What are "directional" tires..??

[97tbird]

I'm new to this term..

--does anybody know what this means?
--how can you tell if a tire is directional or not?
--are there any special procediures to mount/balance "directional" tires?
--if there are, what are the effects of mounting them inproperly?
Can someone pls educate me about this?
Thanks.

 

[S2000driver]

Directional tires have a tread pattern that is different based on how you mount it on the wheel (two possible ways). When mounted properly, the directional pattern enhances traction, more often than not by expelling water in a pumping action. In this case, the tread will have a "V" shape so that as it rolls the tip of the V hits the ground first.

A tire is directional if it has an arrow on the sidewall with the text "ROTATION". When the car drives forward, the arrow moves the direction the tires rolls.

For directional tires, they need mounted on the proper side of the car. The people mounting the tires should be alerted that they are directional. After mounted properly, they must stay on the same side of the car during rotation.

Mounting them improperly will reverse the pumping action of the tires (from center to edges to pumping inward), which means your car will hydroplane sooner instead of later (speedwise).

quote:

---

Originally posted by 97tbird:
I'm new to this term..

--does anybody know what this means?
--how can you tell if a tire is directional or not?
--are there any special procediures to mount/balance "directional" tires?
--if there are, what are the effects of mounting them inproperly?
Can someone pls educate me about this?
Thanks.

---

 

[S2000driver]

Now once you digested "directional" tires, also be aware there is also something a little different called "assymetric."

Assymetric tires have a certain side that is to be mounted outward on the wheel. Mainly because the tire has a higher % of tread hitting the ground for good cornering ability. One side is marked "mount this side in" and the other side says "mount this side out". Again, the installer must be aware of which way to put the tire while mounting.

There is no restriction for rotation with assymetric tires, side-to-side is OK.

 

[Rick in PA]

Another way of looking for correct mounting of directional tires is to look on the top of the tire (when installed on the vehicle). The "V" should be pointed forward (toward the direction of travel).

 

[acranox]

And if you own a car like the NSX, with directional, assymetric tires, you never have to rotate them, because you can't. The fronts are smaller than the rears, and you can't swap sides because then the tires would be rotating the wrong way.

 

[S2000driver]

My S2000 is like that. The stock tires are directional and the front tires are smaller than the rears. Therefore to rotate tires you would have to have them removed from the rims, not worth the trouble and damage to the wheels. I had no problem getting even wear without rotation side-to-side, of course the rear tires wore faster.

For my S2000 winter tires, I chose Dunlop SP5000. These tires are assymetric but not directional. Therefore, I can swap the two fronts side-to-side, and the rears side-to-side, without taking them off the rims.

quote:

---

Originally posted by acranox:
And if you own a car like the NSX, with directional, assymetric tires, you never have to rotate them, because you can't. The fronts are smaller than the rears, and you can't swap sides because then the tires would be rotating the wrong way.

---

 

[VaderSS]

Picture is worth 1000 words...
Non-Directional, mount and rotate as you please

Directional, will have arrow indicating the forward rotation of the tire.

Assymetric, mount slick part out

 

[White Fang]

Great pictures VaderSS. Thanks for posting.

 

[97tbird]

to EVERYBODY who replied to my post: TKAN YOU.
Vader SS,
cool pics. thanks.

I think one of my tires(they ARE directional, btw: Yoko AVS db S2) are mounted wrong. going to the tire place again asap.