Tire

A tire is a rubber, either solid or inflated, item that surrounds a wheel in order to improve the function. They assist in traction, steering, and braking.

Table of Contents

• 1. Parts
  • 1.1 Tread
  • 1.2 Bead
  • 1.3 Sidewall
  • 1.4 Casing
  • 1.5 Valve
• 2. Tire Codes

Parts

Tread

The tread is the part of the tire that makes contact with the road. The tread pattern helps the tire grip the road. It is subject to wear and tear under normal usage.

Bead

The bead is the part of the tire that makes contact with the wheel rim. It is reinforced by a steel wire. It creates a seal to hold air in a tubeless tire.

Sidewall

The sidewall is the part between the tread and bead. It usually contains the tire codes and manufacturer's name.

Casing

The casing is the part underneath the tread and sidewall that keeps the structure of the tire when inflated.

Valve

The valve lets air in and out of the tire.

Tire Codes

Tires have an alphanumeric code that describes various attributes of the tire such as vehicle type, diameter of the wheel, and tire section width(measured across the tread in millimeters).

An example of a tire code is P245/50ZR-16.

P is Passenger

245 is the tire section width (245mm).

50 is the aspect ratio(the sidewall height is 50% of its width).

Z is the speed rating(149+mph).

R is the tire type (radial).

16 is the diameter of the wheel.