18-01-2013, 10:32 AM
NEW AGE TYRES
NEW AGE.doc (Size: 185 KB / Downloads: 98)
INTRODUCTION
Everybody knows what a tyre is, but not many know why tyres come in all different sizes. Explaining all of the variations makes the subject very technical and complicated. Here we endeavour to simplify some of the concepts and technical jargon.
Soon after man invented the wheel he realised that it wore out as he used it. A piece of material was then wrapped around the outside of the wheel either to rebuild it or prevent it from wearing out. This material wrapped around the outside of the wheel became known as a “tyre”.
In our modern world there are two types of tyres: solid and pneumatic:
Solid tyres were the original type of tyre used. As the name suggests they are made up of some type of solid material that is wrapped around the wheel. There are many different types of solid tyres, which will be explained later.
Pneumatic tyres have air pressure inside the tyre. The pneumatic tyre must be fitted to the outside of the wheel and inflated with air pressure. There are three types of pneumatic tyres: bias ply, bias belted and radial ply.
There is one simple difference between the solid tyre and the pneumatic tyre: A solid tyre pushes into the road surface and the pneumatic tyre sits on top of the road surface.
Say you are pushing a wheel barrow load of bricks over the lawn. If the wheel barrow had a solid wheel it would dig a rut into the lawn and get stuck, and it would be difficult to push. A wheelbarrow with a pneumatic tyre would roll over the lawn, leaving a small wheel mark, and it would be easy to push. In other words, the solid tyre digs into the soft lawn surface and the pneumatic tyre “floats” over the soft lawn surface.
What happens if you push the wheelbarrows over a hard concrete footpath? You would find that it is easier to push the wheelbarrow with the solid wheel than the one with the soft pneumatic tyre. This is because the solid wheel sits on top of the hard concrete surface and rolls easily, while the pneumatic tyre squashes out and deforms over the surface making it harder to push. The more air pressure you put into the pneumatic tyre the easier it is to push over the concrete foot-path.
The pneumatic tyre is very sensitive to the air pressure inside the tyre where the solid tyre is very sensitive to surface it is running on – this is the primary difference between solid and pneumatic tyres.
Different Types of Solid Tyres
The first difference in solid tyres is the type of material that the solid tyre is made from. The material could be steel, rubber, wood, leather or some type of man-made plastic material.
The second difference is the type of solid tyre - how it is made. Some are completely solid, others are hollow inside, some are filled with foam and some are pressurised inside. There are many other variations with springs and layered materials inside.
Different Types of Pneumatic Tyres
All pneumatic tyres are made of rubber reinforced with tyre cord. The three different types of pneumatic tyres - bias, bias-belted and radial - explain the different ways in which the tyre cord is place inside the tyre. Solid tyres do not have tyre cord inside to hold the air pressure.
In simple terms, a pneumatic tyre is made up of rubber just like a party balloon. The rubber party balloon is blown up with air pressure. The more air you put inside it the balloon gets bigger and bigger.
A rubber tyre is the same except tyre cord is put inside the rubber balloon to hold its shape against the increasing air pressure. The way in which this tyre cord is placed inside the tyre determines its type.
Solid tyres differ from pneumatic tyres as pneumatic tyres need air pressure inside them to work. The tyre cord inside them holds the tyre’s shape and determines what type of pneumatic tyre it is.
HISTORY
A series of plies of cord reinforces a tire. Without this, a tire would be flexible and weak. The network of cords that gives the tire strength and shape is called the carcass. Since the 1960s, all common tires have a carcass of cords of polyester, steel, or other textile materials, inlaid with several layers of rubber.
In the past, the fabric was built up on a flat steel drum, with the cords at angles of about +60 and −60 degrees from the direction of travel, so they criss-crossed over each other. They were called cross-ply or bias ply tires. The plies were turned up around the steel wire beads and the combined tread/sidewall applied. The green (uncured) tire was loaded over a curing bladder and shaped into the mold. This shaping process caused the cords in the tire to assume an S shape from bead to bead. The angle under the tread stretched down to about 36 degrees. This was called the Crown Angle. In the sidewall region the angle was 45 degrees and in the bead it remained at 60 degrees. The low crown angle gave rigidity to support the tread and the high sidewall angle gave comfort.
Rubber tires
The first practical pneumatic tire was made by John Boyd Dunlop while working as a
veterinarian in May Street, Belfast, in 1887 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). Dunlop is credited with "realizing rubber could withstand the wear and tear of being a tire while retaining its resilience".
Pneumatic tires are made of a flexible elastomer material, such as rubber, with reinforcing materials such as fabric and wire. Tire companies were first started in the early 20th century, and grew in tandem with the auto industry. Today, over 1 billion tires are produced annually, in over 400 tire factories, with the three top tire makers commanding a 60% global market share.
TYPES OF TYRES
Who knew that an early wheel found some 5500 years back in Mesopotamia would become one of the most wanted and useful accessories in the modern age! But it was only in 1844 that Charles Goodyear discovered the vulcanization process and introduced tyres to the world of automobiles. Today, about 85% of the car’s weight is supported by air provided by the vulcanized rubber, while the remaining 15% is supported by the tyre. Thus, you can imagine what a car would look like without the presence of a tyre. What legs are to us, tyres are to vehicles! However, there are certain criteria for choosing a tyre for your car since each has its own specifications and characteristics. Your choice would depend on what you use your car for, where you reside, how rough or smooth you drive, and several other factors. Considering the different driving conditions, given here are some kinds of tyres that are most commonly used. Take a look at them.
Different Kinds of Tyres
Standard Tyres
Standard tyres are probably the ones on which every production car comes out of the factory. They are suitable for all weather conditions since they have a pattern that allows them to run smoothly all year round. Hence, they are also known as all-round or all-season tyres. They are designed to provide a perfect balance between grip, performance, longevity, noise, and wet-weather safety. Further, they are made with a harder rubber compound that sacrifices outright grip and cornering performance in order to increase the life of the tyres. Hence, they work well in wet as well as dry conditions.
Performance Tyres
Designed especially for withstanding the dry season, performance tyres are preferred for faster cars or by people who love to drive harder and rougher than average riders. Designed with a softer rubber compound, performance tyres deliver excellent grip performance, though it reduces the lifespan of the tyre. Nonetheless, they are best suited for dry regions and can be used throughout the year if you reside in places with warm climatic conditions and little rain. This is why they are also referred to as summer tyres.
Winter Tyres
Also known as wet-weather tyres, winter tyres are designed to help people drive through bad weather brought by winters or rainfalls. They are made of hard rubber compound that heats up quickly both in wet and cold conditions, thereby providing excellent grip on challenging and risky roads. They are even equipped with small metal studs embedded into the tread that makes driving through ice and snow smooth and easy. However, they cannot be used round the year since the tyres wear out quickly in dry conditions damaging the road surface as well.
All-Terrain Tyres
Designed for SUVs and light trucks, all-terrain tyres are large in size with stiffer sidewalls and bigger tread block patterns. Though these larger tread blocks create a lot of noise on normal roads, they are very efficient on loose sand and dirty off-road by having a good grip on them. The rubber compound used in all-terrain tyres is generally middle-of-the-road, which is neither soft nor hard. These provide a perfect balance between off-road capabilities and good on-road manners.
Mud Tyres
Mud tyres are the best option for driving across muddy roads due to the presence of massive and super-chunky tread blocks. The tread blocks are designed to provide excellent hold on muddy surfaces, thereby allowing the driver to drive through with ease and convenience. However, mud tyres do not offer any advantages of driving on any other road condition. Nonetheless, when it comes to off-road driving, they are simply unmatchable.
Run Flat Tyres
With the changes and developments in the car industry, tyres, too, have got a new face. Run flat tyres are the newest and most accepted concept on new cars. They are intended to reduce the loss of handling a car while your tyre gets punctured. As such, you can continue driving your car without letting air enter the tyre, but this is only possible for short distances at low speeds.
Construction
With only radial cords, a radial tire would not be sufficiently rigid at the contact with the ground. To add further stiffness, the entire tire is surrounded by additional belts that are oriented along the direction of travel. These belts can be made of steel (hence the term steel-belted radial), Polyester, or Aramid fibers such as Twaron and Kevlar.
In this way, low radial tires separate the tire carcass into two separate systems:
The radial cords in the sidewall allow it to act like a spring, giving flexibility and ride comfort
Construction types
Bias tire (or cross ply) construction utilizes body ply cords that extend diagonally from bead to bead, usually at angles in the range of 30 to 40 degrees, with successive plies laid at opposing angles forming a crisscross pattern to which the tread is applied. The design allows the entire tire body to flex easily, providing the main advantage of this construction, a smooth ride on rough surfaces. This cushioning characteristic also causes the major disadvantages of a bias tire: increased rolling resistance and less control and traction at higher speeds.
NEW AGE.doc (Size: 185 KB / Downloads: 98)
INTRODUCTION
Everybody knows what a tyre is, but not many know why tyres come in all different sizes. Explaining all of the variations makes the subject very technical and complicated. Here we endeavour to simplify some of the concepts and technical jargon.
Soon after man invented the wheel he realised that it wore out as he used it. A piece of material was then wrapped around the outside of the wheel either to rebuild it or prevent it from wearing out. This material wrapped around the outside of the wheel became known as a “tyre”.
In our modern world there are two types of tyres: solid and pneumatic:
Solid tyres were the original type of tyre used. As the name suggests they are made up of some type of solid material that is wrapped around the wheel. There are many different types of solid tyres, which will be explained later.
Pneumatic tyres have air pressure inside the tyre. The pneumatic tyre must be fitted to the outside of the wheel and inflated with air pressure. There are three types of pneumatic tyres: bias ply, bias belted and radial ply.
There is one simple difference between the solid tyre and the pneumatic tyre: A solid tyre pushes into the road surface and the pneumatic tyre sits on top of the road surface.
Say you are pushing a wheel barrow load of bricks over the lawn. If the wheel barrow had a solid wheel it would dig a rut into the lawn and get stuck, and it would be difficult to push. A wheelbarrow with a pneumatic tyre would roll over the lawn, leaving a small wheel mark, and it would be easy to push. In other words, the solid tyre digs into the soft lawn surface and the pneumatic tyre “floats” over the soft lawn surface.
What happens if you push the wheelbarrows over a hard concrete footpath? You would find that it is easier to push the wheelbarrow with the solid wheel than the one with the soft pneumatic tyre. This is because the solid wheel sits on top of the hard concrete surface and rolls easily, while the pneumatic tyre squashes out and deforms over the surface making it harder to push. The more air pressure you put into the pneumatic tyre the easier it is to push over the concrete foot-path.
The pneumatic tyre is very sensitive to the air pressure inside the tyre where the solid tyre is very sensitive to surface it is running on – this is the primary difference between solid and pneumatic tyres.
Different Types of Solid Tyres
The first difference in solid tyres is the type of material that the solid tyre is made from. The material could be steel, rubber, wood, leather or some type of man-made plastic material.
The second difference is the type of solid tyre - how it is made. Some are completely solid, others are hollow inside, some are filled with foam and some are pressurised inside. There are many other variations with springs and layered materials inside.
Different Types of Pneumatic Tyres
All pneumatic tyres are made of rubber reinforced with tyre cord. The three different types of pneumatic tyres - bias, bias-belted and radial - explain the different ways in which the tyre cord is place inside the tyre. Solid tyres do not have tyre cord inside to hold the air pressure.
In simple terms, a pneumatic tyre is made up of rubber just like a party balloon. The rubber party balloon is blown up with air pressure. The more air you put inside it the balloon gets bigger and bigger.
A rubber tyre is the same except tyre cord is put inside the rubber balloon to hold its shape against the increasing air pressure. The way in which this tyre cord is placed inside the tyre determines its type.
Solid tyres differ from pneumatic tyres as pneumatic tyres need air pressure inside them to work. The tyre cord inside them holds the tyre’s shape and determines what type of pneumatic tyre it is.
HISTORY
A series of plies of cord reinforces a tire. Without this, a tire would be flexible and weak. The network of cords that gives the tire strength and shape is called the carcass. Since the 1960s, all common tires have a carcass of cords of polyester, steel, or other textile materials, inlaid with several layers of rubber.
In the past, the fabric was built up on a flat steel drum, with the cords at angles of about +60 and −60 degrees from the direction of travel, so they criss-crossed over each other. They were called cross-ply or bias ply tires. The plies were turned up around the steel wire beads and the combined tread/sidewall applied. The green (uncured) tire was loaded over a curing bladder and shaped into the mold. This shaping process caused the cords in the tire to assume an S shape from bead to bead. The angle under the tread stretched down to about 36 degrees. This was called the Crown Angle. In the sidewall region the angle was 45 degrees and in the bead it remained at 60 degrees. The low crown angle gave rigidity to support the tread and the high sidewall angle gave comfort.
Rubber tires
The first practical pneumatic tire was made by John Boyd Dunlop while working as a
veterinarian in May Street, Belfast, in 1887 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). Dunlop is credited with "realizing rubber could withstand the wear and tear of being a tire while retaining its resilience".
Pneumatic tires are made of a flexible elastomer material, such as rubber, with reinforcing materials such as fabric and wire. Tire companies were first started in the early 20th century, and grew in tandem with the auto industry. Today, over 1 billion tires are produced annually, in over 400 tire factories, with the three top tire makers commanding a 60% global market share.
TYPES OF TYRES
Who knew that an early wheel found some 5500 years back in Mesopotamia would become one of the most wanted and useful accessories in the modern age! But it was only in 1844 that Charles Goodyear discovered the vulcanization process and introduced tyres to the world of automobiles. Today, about 85% of the car’s weight is supported by air provided by the vulcanized rubber, while the remaining 15% is supported by the tyre. Thus, you can imagine what a car would look like without the presence of a tyre. What legs are to us, tyres are to vehicles! However, there are certain criteria for choosing a tyre for your car since each has its own specifications and characteristics. Your choice would depend on what you use your car for, where you reside, how rough or smooth you drive, and several other factors. Considering the different driving conditions, given here are some kinds of tyres that are most commonly used. Take a look at them.
Different Kinds of Tyres
Standard Tyres
Standard tyres are probably the ones on which every production car comes out of the factory. They are suitable for all weather conditions since they have a pattern that allows them to run smoothly all year round. Hence, they are also known as all-round or all-season tyres. They are designed to provide a perfect balance between grip, performance, longevity, noise, and wet-weather safety. Further, they are made with a harder rubber compound that sacrifices outright grip and cornering performance in order to increase the life of the tyres. Hence, they work well in wet as well as dry conditions.
Performance Tyres
Designed especially for withstanding the dry season, performance tyres are preferred for faster cars or by people who love to drive harder and rougher than average riders. Designed with a softer rubber compound, performance tyres deliver excellent grip performance, though it reduces the lifespan of the tyre. Nonetheless, they are best suited for dry regions and can be used throughout the year if you reside in places with warm climatic conditions and little rain. This is why they are also referred to as summer tyres.
Winter Tyres
Also known as wet-weather tyres, winter tyres are designed to help people drive through bad weather brought by winters or rainfalls. They are made of hard rubber compound that heats up quickly both in wet and cold conditions, thereby providing excellent grip on challenging and risky roads. They are even equipped with small metal studs embedded into the tread that makes driving through ice and snow smooth and easy. However, they cannot be used round the year since the tyres wear out quickly in dry conditions damaging the road surface as well.
All-Terrain Tyres
Designed for SUVs and light trucks, all-terrain tyres are large in size with stiffer sidewalls and bigger tread block patterns. Though these larger tread blocks create a lot of noise on normal roads, they are very efficient on loose sand and dirty off-road by having a good grip on them. The rubber compound used in all-terrain tyres is generally middle-of-the-road, which is neither soft nor hard. These provide a perfect balance between off-road capabilities and good on-road manners.
Mud Tyres
Mud tyres are the best option for driving across muddy roads due to the presence of massive and super-chunky tread blocks. The tread blocks are designed to provide excellent hold on muddy surfaces, thereby allowing the driver to drive through with ease and convenience. However, mud tyres do not offer any advantages of driving on any other road condition. Nonetheless, when it comes to off-road driving, they are simply unmatchable.
Run Flat Tyres
With the changes and developments in the car industry, tyres, too, have got a new face. Run flat tyres are the newest and most accepted concept on new cars. They are intended to reduce the loss of handling a car while your tyre gets punctured. As such, you can continue driving your car without letting air enter the tyre, but this is only possible for short distances at low speeds.
Construction
With only radial cords, a radial tire would not be sufficiently rigid at the contact with the ground. To add further stiffness, the entire tire is surrounded by additional belts that are oriented along the direction of travel. These belts can be made of steel (hence the term steel-belted radial), Polyester, or Aramid fibers such as Twaron and Kevlar.
In this way, low radial tires separate the tire carcass into two separate systems:
The radial cords in the sidewall allow it to act like a spring, giving flexibility and ride comfort
Construction types
Bias tire (or cross ply) construction utilizes body ply cords that extend diagonally from bead to bead, usually at angles in the range of 30 to 40 degrees, with successive plies laid at opposing angles forming a crisscross pattern to which the tread is applied. The design allows the entire tire body to flex easily, providing the main advantage of this construction, a smooth ride on rough surfaces. This cushioning characteristic also causes the major disadvantages of a bias tire: increased rolling resistance and less control and traction at higher speeds.