KNOW YOUR TIRE

KNOW YOUR TIRE

A.BASICS

What is a Tire?

A tire is a ring-shaped container that have air. It surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface travelled over. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, which also provide a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint that is designed to match the weight of the vehicle with the bearing strength of the surface that it rolls over by providing a bearing pressure that will not deform the surface excessively.
A Tire is an integral component of a vehicle suspension system and is the intermediary between the vehicle and the road. A very important fact that is always forgotten is that the vehicle is carried by the air within the tire and not by the tire itself. This is why it is extremely important to maintain the required pressure to lift the vehicle and to maximize the performance of the tire.

TIRES CLASSIFICATION:

B. CLASSIFICATION

There is different classification for tires such as:

1)Based on Construction and their components.

A.Bias Tire

Bias tire is distinguished by the construction of their inner plies. A tire ply is a layer inside the tire that can be constructed of various materials including rubber, steel, nylon, and fiberglass. The plies may also consist of a combination of these materials.

B.Belted Bias Tire

A belted bias tire starts with two or more bias-plies to which stabilizer belts are bonded directly beneath the tread. This construction provides smoother ride that is like the bias tire, while lessening rolling resistance because the belts increase tread stiffness.

C.Radial Tire

Radial tires have body cords that run parallel from bead to bead at a 90° angle to the direction of rotation of the tire. Most medium and heavy truck tires have single steel cord body plies. Light truck, medium, and heavy radial truck tires frequently have up to four belts. The outer belt on truck tires with four belts is often referred to as protector ply placed on the tire to prevent cuts and rust from damaging the inner structural belts. The protector ply is often a large, thicker cable than the underlying working belts and body plies.

D.Solid

Many tires used in industrial and commercial applications are non-pneumatic, and are manufactured from solid rubber and plastic compounds by molding process. Solid tires include those used for lawn mowers, skateboards, golf carts, scooters, and many types of light industrial vehicles, carts, and trailers. One of the most common applications for solid tires is for material handling equipment (forklifts). Such tires are installed by means of a hydraulic tire press.

E.Airless

Airless tires are tires that are not supported by air pressure. They are used on some small vehicles such as riding lawn mowers and motorized golf carts. They are also used on heavy equipment such as backhoes, which are required to operate on sites such as building demolition, where risk of tire punctures is high. Tires composed of closed-cell polyurethane foam are also made for bicycles and wheelchairs.

2)Based on Carcass Materials.

  • a)Nylon
  • b)Steel Belted
  • c)All Steel
  • d)Polyester Belted
  • e)Rayons
  • f)Other’s

3)Based on Application.

  • a)Light Truck
  • b)Truck/Bus
  • c)Passenger Car
  • d)2/3 Wheelers
  • e)Agricultural
  • f)Off the road
  • g)Aero
  • h)Speciality
  • i)Bicycle

4)Based on Pattern Design.

  • Lug
  • Rib
  • Semi Lug

APPLICATIONS

Tires are classified into several standard types, based on the type of vehicle they serve. Since the manufacturing process, raw materials, and equipment vary according to the tire type, it is common for tire factories to specialize in one or more tire types. In most markets, factories that manufacture passenger and light truck radial tires are separate and distinct from those that make aircraft or off-the-road (OTR) tires.

1.Passenger Vehicles and Light Truck:

All Season Tires

All-season tires are designed with rubber that will stay flexible in both warm and cold weather. The tread is also designed to give stability in snow and push away water, which helps allow all-season tires to provide adequate handling in various weather conditions.

All Terrain Tires

An all-terrain tire is a type of automotive tire most commonly found on four-wheel-drive vehicles. The all-terrain tire is intended to provide a good compromise between off-road capability and on-road manners.

Low Profile Tires

A low-profile tire is one with a shorter sidewall than a traditional tire and a wider tread. When you look at it directly from the side, the distance between the rim and the tread is shorter. Manufacturers express the profile of a tire as its "aspect ratio," which is shown as part of the code on the sidewall of the tire.

Mud Tires

Mud tires are a type of auto tire that are used especially for traversing muddy surfaces. Sometimes called mud-terrain tires, these tires are made with special features to enhance their treading capabilities.

Performance Tires

Performance tires are typically low-profile tires with large tread blocks for dry traction and grip. They are usually found on sports cars and sport sedans because they are designed to handle higher speeds and corner well.

Snow / Winter Tires

Snow tires also called winter tires are tires designed for use on snow and ice. Snow tires have a tread design with bigger gaps than those on summer tires, increasing traction on snow and ice.
Snow tires feature a large amount of sipes, which helps the tread bite through snow. They are also constructed of soft rubber that won’t harden when temperatures drop, leading to better traction in snow and rain.

Light Trailer tires

Light trailer is use on public highways often have different tires than those seen on cars. Often they are bias ply rather than radial tires, and they often don't have as aggressive a tread pattern as standard road tires. They are not built for high traction in most cases, because in most cases it is not vital that trailer tires have as good a traction as that of the vehicle towing the trailer.

Run Flat Tires

Several innovative designs have been introduced that permit tires to run safely with no air for a limited range at a limited speed. These tires typically feature strong, load-supporting sidewalls. Another approach is an auxiliary support structure fixed to the rim inside the pneumatic tire that will bear the load in the event of a deflation.

A disadvantage is that many run-flat tires cannot be repaired if a puncture occurs. This is due to manufacturer's informing the automotive industry that the state in which the sidewall is in cannot be determined due to the compacted sidewall of rubber. Some brands may permit one repair to a run flat tire, while others do not allow any.

Spare

Some vehicles carry a spare tire, already mounted on a wheel, to be used in the event of flat tire or blowout. Mini spare, or "space-saver spare" tires are smaller than normal tires to save on trunk/boot space, gas mileage, weight, and cost. Mini spares have a short life expectancy and a low speed rating, often below 60 miles per hour (97 km/h).

2.Heavy Duty Trucks:

Heavy duty tires are also referred to as Truck/Bus tires. These are the tire sizes used on vehicles such as commercial freight trucks, dump trucks, and passenger buses. Truck tires are sub-categorized into specialties according to vehicle position such as steering, drive axle, and trailer. Each type is designed with the reinforcements, material compounds, and tread patterns that best optimize the tire performance. A relatively new concept is the use of "Super Singles" or Wide Singles. Generally in a dual configuration, there are 2 tires per position, each between 275 mm-295 mm wide. The Super Single replaces these with a single tire, usually 455 mm wide. This allows for less tread to be contacting the ground and also eliminates 2 sidewalls per position. Along with the weight savings of about 91 kilograms (200 lb) per axle, this enables vehicles using these to improve fuel economy.

3.Off the Road:

Off-the-road (OTR) tires include all tires not running on the common asphalt roads, such as fitted on construction vehicles (wheel loaders, backhoes, graders, trenchers), on airplanes, on mining vehicles, on forestry machinery. OTR tires can be of either bias or radial construction although the industry is trending toward increasing use of radial. Bias OTR tires are built with a large number of reinforcing plies to withstand severe service conditions and high loads.

Agricultural and Off-the Road Flotation Tires

The agricultural tire classification includes tires used on farm vehicles, typically tractors and specialty vehicles like harvesters. Driven wheels have very deep, widely spaced lugs to allow the tire to grip soil easily.
For off-road driving in a passenger vehicle, such as in mud, sand, or deep snow, high flotation tires are typically used. Flotation tires are not the same as M+S tires, as they are designed for low speeds and full-time off-road use rather than muddy and snow-covered roads. Flotation tires also help traction in swampy environments and where soil compaction is a concern, featuring large footprints at low inflation pressures to spread out the area where the rubber meets the ground. Knobby tires are particularly useful where the ground consists of loose particles that can be displaced by the knobs. Although the low pressure improves traction in many types of terrain, adjustments may need to be made for hard surfaces like paved and unpaved roads. Vehicles that use flotation tires for rock climbing are susceptible to flat tires in which the tire pops off the rim, breaking the "bead."

5.Racing

Racing tires are highly specialized according to vehicle and race track conditions. This classification includes tires for drag racing, Auto-x, drifting, Time Attack, Road Racing  – as well as the large-market race tires for Formula One, IndyCar, NASCAR, V8 Supercars, WRC, MotoGP and the like. Tires are specially engineered for specific race tracks according to surface conditions, cornering loads, and track temperature. Racing tires often are engineered to minimum weight targets, so tires for a 500-mile (800 km) race may run only 100 miles (160 km) before a tire change. Some tire makers invest heavily in race tire development as part of the company's marketing strategy and a means of advertising to attract customers. Racing tires used on tarmac stages are called slick. When the road is wet a driver will use intermediary slicks and when the road is dry the soft slicks are used. Racing tires often are not legal for normal highway use.

6.Industrial

The Industrial tire classification is a bit of a catch-all category and includes pneumatic and non-pneumatic tires for specialty industrial and construction equipment such as skid loaders and fork lift trucks.

7.Bicycle

This classification includes all forms of bicycle tires, including road racing tires, mountain bike tires, snow tires, and tubular tires, used also with other human-powered vehicles.

8.Aircraft

Aircraft tires are designed to withstand extremely heavy loads for short durations. The number of tires required for aircraft increases with the weight of the aircraft (because the weight of the airplane has to be distributed better). Aircraft tire tread patterns are designed to facilitate stability in high crosswind conditions, to channel water away to prevent hydroplaning, and for braking effect.

9.Motorcycle

Motorcycle tires are the outer part of motorcycle wheels, attached to the rims, providing traction, resisting wear, absorbing surface irregularities, and allowing the motorcycle to turn via counter steering. The two Tires' contact patches are the motorcycle's connection to the ground, and so are fundamental to the motorcycle's suspension behaviour, and critically affect safety, braking, fuel economy, noise, and rider comfort.

TIRE NUMBER

205 = Tire width

The width of your Tire, in millimetres, measured from sidewall to sidewall.

55 = Aspect ratio

This is the ratio of the Tire’s cross-section to its width, expressed as a percentage. An aspect ratio of 65, for example, indicates that the Tire’s height is 65% of its width.

16 = Wheel diameter

The diameter (height) of the wheel in inches.

91 = Load index

Your Tire’s load index relates to its maximum carrying capacity (in kg). You’ll find the load rating of your Tire on the sidewall, just to the right of the diameter.

For example, a Tire with a load index of 91 can carry 615kg of weight.

Load ratings and speed ratings should be looked at together when you buy a new Tire. Also remember to check your manufacturer’s recommendations.

W = Speed rating

The speed rating is the maximum speed for a Tire when it is correctly inflated and being used under load. The speed rating is the letter at the end of the sidewall, after the load index number. A Tire with a speed rating of V, for example, has a maximum speed of 240 km/h.

When buying new Tires, make sure you match their speed rating with the speed capabilities of your vehicle.