What does the radial of a tire mean?
2 Answers
Tire radial, also known as the meridian line, refers to the arrangement direction of the internal cord fabric of the tire at a 90-degree angle to the centerline of the tread, resembling the meridians on a globe. Below is relevant information: 1. Introduction: Radial tires (radial-tire) are a type of tire structure, different from bias tires, arched tires, and pressure-regulating tires. The international code for radial tires is "R", commonly known as "steel-belted tires". 2. Characteristics: The arrangement of the cord fabric in radial tires differs from that in bias tires. In radial tires, the cords are not arranged in a crisscross pattern but are nearly parallel to the cross-section of the outer tire, resembling the arrangement of the Earth's meridians. The cord angle is small, generally 0°, and there are no intersecting points between the cords of the tire body. When the tire is in motion, the stress around the crown increases, causing axial extension and radial cracking of the tire body.
As a veteran mechanic with over 20 years of experience, radial tires essentially have their cord plies arranged like the meridians on a globe, running vertically from one bead to another. This design makes the tire's contact patch particularly soft, providing stable grip and fuel efficiency. If you squat down and pinch the sidewall, you'll notice it's thin and flexible, right? The advantage is better shock absorption for a comfortable ride, but the downside is that a scratch on the side can easily lead to bulging or a blowout. The biggest difference between radial and bias-ply tires lies in their internal skeleton arrangement—the 'R' marking on the tire sidewall indicates the radial structure. Nowadays, over 90% of passenger vehicles use radial tires because they're quieter, more durable, but you do need to be careful when going over potholes.
