Why do tires have little rubber "hairs"?

Car tires are crucial to ensuring road safety.

Oliver Thansan
Oliver Thansan
13 December 2023 Wednesday 10:42
4 Reads
Why do tires have little rubber "hairs"?

Car tires are crucial to ensuring road safety. They are the only element of the entire vehicle that is in direct contact with the asphalt. For this reason, we must check them and keep them in good condition at all times, since a damaged tire can cause an accident at any time.

In addition to periodically ensuring that its pressure is adequate - which will provide us with a balance between fuel consumption, driving comfort and braking safety - we must inspect the surface of the rubber to check its level of wear and make sure that there are no stuck objects, cuts or deformations that could put the safety of the occupants at risk.

And it is precisely when we have to change the wheels or when we buy a new car that we can more easily see the detail on which this article focuses. These are a kind of rubber "hairs" that new tires have and few drivers know the reason why they are there. We solve this doubt for you.

It is likely that you have ever wondered if these types of rubber mustaches have a specific purpose. There are rumors that say that they serve to ensure better grip with the asphalt, others that allow us to know if that tire has been used previously, and there are even those that attribute an aerodynamic effect to it. However, the existence of these small pieces of rubber does not serve any of these purposes, since they have no effect - neither positive nor negative - on driving.

First of all, we must know that these hairs are usually distributed both on the tread and on the side of the wheel. Likewise, its size may vary depending on the type of tire and the manufacturer, even on the same rubber. And its existence is simply due to the tire production process.

To manufacture a tire, it is necessary to subject it to very high pressures and temperatures. Both the rubber and the metal elements that give rigidity and shape to the wheel are introduced into a metal mold. This is subjected to high temperatures and a lot of pressure in what is known as the cooking phase. As the pressure and temperature increase, the rubber goes into a liquid state and forms the tread, the sidewalls and the entire final shape of the tire.

After applying heat and air, there is a risk of bubbles forming between the rubber and the mold. So that the rubber takes up all the space and there are no vapors or bubbles inside - which would compromise the safety of the wheel - the molds are provided with tiny holes so that air can escape. Holes through which small pieces of injected rubber also escape, which then harden and remain stuck to the tire. And this is how these "little hairs" are formed.

As we have already mentioned, these little pieces of rubber have no function. It is likely that in some cases they serve as an indicator to determine whether a tire is new or not, although it is not a completely reliable method either, since there are manufacturers or dealers, especially high-end ones, who choose to eliminate them before putting them on sale. sale considering that they are a production defect.

In fact, after driving the car for a few kilometers, we can see that the whiskers on the tread are disappearing and only a few remain on the sides. Removing them or not then becomes a matter of taste. Some people remove them for pleasure; others because they consider it not attractive. What is evident is that there is no reason that requires it for security or efficiency.

It is also not true that removing these whiskers is bad for the wheel. In any case, if we decide to eliminate them, we must take into account the way to do it. The most appropriate thing is to remove them directly with your hands and without using objects such as blades or scissors, as this could cause damage to the tire sidewall.