1、 What is a meridian

In order to determine people's respective positions on Earth, scientists, like cutting watermelons, divide the Earth into 360 equal parts centered around the South and North Poles. The longitude line from the North Pole to the South Pole on the Earth's surface passing through the Greenwich Observatory in London, UK, is called the 0 degree longitude line. The bisector east of Greenwich is called the east longitude, and the bisector west is called the west longitude. At the same time, based on the equator, the Earth is divided into 90 equal coils parallel to the equatorial circle, each in the north and south, called latitude lines. The 0 degree meridian passing through the Greenwich Observatory is called the prime meridian, while other meridians are commonly referred to as meridians.

2、 What is a radial tire

The tire body cord and buffer layer cord of bias ply tires are composed of multiple layers of adhesive cord fabric, and the number of layers of tire body cord and buffer layer varies among different types of tires. But these cords are arranged diagonally and crosswise, meaning that the odd numbered layers are in one direction and the even numbered layers are in the opposite direction.

As shown, the tire is composed of six main components: the tire crown, sidewall, and belt layer (generally referred to as the buffer layer for diagonal tires, and the belt layer for radial tires, hereinafter collectively referred to as the belt layer), as well as the tire body, tire bead, and inner liner (or airtight layer).

The arrangement direction of the tire body cord of a radial tire is similar to the Earth meridian, with the wheel axle as the center, from one tire bead to another, arranged in a longitudinal direction. Although the belted cord is also arranged diagonally and crosswise, it is at a small angle (usually between 15 ° and 25 °) to the centerline of the tire crown.

So what is a radial tire? Definition: This type of tire is called a radial tire, where the tire body cords are arranged in the radial direction (at or near 90 ° to the centerline of the tire crown) and the cords are arranged almost in a circumferential direction with a belt layer that tightens the tire body. This is also the fundamental difference between radial tires and diagonal tires.