Antenna tread — What is it and why tires have it

The tire’s antenna tread acts as a grounding strip to dissipate static charge

The thin line around the circumference of a tire is called the tire antenna tread. It is a conductive band of rubber that helps disperse static electricity as you ride so you don’t get a shock when you step off the bike or out of your car. Antenna tread is common, especially on the newest tires using modified rubber compounds that tend to insulate the vehicle from the road.

Why tires need antenna tread

The grounding tread is not a new technology but it’s become more important as tire makers have begun to use more silica in the rubber compounds. Adding silica decreases the tires’ rolling resistance to improve MPG and it also increases traction. These more energy efficient tires contain more silica but also less electrically conductive carbon black.

The lower amounts of carbon black is what’s causing the problems with static electricity buildup in the vehicle. In the past, carbon black in tires helped dissipate static charge. With the reduction in the use of carbon black, customers started to complain about static shock when moving in and out of the vehicle.

Why Tire Makers add Silica

The primary reason tire manufacturers add silica to tires is to improve the tire’s performance in wet weather conditions. Silica is used to provide flexibility through the buildup of low heat, which helps the tire maintain its grip on the road even in wet conditions.

Silica also enhances the tire’s resistance to cutting, chipping, and chunking. In the past, carbon black was used to improve the durability of tires. However, with the reduction in the use of carbon black, tire manufacturers have turned to silica as a replacement. Silica improves the tire’s durability and reduces fuel consumption by lowering the rolling resistanc.

Silica is also used to improve the tire’s performance in winter conditions. Winter tires require more than just a tread design to grip snow and ice well. Tire manufacturers have experimented with various methods to enhance traction, including increasing the void ratio and the number of tread blocks. However, they found that the tire tread was still lacking in stickiness. Mixing rubber and silica together was found to be a good solution to this problem. The silica content in the tire enables it to establish traction with the road surface seamlessly, even in harsh weather conditions.

Antenna tread is a solution to the problem of silica being a good electrical insulator. It is built into all motorcycle tire manufacturers’ tires, as well as car and truck tires. The visible line of antenna tread might fade or disappear over time, but it is nothing to worry about.

Tire makers add a carbon black strip

The solution to static buildup is a ground tread. At the center-line of the tire, tire manufacturers embed a thin continuous strip of conductive carbon-black-rich rubber so it’s always in contact with the road to dissipate static buildup.

For more information about tires and the antenna tread, see this post in Car and Driver

©, 2022 Rick Muscoplat