is up to the tire manufactuerer

 

[Xwheelguy]

Capri,

I was well aware of that from the start. If you're referring to my initial posting...well, wheels usually aren't used on vehicles without tires are they? Post #2: Inflation pressure isn't a wheel 'characteristic'....so not sure what you felt was an issue with any of my responses.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.

 

[CapriRacer]

Sorry, Tim.

It's kind of a gut reaction on my part. I frequently get "taken to task" for using the term "rim" where some folks think the term ought to be "wheel".

I was actually reacting to the fact that the OP asked about tire load ratings and you came back with ".....I would tend to think the publication would depend on where the wheel is going to be used......".

I realize it is common for folks to use the term "tire" and "wheel" pretty much interchangebly.

In retrospect, I just should have let it go uncommented on - but my OCD was kicking in.

 

[Xwheelguy]

I figured it was the first post of mine. It's not a big deal Capri, I was just curious. I'm not too sure what governs which of the standards are to be used for either part...the wheel, the tire...one of those chicken or the egg situations I guess. To be honest, I didn't intend to type wheel....however, old habits are hard to break.

Thanks for responding.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.