Rolling Resistance

[RWebb]

http://www.nytimes.com/2013/02/17/automobiles/more-traction-for-fuel-efficient-tires.html?hpw&_r=0&gwh=F66905174E6473A23EE1E573CA735409

[john70t]

Tires could use some efficiency ratings.
I'm surprised this has never been addressed.

[legion]

How could you possibly have low rolling resistance and high traction? The are two different words for the same thing.

[RWebb]

no, they aren't

read the article and you'll see they are addressing waste heat from one type of squirm

[asphaltgambler]

How about weight? I'm suprised at the people in the industry who do not know how heavy (Mass) a run-flat tire is compared to standard. Less rotaing weight = better performance and fuel economy

[sammyg2]

With current technology reducing rolling resistance usually means giving up traction, and no one wants to sell a tire or drive a car that is less safe just to get a few more MPG. Well almost no one, there are some huggers out there that are allergic to logic.

Tire manufacturers have been dumping a butt load of R&D money into developing some "revolutionary" tire for decades.
The only one that showed any promise was the air-less tire, but cost is prohibitive along with some other performance give-aways.
Tweaking materials and tread design has helped but I'm a bit sketical we'll see anything as revolutionary as the radial tire anytime soon.

When they went from bias ply to radial the traction and mileage improved.

[RWebb]

is it really that hard to read the article?

[romad]

It would be nice to see some data, article just said there is an improvement. How much? Compare to what? Obviously there is parasite friction and heat dissipation issues that still can be addressed.
Traction and rolling resistance are explaining the same thing, just one is negitive and the other positive. Theoretically, in a perfect model these two elements, grip and roll resistance, are directly related.

[kaisen]

Originally Posted by romad

It would be nice to see some data, artilce just said there is an improvement. How much? Compare to what? Obviously there is parasite friction and heat dissipation issues that still can be addressed. Theoretically, in a perfect model these two elements, grip and roll resistance, are inversely related.

Theoretically, perhaps

But lateral grip and radial efficiency are two very different dynamics, and both have a long way to go before they reach any kind of theoretical maximum where one would have to give up for the other

[sammyg2]

I read the article and filtered out the maybes and the pretends and the hopefullys and somedays.
Wasn't that much left after other than

"Tweaking materials and tread design has helped but I'm a bit sketical we'll see anything as revolutionary as the radial tire anytime soon.
"

[romad]

I had to correct my statement ..... traction and rolling resistance are directly related, typing to fast.

Anyways I'm not a tire engineer, but I would think discusses of rolling resistance are limited to just one vector. Adding the physics of the turn really introduces many changing variables.

[john70t]

Breaking down the properties and characteristics of tires into a graph is simple:
-Exposure to light and heat over time
-Traction characteristics at x angles given normalized spring/summer/winter/extreme winter.
-Traction response at x degree/changes in road undulations.
-Tire slip with the above (sideways=bad, forward=good)
-Temperatures throughout testing.


The manufacturers probably have all that data already.
Tire science is not new.

[Zeke]

If you've ever pushed a Sprint Cup car on level ground when Daytona or Talladega tires are mounted, you would understand that there is very little rolling resistance and the traction is certainly adequate. If you barely lean on the back of the car it will roll.

[RWebb]

Originally Posted by romad

It would be nice to see some data, article just said there is an improvement. How much? Compare to what? Obviously there is parasite friction and heat dissipation issues that still can be addressed.
Traction and rolling resistance are explaining the same thing, just one is negitive and the other positive. Theoretically, in a perfect model these two elements, grip and roll resistance, are directly related.

likely proprietary

[john70t]

Here is the tire of the future:
Micro fabrication on the micro or molecular level, using the properties and inspiration of shark skin, which has a directional bias.

commercial sez "SHARK TIRES BITE" (tm not pending)