Tire pressure monitoring system

Some actually measure the air pressure and some make indirect measurements, such as gauging when the relative size of the tire changes due to lower air pressure. These systems are becoming mandatory in countries such as the United States. Tire pressure monitoring systems are electronic systems that continuously monitor tire pressure on a vehicle, and alarm when the pressure goes below a warning limit. There are several types of designs to monitor tire pressure. Tires are specified by the manufacturer with a maximum load rating. Loads exceeding the rating can result in unsafe conditions that can lead to steering instability and even rupture.

Tread

The tread is that portion of the tire that comes in contact with the road. The tread is a thick rubber compound formulated to provide a high level of traction that does not wear away too quickly.

Treads are often designed to meet specific product marketing positions. High performance tires have small void ratios to provide more rubber in contact with the road for higher traction, but may be compounded with softer rubber that provides better traction, but wears quickly.

Voids are spaces between lugs that allow the lugs to flex. Tread patterns feature non-symmetrical lug sizes circumferentially in order to minimize noise.

Mud and snow tires are designed with higher void ratios to channel away rain and mud, while providing better gripping performance. When installing new tires, you should try and replace all four at once. Installing just two new tires on the front or rear will encourage under steer or over steer, depending on the vehicle and position of the new tires.

The tread pattern is characterized by the geometrical shape of the grooves, lugs, and voids. Grooves run circumferentially around the tire, and are needed to channel away water. Lugs are that portion of the tread design that contacts the road surface.

• • 2.1 Tread
  • 2.2 Tread lug
  • 2.3 Tread void
  • 2.4 Rain groove
  • 2.5 Sipe
  • 2.6 Wear bar
  • 2.7 Contact patch
  • 2.8 Bead
  • 2.9 Sidewall
  • 2.10 Shoulder
  • 2.11 Inner tube
  • 2.12 Wheel
  • 2.13 Valve stem
  • 2.14 Tire pressure monitoring system
  • 2.15 Load rating
  • 2.16 Inflation pressure
  • 2.17 Speed rating
  • 2.18 Rotation
  • 2.19 Wheel alignment
  • 2.20 Retread
  • 2.21 Flat
  • 2.22 Hydroplaning (or aquaplaning)
• 3 Markings
  • 3.1 DOT Code
  • 3.2 E-mark
  • 3.3 Mold serial number
  • 3.4 Codes
• 4 Use classifications
  • 4.1 Passenger and light truck types
    • 4.1.1 High Performance
    • 4.1.2 Mud and Snow
    • 4.1.3 All Season
    • 4.1.4 All-terrain
    • 4.1.5 Spare
    • 4.1.6 Run-flat
  • 4.2 Heavy duty truck
  • 4.3 Off-the-road (OTR)
  • 4.4 Agricultural
  • 4.5 Racing
  • 4.6 Industrial
  • 4.7 Bicycle
  • 4.8 Aircraft
  • 4.9 Motorcycle
• 5 Construction types
  • 5.1 Bias
  • 5.2 Belted bias
  • 5.3 Radial
  • 5.4 Solid
  • 5.5 Semi-pneumatic
• 6 Performance metrics
  • 6.1 Tread wear
  • 6.2 Dry traction
  • 6.3 Wet traction
  • 6.4 Force variation
  • 6.5 Balance
  • 6.6 Centrifugal growth
  • 6.7 Rolling resistance
  • 6.8 Stopping distance
  • 6.9 TKPH

Tire Industry

The earliest tires were bands of iron (later steel), placed on wooden wheels, used on carts and wagons. The tire would be heated in a forge fire, placed over the wheel and quenched, causing the metal to contract and fit tightly on the wheel. The tension of the metal band served the purpose of holding or "tying" the wooden spokes of the wheel together, hence the term "tire." In addition to tying the spokes together, the tire also provided a wear-resistant surface to the perimeter of the wheel. As wheels changed over time, the term "tire" continued to be used for the outer band even when it no longer served the purpose of tying the spokes together.
The first practical pneumatic tire was made by the Scot John Boyd Dunlop for his son's bicycle, in an effort to prevent the headaches his son had while riding on rough roads (Dunlop's patent was later declared invalid because of prior art by fellow Scot Robert William Thomson).
A skilled craftsman, known as a wheelwright, did this work. The tension of the metal band served the purpose of holding or "tying" the wooden spokes of the wheel together, hence the term "tire."