The MYTH Of Wider Tire Contact Patch Dispelled!

[CapriRacer]

Originally Posted by RidingOnRailz

Screen cap from that page. I did acknowledge the title, editor, and year it was published, in the topmost post.

So you bought the book?

[RidingOnRailz]

Originally Posted by CapriRacer

So you bought the book?

Why is this so important. Focus on the topic.

[CapriRacer]

Originally Posted by RidingOnRailz

Why is this so important. Focus on the topic.

I want to get a copy, but I don't want to spend over $150 to get it.

[CapriRacer]

Originally Posted by RidingOnRailz

Why is this so important. Focus on the topic.

I was going to do the math and make it presentable, but here are 2 webpages that show that wider = larger contact patch in an apples-to-apples comparison.

http://web.archive.org/web/201302090...on-tires-1.htm

https://www.tyrereviews.com/Article/...wide-tyres.htm

[RidingOnRailz]

Originally Posted by CapriRacer

I was going to do the math and make it presentable, but here are 2 webpages that show
that wider = larger contact patch in an apples-to-
apples comparison.

http://web.archive.org/web/201302090...on-tires-1.htm

https://www.tyrereviews.com/Article/...wide-tyres.htm

Well, you’re right.

But - that still doesn’t mean that the increase in patch area was that dramatic. Nor that I have to appreciate the effect it has on steering or other handling parameters.

I prefer the heavier, on-center steering feel of narrower, higher profile tires. I’m admittedly a twitchy driver due to issues at birth. So a car that tracks straighter and requires more effort from me to turn is safer, and explains why I want to fit the OEM size wheels and tires from the 2010 Honda Accord base LX onto my 2010 Accord up-trim EX. I have already confirmed they will fit.

[Stealthee]

So what you are saying is nothing has been dispelled and you are basing "results" on an opinion, rather than facts?

[RidingOnRailz]

Originally Posted by Stealthee

So what you are saying is nothing has
been dispelled and you are basing "results"
on an opinion, rather than facts?

Not entirely. I may have been wrong about the effect on contact patch area of wider low profile tires, at least according to Capri. But, I am not wrong about the effects of them on handling and ride, etc, especially what I consider to be two critical aspects: rapidity of steering response, and of self-centering force.

[CapriRacer]

Originally Posted by RidingOnRailz

Screen cap from that page. I did acknowledge the title, editor, and year it was published, in the topmost post.

I am curious: I ask where you got the book and you tell me you acknowledged the source, but that doesn't tell me where you got the book.

Perhaps I ought to word this differently: Did you borrow the book from the library, from a friend, found an on-line source, purchased it?

I want to get a copy, but I've seen the book listed for as high as $200 and I don't want to spend that kind of money without some assurance it has useful data.

[RidingOnRailz]

Originally Posted by CapriRacer

I am curious: I ask where you got the book
and you tell me you acknowledged the source,
but that doesn't tell me where you got the book.

Perhaps I ought to word this differently: Did you
borrow the book from the library, from a friend,
found an on-line source, purchased it?

I want to get a copy, but I've seen the book listed
for as high as $200 and I don't want to spend that
kind of money without some assurance it has
useful data.

Why does it matter? Sheez you sound like Don Imus on his radio program going on and on about the Whittaker Chambers and Hiss matter from the fifties.

Search Google Books and figure it out.

Your knowledge and contribution to the topic of this thread has been as usual quite welcome and helpful, but for God sakes stop obsessing about what methods I used to cite that page in a book! I travelled back in time and took a picture, ok?

[Blue Bowtie]

Originally Posted by RidingOnRailz

“ The only possible myth that could be dispelled is that wider = more surface contact”

Bingo!

And I hear it all the time on newsgroups and in moderated fora like this one:

“Get wider tires, more contact surface!” ...

One critical qualifier is missing from that statement. It would be important to mention "At the same inflation" because that is the only condition under which it is true.

As experienced people may have come to know, wider tires require less inflation to support a given load. THAT'S where the footprint increases and the traction advantage begins.

If you think that concept was just pulled from the dark side of Our Fearless Leader's personal space, check with aircraft operation manuals since Elizabeth was born, the remote inflation controls on off-road equipment going back to the 1930s, and similar systems (still in existence today).

The above statements might apply to the Continental 4-ply budget tires on your Toyonissahondubaruishi "sport" sedan, but are not universally true as might have been the inference made by many readers.

[RidingOnRailz]

Originally Posted by Blue Bowtie

(1) One critical qualifier is missing from that statement.
It would be important to mention "At the same inflation" because that
is the only condition under which it is true.

(2)As experienced people may have come to know, wider tires require
less inflation to support a given load. THAT'S where the footprint
increases and the traction advantage begins.

(3)If you think that concept was just pulled from the dark side of Our
Fearless Leader's personal space, check with aircraft operation manuals
since Elizabeth was born, the remote inflation controls on off-road
equipment going back to the 1930s, and similar systems (still in
existence today).

(4)The above statements might apply to the Continental 4-ply budget
tires on your Toyonissahondubaruishi "sport" sedan, but are not
universally true as might have been the inference made by many
readers.

(2) "wider tires require less inflation
to support a given load. "

I do have to wonder about that second paragraph. Because according to my research of tire pressure websites such as tirepressure.com, etc, a lot of car makers specify higher cold cold tire pressures on trim levels of models with wider, lower profile tires.

Take my 2010 Honda Accord, EX trim:

2010 Accord LX - tire size 215-60R16, cold inflation 30psi

2010 Accord EX - tire size 225-50R17, cold inflation 32psi

My contention is that higher pressure, at least 1psi, is needed to maintain full contact with the road across the full width of the wider rubber.

[RidingOnRailz]

A good example of why them wide schitz don't belong on daily drivers:

https://www.youtube.com/watch?v=lEnQwmTaQII&t=157s

Good for nothing but goin' sideways!

[CapriRacer]

"Wider tires .... all other things being equal."

OK, here's the problem with that statement: ALL other things CAN'T be equal.

If you go wider and don't change the aspect ratio nor the rim diameter, you go up in diameter and load carrying capacity.

If you try to keep the diameter and the load carrying capacity the same (or at least within a small difference), the aspect ratio and/or the rim diameter has to change.

Those 2 things can't be escaped from. So if you are trying to make a point about "wider", you need to indicate which of those is being defined as "wider".

So allow me to demonstrate: Wider tires have a larger footprint, all other things being equal (as best it can be done) - and it doesn't matter if "wider" = a larger diameter, or "wider" = same diameter, but lower aspect ratio and/or larger rim diameter. Both of those result in a larger contact patch.

[RidingOnRailz]

Originally Posted by CapriRacer

"Wider tires .... all other things being equal."

OK, here's the problem with that statement: ALL other things CAN'T be equal.

If you go wider and don't change the aspect ratio nor the rim diameter, you go up in diameter
and load carrying capacity.

If you try to keep the diameter and the
load carrying capacity the same (or at least within a small
difference), the aspect ratio and/or the rim diameter has to change.

Those 2 things can't be escaped from. So if you are trying to make a point about "wider", you
need to indicate which of those is being defined as "wider".

So allow me to demonstrate: Wider tires have a larger footprint, all other things being equal (as
best it can be done) - and it doesn't matter if "wider" = a larger diameter, or "wider" = same
diameter, but lower aspect ratio and/or larger rim diameter. Both of those result in a
larger contact patch.

Apologies: Both my father and I always had issues with context when we were communicating with others, so it wasn't always clear what we were talking about. We also had zero concept of something called a segue, or, verbal indication that we were about to switch subjects.


When I say "wheel/rim" or "tire", 90% of the time I'm referring to the whole package.

Whenever I say "wider" I am referring to the lateral width of both tire and the rim its mounted to. "Greater or lesser diameter" is self-explanatory.

So in that context(!) let me ask you this:

We have presently seen, over the last twenty years, the following trends:

Tires: given the same overall diameter, sidewall height has decreased, and tire width increased.

Wheels: Both diameter and width increased.


I have an alternative vision of what could have happened during that same time period:

Tires: Sidewall height decreases, but width remains the same.

Wheels: Diameter increases, but width remains the same.

Benefits: Stronger self-aligning/self-centering force preserved. Weight concentration of a narrower tire/wheel package down through rain and snow is maintained.
Aesthetics: Those who prefer to see less sidewall and more wheel have their needs met.

I hope this clears up some of the terms I have been using.

[fredjacksonsan]

Originally Posted by RidingOnRailz

A good example of why them wide schitz don't belong on daily drivers:

https://www.youtube.com/watch?v=lEnQwmTaQII&t=157s

Good for nothing but goin' sideways!

Almost ANY car with sufficient power can spin the rear (or drive) wheels.

I agree with some of your points, thinner tires generally track better and have more predictable handling. But probably not at the limit. And comparing how two different (make) cars handle and basing your proof on that, well, nope sorry.

But if you were right about thinner tires having a bigger contact patch, hell we'd all be driving on tires as wide as some road bicycle.

Your assertions have

1) not been backed up and
2) you're pretty much arguing an invalid position at this point and
3) I am wondering why you're having such a hard time just telling CapriRacer where you found the book!