Tire Tread Direction
 

Which side of the bike is the label of this tire supposed to be on? A friend and I were having a discussion about this the other day and we have our tires set up in opposite directions. Basically, what's the rolling direction?

http://www.nytro.com/photos/ZZ1851-2.jpg

If that is a directional tire it should have an arrow (like this <-----------) on one side of the side wall.


This arrow indicates the direction tire should be moving when you go forward.


Install so that when your bike is level and upright, the arrow is pointing UP when it is on the rear side of the wheel, or DOWN when it is on the front side of the wheel.

OR

Install so that when your bike is upside down, the arrow is pointing DOWN when it is on the rar side of the wheel, or UP when it is on the front side of the wheel.




If there is no arrow then it's not a directional tire, or else it's not DOT approved. Usually all tires except prototypes will have an arrow if they are directional.

I believe it's right hand or drive train side for the label, coinciding with the valve stem.

http://www.sheldonbrown.com/tires.html

There's really no functionality to road treads though.

In other words, unlike car tires bike tire treads don't pump water so they aren't directional. It's possible for a carcass to be directional, but that would be well indicated on the tire.

Label on the drive side, centered on the valve stem is the traditional way to do it.

I disagree with that. Water yea. But what about a patch of sand on a perfectely road like road with black smooth asphalt?


Even if you hit it straight you will go side ways. Threads provide traction. More so when you taking turns over something like that.


Gum, sand, dirt, you see all those things on the road. Threads are important. Besides, often time you don't just ride asphalt or concrete. Sometime you ride some very smooth surfaces, such as rails, red beauty bricks, painted concreate, lane markings. When those are wet, and if you on the slick you gonna slide.

Sliding is reduced when you have treads.

And pigs MIGHT fly!

I put my label on the drive side. I use a kickstand, so the bike leans to the left and I air the tires from the drive (easier) side. Makes sense to have the label there to locate the valve stem quicker with my poor eyes.

I never said that they didn't. (Conversely, never said that they did.) The question is, are bike treads directional?

Sand etc. isn't liquid and the treads don't act as pumps as do the directional treads on a car.

Besides, the bottom line is that if manufacturer intended the tire to rotate in only one direction, it would be marked clearly on the tire.

Makes the garage door pictures prettier too. ;)

That's an assumption and not a fact.


To prove your assumption right or wrong one must try to get their bike to the limits while mounting tires one way and the other.