High Performance vs Ultra High Performance Tires

[GC4lunch]

Originally Posted By: Rand
You constantly miss the point GC4lunch

Actually, you have demonstrated in several places in one posting that it is you who have missed the point.

Originally Posted By: Rand
Why dont you list the dry and wet stopping distances of summer tires..

If you had bothered to, like, R-E-A-D the post that you are criticizing, you might have noticed that I cited two sets of tests conducted by Tire Rack using the same vehicle on the same course. One test suite compared four all-season tires; the other compared four non-all-season tires (there is no tire industry category for "summer tires"). Both tests compared the dry and wet stopping distances of the tested tires, The all-season tires had longer stopping distances in the dry; the all-season tires had longer stopping distances in the wet. Most importantly, the difference between the dry stopping distances and the wet stopping distances for every all-season tire was greater than the difference between the dry stopping distances and the wet stopping distances of every non-all-season tire.

Originally Posted By: Rand
oh wait their WET stopping distance is longer too..

As specifically noted in my posting. Oh wait -- you cannot read.


Originally Posted By: Rand
The average of the 4 summer tires took about 22% longer to stop in the wet vs dry.

Actually, as noted in my posting -- I even bold-faced the numbers for you -- the actual difference for the four non-all-season tires were respectively 16.9 percent, 18.3 percent, 19.9 percent, and 17.2 percent. Oh wait -- you cannot read. Apparently you cannot do arithmentic, either, because the average of 16.9%, 18.3%, 19.9%, and 17.2% is not 22%, and not even "about 22%."

Originally Posted By: Rand
you dont compare wet vs dry traction directly

you would have to compare the same tire with and without silica

Leaving aside the obvious question of why I would have to compare the same tire with and without silica, you have set up an impossible condition. When a tire is made, the finished tire either has silica in it (about 99.9% of the tires made for passenger car use today do have silica) or it does not: you cannot simply add or subtract silica from a finished tire. However, the test reports I posted did show the results for the non-all-season Michelin Pilot Super Sport and its direct all-season counterpart in the Michelin line-up, the Pilot Super Sport A/S 3. The reports did show the results for the non-all-season Continental ExtremeContact DW and its direct all-season counterpart in the Continental line-up, the ExtremeContact DWS. The reports did show the results for the non-all-season Bridgestone Potenza S-04 Pole Position and its direct all-season counterpart in the Bridgestone line-up, the Potenza RE970AS Pole Position.

Oh wait -- you can't read.

But this discussion is not about tires with silica vs. tires without silcia, and -- except for some fanciful and, frankly, seemingly dishonest, comments by another poster here, the presence (which may be assumed) or absence (unlikely) of silica in a tire compound is quite beside the point. The discussion is about the inferiority of all-season tires -- as a class -- in wet braking, compared to non-all-season tires (as a general class, and excluding such specialty niches as Extreme Performance tires, racing slicks, M&S off-road tires, etc.).

Originally Posted By: Rand
ALL tires take longer to stop in the wet.

Of course. But the poster whom you are trying to support said the opposite a few posts up, and my post, which you purport to disagree with, contradicted him -- that is, I pointed out that all tires have longer stopping distances on wet pavement than on dry pavement, and I cited actual test numbers in support. Oh wait, you cannot read.

Originally Posted By: Rand
another thing you dont really touch on is.

Simplified:
hydroplaning resistance is mostly a function of TREAD PATTERN.
Traction is mostly a function of the Tread Compound.

You have simplified to the point of falsehood.
Hydroplaning is the phenomenon of the tire riding on a film of water that separates the tread from the pavement.
When the water can be displaced, that is, it can flow, then any tire with tread grooves that are shallower than the depth of water on the pavement will hydroplane, but a tire can hydroplane due to a built up wave (caused by the tire itself) even if the tread groove is deeper than the average depth of water on the roadway, and tread design can mitigate that phenomenon by angled and curved groves that will help steer the flowable water away from the tread area. In fact, the only function of patterns in the tread is to move water. If all roads were dry all the time, then all tires would be slicks with no tread pattern at all.
However, even without standing or flowing water, a tire can hydroplane if it retains a film of water on the tread; that water can still interpose a barrier -- a lubricating barrier -- between the tread of the tire and the surface of the pavement.

All-season tires -- all all-season tires -- are designed in a manner to make water stick to the tread. This is not a matter for argument: it is the definition of an all-season tire; it is what distinguishes an all season tire from a non-all-season tire. They are designed for water to stick to the tread because it is that property that allows the tire to have snow traction; without it, the tire will spin on snow -- which is exactly what non-all-season tires do in snowy conditions.
But because water adheres to the tread of an all-season tire, the tire can and does hydroplane even when there is insufficient water on the pavement to flow. That is the reason why all-season tires as a class have inferior wet braking to non-all-season tires.

 

[y_p_w]

Originally Posted By: GC4lunch
All-season tires -- all all-season tires -- are designed in a manner to make water stick to the tread.[/u] This is not a matter for argument: it is the definition of an all-season tire; it is what distinguishes an all season tire from a non-all-season tire. They are designed for water to stick to the tread because it is that property that allows the tire to have snow traction; without it, the tire will spin on snow -- which is exactly what non-all-season tires do in snowy conditions.
But because water adheres to the tread of an all-season tire, the tire can and does hydroplane even when there is insufficient water on the pavement to flow. That is the reason why all-season tires as a class have inferior wet braking to non-all-season tires.

I don't have an issue that you mention that all-season tires as a class tend towards slightly worse wet traction performance than summer tires. That's pretty obvious because the performance can be measured. I do have an issue that you attribute this to water adhering to the tread surface on all-seasons, because it simply isn't detrimental. Wet weather specific racing tires for motorcycles and race cars are intentionally designed for water to adhere to the surface, because it improves grip on wet surfaces. If you see any F1 race in the rain with intermediate or wet tires, the tread surface is thoroughly wetted and water isn't repelled like water from a duck's feathers.

Who am I going to believe? You who says that water sticking to the tread compound is detrimental to wet traction, or a company like Metzeler (owned by Pirelli) that claims that its wet-specific motorcycle racing tires have high wet traction for the the very reason that they absorb moisture.

 

[GC4lunch]

Originally Posted By: y_p_w
I don't have an issue that you mention that all-season tires as a class tend towards slightly worse wet traction performance than summer tires. That's pretty obvious because the performance can be measured. I do have an issue that you attribute this to water adhering to the tread surface on all-seasons . . .

Have you ever heard of Occam's Razor?

 

[y_p_w]

Originally Posted By: GC4lunch
Originally Posted By: y_p_w
I don't have an issue that you mention that all-season tires as a class tend towards slightly worse wet traction performance than summer tires. That's pretty obvious because the performance can be measured. I do have an issue that you attribute this to water adhering to the tread surface on all-seasons . . .

Have you ever heard of Occam's Razor?

Of course. There are varying interpretations, but the most basic is that all things being equal, the simplest explanation is probably the best. However, it's only an axiom and there's a whole lot about tire performance that isn't obvious in simple ways.

I thought that maybe I'd take a break from this thread, but I'm having too much fun. I specifically remember for my '95 Integra GS-R, once the OEM all-seasons (Michelin HGT-V4) were worn I got several summer tires only until it was stolen, recovered, and declared a loss after being stripped. I'd first started with Pirelli P6000 tires. Interesting when dry but odd when wet. The supposed "wave" pattern didn't seem to provide very good hydroplaning resistance and it would lift in small puddles at less than freeway speeds. After those were worn I got Dunlop SP Sport 9000 tires and rode them once. I liked them so much that I got another set, but this time I didn't rotate them until the fronts were worn to the TWI and I then got new tires for the rear (Yokohama AVS ES100) and rotated the backs to the fronts. However, in all that time there was always a simple observation. Water was absorbed by the tires when it was wet. So there's your practice. And there was always a worst case scenario when it came to wet traction for each and every tire I ever had on that car. It was front-wheel drive with lots of torque at the wheels. When it was wet I always had the most difficulty taking off if there was a painted road stripe, such as a painted crosswalk or a line at a stop sign. Never had an issue at one when it was dry because dry traction was enough. But when wet, it was a tire against water sliding against a hydrophobic surface. And much as that 1956 article described, it was horrible with regards to traction until the tires regained contact with the hydrophilic pavement.

There a lot more data points that back up that a tire adsorbing water at the surface is beneficial for wet traction. When there isn't actual hydroplaning but a boundary layer where the tread is in contact with the road surface, water is an aid. Water has cohesive properties. It actually holds together because of its polar properties. Drops of water hold together. Polarized solids hold to water and water holds to water - that's adhesion. That's why you can take a wet piece of paper to a wet surface and it will stick.

And I couldn't help linking to one more patent...

Quote:
https://www.google.com/patents/US5374671

Since the hydrophilic polymer has low water diffusivities, the hydrophilic property of the elastomer in wet conditions will be most apparent on the surface of the tread. As is known in the art, as the moisture content of a hydrophilic polymer is increased, there is a decrease in the glass transition (Tg) of the polymer. In wet conditions, the hydrophilic polymer absorbs water, and the properties of the polymer at the tread surface change, in proportion to the amount of water absorbed, to provide a softer, more tactile tread surface, thus improving traction.

 

[Rand]

apparently you cant read either. none of the summer tires you list qualify to your fact.

Potenza S-04 Pole Position
http://www.bridgestonetire.com/tire/potenza-s-04-pole-position
Quote:
A silica-rich performance compound molded into an advanced asymmetric tread


Michelin PSS
http://www.michelinman.com/tire-selector...rt/tire-details
Quote:
Pilot Super Sport features an asymmetric design molded of Michelin’s Bi-Compound tread rubber featuring a Le Mans-inspired dry compound outboard side-by-side with their latest generation of wet compound inboard. The low-void outboard shoulder features a track-type compound to withstand the stresses of high performance cornering while the notched center ribs and inboard shoulder feature a compound designed for superior performance at very high speeds and in wet conditions.


hint. inboard tread compound for wet...guess what that has in it.

Now onto the dunlop sport MAXX RT
... guess what this has in the tread...
http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=Sport+Maxx+RT
Quote:
Sport Maxx RT tires feature adaptive compound technology that uses motorsports derived polymers to allow its silica-plus tread rubber



and finally
Yokohama ADVAN Sport V105
http://media.unitedfuture-yoko.com.s3.amazonaws.com/1372699997-brouchure.pdf

Quote:
Micro Silca Enhances traction, Silica dispersant insures even distribution for consistant performance.


Quote:
ADVAN Sport V105 tires mold a Microsilica and Orange Oil enhanced tread compound that helps the tread rubber remain pliable to improve tire adhesion and grip. The compound is molded into an asymmetrical tread design in which wide outboard shoulder blocks and circumferential ribs work together to promote dry traction and handling. Variable width circumferential grooves and asymmetric lateral notches help reduce noise and promote water flow through the footprint to resist hydroplaning.


So... it has silica enhanced tread for wet grip, and notches and grooves for hydroplaning resistance...

Please find some summer tires without silica that have braking performance in the wet. Preferably better than these with silica(or your point isnt valid)

Or keep your head in the Silica

not arguing that SOME summer tires perform better in the wet and dry than SOME all seasons. but not because of some magical tread compound that's in summer only tires that repels water