Places to go to learn about wheel/tire design and theory?

[69GTX]

A friend of mine asked where he could go to learn more about wheel and tire design/theory. He likes stock equipment, but wants to know a lot more.......and not the usual pitches from wheel or tire makers. In particular he's focused on 1995-2005 Toyota & Lexus for which he has several cars. Tire and wheel science, some engineering & design understanding, etc.

This forum is more about tire and wheel application to particular cars - general maintenance and performance. If anyone has some blogs, books, articles that are on line, I'd appreciate some references. Thanks.

 

[knerml]

https://www.tiresociety.org

 

[CapriRacer]

I can talk about tires.

I'm assuming your friend wants to do this on-line. That makes it kind of difficult as the tire industry is highly competitive and lots of technical stuff is considered proprietary, so things tend not to be published until much later - and by that time, everyone who needs to know already knows, so there's no point in publishing.

There is a book -
NHTSA: The Pneumatic Tire This is at times very theoretical and difficult to wade through. It is not at all user friendly and doesn't contain the kind of practical information the average joe is looking for.

If your friend is willing to travel, there are conferences where they teach a course on the fundamentals. I've seen it offered as part of ITEC - International Tire and Exhibition Conference - usually held in the Akron, Ohio area.

On the other hand, I'm here with very little to do and am willing to answer questions. I also have a website that might be useful. (See below)

 

[Kestas]

Perhaps the SAE organization can help. They may have books and hold workshops on these subjects.

 

[oil_film_movies]

Start with https://www.rimsntires.com/specspro.jsp . Play with it to understand geometry and fitment of various offsets, diameters, widths, etc., necessary to understand as the first fundamental tech lesson. Its very practical when considering aftermarket wheels & tires of various sizes, preserving much of the OEM suspension forces.
For example, one can use all that geometry to begin to understand the efffect on negative scrub radius & toe settings. (google that)

After that, assuming one understands physics (Newton's Laws) with applied engineering (Statics, Dynamics), you can start to study why wheels & tires are constructed as they are.
You can skip the physics/engineering aspects if you only want to study the structure & materials used in tires & wheels. How deep you go will depend on your background in engineering, but one can just get the basic idea of what these things look like anyway without years of education.

 

[69GTX]

Thanks for those inputs guys. They'll get passed along. That may be enough. And thanks CapriRacer to take on individual questions.

I found this nearly 20 yr old article by Bajer. But a lot of good basic information.

Jacques Bajer tire engineering article

 

[69GTX]

For Barry or others. I asked my friend if he specific questions and he came up with these.

(1)Are "factory" wheels, generally speaking, stronger, more capable, than they have to be, need to be, to meet the minimum standards the automaker, needs, for that vehicle? Same question for tires?

(2)You see remanufactured, cosmetically restored, wheels, for sale on ebay, everywhere. How safe, or unsafe, can these be? Are there any standards, for what can be brought back to life, vs not saveable? How do you know, what was done, to cosmetically, restore a wheel?

Everybody, wants bigger wider wheels, with lower profile tires. However, I'd like to switch my Lexus GS wheels, from 16x7.5 to 16x6 to save weight, and allow that same wheel/tire combo, to be used on either my 1999/2000 Toyota Avalons, or my Lexus GS cars (1998-2000 ).

(3) For my Lexus GS cars, what will I "give up", when I go to a narrower, lighter wheel, from a heavier wider wheel, and yet continue to use the exact same tires? I'm switching from 16x7.5 Aluminum ( stock on Lexus GS 1998-2005 ) to 16x6, Aluminum ( optional/stock on a 2000 Avalon ) ,,, both wheels, are ET45, 5x114.3, both are stock, Lexus/Toyota Wheels, from the 2000 model year... The tires stay the same, at 215/60/16(V).

(4) generally speaking are factory wheels simply a commodity, or do certain car manufacturers, pay more, to have better wheels made?

(5) Same question for tires...

(6) Are higher speed rated tires, going to hold up longer, and be safe longer, than lower speed rated tires, if all other variables are equal?....... in regards to tires that dont get a lot of use, and still have lots of tred remaining, but are now older than 7 years, old?

(7) Tires older, than 7 years old, that sat down in a spare tire well, under the trunk floor, but look absolutely brand new, feel brand new, etc, and have never been on the ground... Generally speaking, are they still safe to use, now, being 8-20 years old ?

 

[69GTX]

I think I could answer the last few questions.

4. No.....and Yes, some pay more to have better wheels made.
5. same for tires. Some mfg's pay more to have better tires made. Though some of these "special" OEM performance tires seem to be clunkers from the start where owners can't wait for them to wear out so they can put on better tires. For cars like Vettes you seem to hear this a lot, run flat tires, etc.

6. Don't think higher speed rated tires hold up any longer. If anything, they might be compromised earlier to due to abuse, inability to handle wide temperature extremes, etc. Manufacturers like to bail on tires by around 5-6 yrs. Some might allow up to 10 yrs for tires that were kept under ideal conditions and little contact to temp/UV/ozone extremes. My Goodyear Eagle F1's were on my Camaro for 16 yrs and 15K miles. I only took them off for "best engineering practices" and "potential liability" if an accident ever occurred on the highway. They looked fine inside and out, were supple, and had 40% tread left. I might go 10 yrs on my current BFG Comp2 summer tires but probably won't go further.

7. Safe to use? It depends. Some probably are very safe to use. But try to get a tire mfg or auto dealer to certify that for you....good luck. Personally, I wouldn't worry about a spare tire being over 7 yrs old as if it gets used it will be in an emergency with the intent of just getting you home. You'll be on guard. Then you can get the other tire fixed and put the spare back in the well again.

 

[oil_film_movies]

Originally Posted by 69GTX
(3) For my Lexus GS cars, what will I "give up", when I go to a narrower, lighter wheel, from a heavier wider wheel, and yet continue to use the exact same tires? I'm switching from 16x7.5 Aluminum ( stock on Lexus GS 1998-2005 ) to 16x6, Aluminum ( optional/stock on a 2000 Avalon ) ,,, both wheels, are ET45, 5x114.3, both are stock, Lexus/Toyota Wheels, from the 2000 model year... The tires stay the same, at 215/60/16(V).
You give up turning agility going narrower. Yes, a 215/60r16 tire can accept 6" to 7.5" width wheels as the allowable range for most tires of that size; that's the good news. More good news: Narrower wheels result in a slightly softer ride.

 

[CapriRacer]

Originally Posted by 69GTX
(6) Are higher speed rated tires, going to hold up longer, and be safe longer, than lower speed rated tires, if all other variables are equal?....... in regards to tires that dont get a lot of use, and still have lots of tred remaining, but are now older than 7 years, old?

--Yes, higher speed rated tires are more durable (cycles to failure) - all other variables equal. The other big factor in durability (cycles to failure) is heat. Hot climates cause more rapid oxidation. So the idea that there can be a single time limit on tires just isn't realistic.


(7) Tires older, than 7 years old, that sat down in a spare tire well, under the trunk floor, but look absolutely brand new, feel brand new, etc, and have never been on the ground... Generally speaking, are they still safe to use, now, being 8-20 years old ?

-- That depends on where you live. For some places - like Phoenix, a 7 year old tire probably won't last long. But take the same tire in Minneapolis, and it's a different story.

And tires stored near the exhaust pipe - like on some pickups, they could be unsafe sooner than the tires on the ground.

 

[69GTX]

Thanks Barry/CapriRacer and Oil_Film_Movies for those replies. Most appreciated.

 

[CapriRacer]

Originally Posted by 69GTX
Thanks Barry/CapriRacer and Oil_Film_Movies for those replies. Most appreciated.


Have your friend become a BITOGer. That way, you don't have to play intermediator.

 

[69GTX]

Originally Posted by CapriRacer
Originally Posted by 69GTX
Thanks Barry/CapriRacer and Oil_Film_Movies for those replies. Most appreciated.


Have your friend become a BITOGer. That way, you don't have to play intermediator.



I've posted some questions here for him a few times in the past several years. So it's very infrequent. He knows he can join up though.