This is Why Bike Tires Have Hairs on Them

Bikes’ tires are widely known as tires with small rubber threads on the outer surface. You might have seen tires with hairs on them, even asked yourself the reason for their existence. A good number of people have the notion that these hairy rubbers reduce noise or show wear.

When you see those little rubber hairs on the sides of a bike tire, just remember that they’re actually a byproduct of tire manufacturing! Those hairs are the remaining holes left over from all the rubber that was forced into the mold. These hairs are rubber, but they are non-structural.

However, the purpose of the little rubber hairs has nothing to do with reducing noise or showing wear. They won’t compromise the integrity of the tire’s tread pattern. It’s particularly noticeable when tires are molded using black or dark-colored rubber.

But the hairs are not there to help the tire meet performance or durability criteria. Instead, the hairs are there to remind you that a tire is new. You can refer to them as “vent spews” in technical terms.

How are bike tires manufactured with Vent spew?

The tire manufacturing process goes through a lot of steps to result in a complete tire. The rubber hairs, the round bumps on a tire’s surface, are created at specific points during the process. It is a lengthy and complicated process where the rubber is processed.

 The primary aim of the entire process is to fuse rubber with other materials. This is by a continuous extrusion of rubber granules from a hopper into a heated mold. Here is a brief tire manufacturing process for the same.

Step 1

The tire manufacturing process starts with a manual material feeding system. In this operation, the raw rubber is placed into the extrusion machine on a precise schedule. The timing and speed of this process is important because the rubber must be in position when it’s needed. The computer controls the precise time and speed of this process by using a program.

The resulting rubber blend shape is molded to resemble a real tire once you get the right plastic, nylon, and rubber ratio. Raw rubber, or “green tire”, demands the most labor-intensive process in making a tire. It also requires the most attention to detail.

Step 2

The green tire is then transferred into an autoclave. A pressure device molded like a clamshell from the inside but with the manufacturer’s tire patterns. After putting in hot air at 280 degrees to soften the rubber, vulcanization is done by injecting hot liquid rubber. The heat changes its properties permanently, which allows it to harden when cooled down.

Step 3

The air pressure applied causes air bubbles to form in the rubber tire. During the molding process, the tire-making machine forces trapped air to escape. The air then escapes via vents. We call these tiny hair-like projections on fresh tires after cooling down and solidification — vent spews or hair.

You may see them on your bike tire or truck wheel after it is cycled through a few times.  Still, most people believe it is caused by imbalanced thermal contraction and expansion of the physical structure of the polymer chains. Which reverts into their original state once cooled down.

Should you cut the hairs on the bike tires off?

If you decide to get rid of the hairs, you have two choices. Leave them on (if you plan to sell the bike), or cut them (if you plan to ride the bike).

If you decide to cut it, you will need to use a knife, which can be dangerous. If you are not too careful, you can accidentally cut yourself. In contrast, if you leave them uncut, they will eventually wear off.

How to Check Your Bike Tires for Wear and Add Air

Whether riding your bike to the office or just out for an excursion, it is important to have the right tire pressure. That being said, if your bike’s tire pressure is too low or too high, then you are putting yourself in danger. Remember, lower tire pressure offers less grip. As a result, riding over bumps will cause you to lose your balance and much more.

Not having enough tire pressure also extends the distance of your excursion much further than if you were to have any amount of air left to your tires. And finally, riding with low tire pressure increases the chances of a flat tire. You’ve probably got one, maybe two, tires that you pump up regularly as a cyclist. Maybe there are even two pumps, but that’s about it.

But here’s the thing: your tires are going to get flat, so you might as well learn how to do it correctly. And learn it you will, whether you like it. Even if you never ride with a pump, eventually, you’re going to buy one of those cheap floor pumps that come in a portable toolbox. Or, if you’re really lucky, you’ll get a floor pump with a gauge. It doesn’t matter which. But, first, you are going to have to learn how to inflate your tires.

With proper inflation, your tires will provide more traction, comfort and even save you money.

Bike Tire Maintenance Practices

Bicycle tires are exposed to a lot of wear and tear. Tires that are ridden regularly will tend to wear out faster than tires that are only ridden occasionally. Regular tire maintenance can help extend the overall life of your bicycle. Tires that are well cared for will last significantly longer than tires that aren’t cared for properly.

Here are maintenance practices you can put in place to increase the durability of your bike.

Clean Your Tires Regularly

Once clean, wash off the tire with the hose, or spray it lightly with a garden hose. Then dry it. If the tire has cracks or cuts, consider replacing it. When rubber tires become worn, they don’t grip the road, and slippery spots on the road are more dangerous.

Once tires are dry, check for cracks. Look for any cracks that metal particles, which can come from road debris, sharp objects, or even nails, may cause. For example, front tires may have cracks caused by impacts with curbs and potholes, and back tires may have cracks caused by effects with potholes.

Look for small cracks, too. Even tiny cracks can let water into the tires, which can lead to blowouts. Next, check the tire’s tread depth. Use a tread gauge, available from bike shops. The tread depth should be around 1⁄4 inch on most tires, but check your owner’s manual for the maximum depth.

A tire with a worn-down tread will grip less. Since that is the goal of a bicyclist, you’ll want to replace the tires when they lose their tread.

Use Tires Suitable for the Terrain

For off-road usage, the best tires for mountain bikes are mountain bike tires. These tires are made from a harder compound and are better able to withstand punctures and rough terrain. The tread pattern of these tires is also designed to grip the terrain better.  If you are going to ride your bike on terra firma, you need these tires.

It is tempting to think of mountain biking as just a way of riding your bike on rough terrain. But as with most things, it is more complicated than that. Mountain bikes are engineered for going downhill and jumping over things. However, some mountain bikes can also ride fast on good roads.  Either because the road itself is good enough or mountain bikes with front suspension can lean into corners.


To maintain the tread on bicycle tires, manufacturers sometimes shave rubber from the tread. That seems obvious, but the way it works is surprising. The shaved tread doesn’t slip on dry roads. On wet roads, though, it slides around. The shaved tread doesn’t grip better on dry roads because it doesn’t grip at all.

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