Report of Wheels and Tyres

8/3/2019 Report of Wheels and Tyres

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Wheels and Tyres

1. Wheels..1

2. Tyres.....4

3. Required dimension in tyre..8

4. Function of tyre9

5. Raw material11

6. Bias tyre...12

7. Advantages and Disadvantages of bias tyre.14

8. Radial Ply tyre..15

9. Advantages and Disadvantages of Radial tyre.17

10. Difference between bias and radial tyre..18

11. Sidewall Information..19

12. Load Index chart.22

13. Wheels and Tyres suitable for MUCS.24

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Wheels:

A wheel is a circular device that is capable of rotating on an axle through its

centre, facilitating movement or transportation while supporting a load

(mass), or performing labour in machines.

Bolt Pattern:

Pitch circle diameter or P.C.D. is the same term as bolt pattern; it can be

measured in mm or inches. PCD can be found on any wheel by measuring

from the center of the wheel to the center of the wheel hole and multiplying

by two. Or, by measuring across two bolt holes from the center of the bolt

hole to the center of the other bolt hole.

If you were to see an advertisement for wheels that reads; 5 X 4.75 this

would mean the following:

The wheels had 5 - five studs or holes

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Offset:

The offset of a wheel is the distance from its hub mounting surface to the

centerline of the wheel. The offset can be one of three types (measured in

millimeters).

Zero Offset:The hub mounting surface is even with the centerline of the wheel.

Positive:

The hub mounting surface is toward the front or wheel side of the wheel.

Positive offset wheels are generally found on front wheel drive cars and

newer rear drive cars.

Negative:

The hub mounting surface is toward the back or brake side of the wheels

centerline. "Deep dish" wheels are typically a negative offset.

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Pitch Circle Diameter:The Pitch Circle Diameter is the diameter of the circumference of the center

line of the lug nut holes; this can be four, five or six lug. The easiest way of

measuring four or six lug wheels is take the diagonal holes and measure

from the outer edge of one hole to the inner edge of the second hole. With

five lug wheels this is not possible as there are not diagonal holes, therefore

the simplified way would be to measure the outer circumference and inner

circumference of the holes. The difference should be divided by two and

added onto the smaller circumference or deducted from the larger

circumference. The BCD may be expressed in millimeters or inches, and is

usually given with the number of bolts. For example, a 1974 MG B has a

4/4.5 inch (4/114.3 mm) wheel hub, meaning it has a 4-bolt pattern with a

4.5 inch (114.3 mm) bolt circle.

The most common BCD values are 100 mm (3.94 inches) and 4.5 inches

(114.3 mm).

Determining the bolt circle:

For a 4- or 6-bolt wheel, this measurement is merely the distance between

the center of two diametrically opposite bolts. In the 4-bolt picture to the

right, this would be the distance between holes #1 and #4.

Some basic geometry is needed to find the center of a 5-bolt pattern. In

practice, the BCD can be found by multiplying the center distance between

any two adjacent holes by 1.701.

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Generally, the BCD b can be calculated for any wheel from the number of

bolts n and the center distance between two adjacent bolts das:

.

Centre Bore:

The center bore is the location hole machined in the center of the

wheel and this varies from one vehicle to another. It is essential the wheels

purchased have the correct center bore for the vehicle they are to suit,

otherwise you may experience balancing problems.

Tyre:It is a ring-shaped covering that fits around a wheel rim to protect it

and enable better vehicle performance by providing a flexible cushion that

absorbs shock while keeping the wheel in close contact with the ground.

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The tire is an assembly of numerous components that are built up on

a drum and then cured in a press under heat and pressure. Heat facilitates

polymerization reactions that cross links rubber monomers to create long

elastic molecules. These polymers create the elastic quality that permits the

tire to be compressed in the area where the tire contacts the road surface and

spring back to its original shape under high-frequency cycles. Typical

components used in tire assembly are listed below.

Bead:

The part of the tyre, which is of such shape and structure as to fit the

wheel rim and hold the tyre on it.

Carcass:

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That part of the pneumatic tyre structure other than the tread and

sidewall rubber, which, when inflated, bears the load.

Cord:

It means the strands or filaments of material forming the plies of the

tyre structure.

Inner liner:

The layer of rubber forming the inside surface of a tubeless tyre that

contains the inflating medium within the tyre.

Ply:

A layer of rubber-coated parallel cords.

Sidewall:

It means that portion of a tyre between the tread and the bead.

Tread:

It means that part of a tyre that comes into contact with the road.

Tread pattern:

The geometric arrangement of blocks, ribs and grooves of the tread.

Tread groove:

The space between two adjacent ribs or blocks in the tread pattern.

Principal grooves:

The wide grooves positioned in the central zone of the tyre tread,

which, in the case of car tyres, have the tread, wear indicators located in the

base.

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Secondary grooves:

The supplementary grooves of the tread pattern, which may disappear

in the course of the tyres life.

Regroovable:

A truck tyre designed with sufficient under tread material to allow

regrooving of the original tread pattern at some stage during the service life

of the tyre. Regrooving of car tyres and motorcycle tyres is prohibited.

Tread wear indicators (TWI):

The projections within the principal grooves designed to give a visual

indication of the degree of wear of the tread.

Required Dimensions in tyre:

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Section width:

The linear distance between the outsides of the sidewalls of an

inflated pneumatic tyre, excluding elevations due to labeling (marking),

decoration or protective bands or ribs;

Overall width:

The linear distance between the outsides of the sidewalls of an

inflated pneumatic tyre, including labeling (marking), decoration and

protective bands or ribs;

Section height:

A distance equal to half the difference between the outer diameter

of the tyre and the nominal rim diameter;

Nominal aspect ratio (Ra):

The centuple of the number obtained by dividing the number

expressing the section height by the number expressing the nominal section

width;

Outer diameter:

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The overall diameter of an inflated new pneumatic tyre;

Function of tyre:

Drivers often forget that tyres are the only point of contact of a

vehicle with the ground and, as a result, they must perform a certain number

of functions such as steering, carrying a load, cushioning, rolling,

transmitting drive, lasting a long time.

Steering:

Tyres should steer the vehicle with precision, irrespective of the state

of the surface and/or weather conditions. The stability of a vehicles path

depends on the tyre holding its course. A tyre must stand up to transversal

forces without drifting from its path. In general, each vehicle has a particular

inflation pressure for each axle. Respecting pressure variations betweenfront and rear tyres ensures ideal directional stability.

Carrying:

Tyres support the vehicle not only when it is moving but also when it

is standing still and must be able to resist considerable load transfers during

acceleration and braking. A car tyre carries more than 50 times its own

weight.

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Cushioning:

Tyres absorb the shocks due to obstacles, and cushions the vehicle

from other irregularities in the road, ensuring driver and passenger comfort

as well as the long life of the vehicle. .

The main characteristic of a tyre is its suppleness, particularly in a vertical

direction. The significant elasticity of the air contained in the tyre enables it

to take the impact of any deformations caused by obstacles and uneven

surfaces. The right pressure gives high levels of comfort whilst retaining

good steering capacity.

Rolling

A tyre rolls more evenly, more safely and with less resistance for

better driving pleasure

Transmittingdrive:

Tyres transmit drive: the engines usable power, braking effort. The

quality of these few square inches in contact with the ground dictates thelevel of transmission of drive.

Long-lasting:

The tyre lasts, or in other words, keeps its optimum performance

level for millions of wheel revolutions. The tyres wear depends on its

conditions of use (load, speed, condition of the road surface, state of the

vehicle, style of driving, etc.) but above all the quality of its contact with the

ground. Pressure therefore plays a major role.

Raw Material:

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Rubber is the main raw material used in manufacturing tires, and

both natural and synthetic rubber is used. Natural rubber is found as a milky

liquid in the bark of the rubber tree, Hevea Brasiliensis. To produce the raw

rubber used in tire manufacturing, the liquid latex is mixed with acids that

cause the rubber to solidify. Presses squeeze out excess water and form the

rubber into sheets, and then the sheets are dried in tall smokehouses, pressed

into enormous bales, and shipped to tire factories around the world.

Synthetic rubber is produced from the polymers found in crude oil.

The other primary ingredient in tire rubber is carbon black. Carbon black is a

fine, soft powder created when crude oil or natural gas is burned with a

limited amount of oxygen, causing incomplete combustion and creating a

large amount of fine soot. So much carbon black is required for

manufacturing tires that rail cars transport it and huge silos store the carbon

black at the tire factory until it is needed.

Sulfur and other chemicals are also used in tires. Specific chemicals, when

mixed with rubber and then heated, produce specific tire characteristics such

as high friction (but low mileage) for a racing tire or high mileage (but lower

friction) for a passenger car tire. Some chemicals keep the rubber flexible

while it is being shaped into a tire while other chemicals protect the rubber

from the ultraviolet radiation in sunshine.

Types of Tyres:

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There are two basic types of tyre construction:

Bias ply tyres

Radial ply tyres

Bias Ply tyres:

Bias ply tires are constructed of overlapping crossed layers of

cord material and are typically made with nylon, polyester, or other

materials. The crossed plies run on a diagonal from tire bead to tire bead and

comprise a generally stiff sidewall area. Sometimes, extra crossed plies or

breakers are used under the tread area to further stiffen the crown area and

provide better wear resistance or other performance parameters (such as

puncture resistance, etc.).

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Performance and Purpose of a Bias Ply:

Bias ply tires have a limited purpose in life and are only used for

specific purposes or jobs. The reason for this is because of its performance

characteristics. However for some jobs the bias ply tire is an idea tire for the

purpose such as for the tires of a towed trailer, farm equipment tires, some

purpose built tires like extreme terrain tires and some forms of racing still

use bias ply tires. The reasons for this limited use are:

The bias-ply tire casing is constructed to form one working unit.

When the sidewalls deflect or bend under load, the tread squeezes in

and distorts. The distortion affects the tires footprint and can decrease

traction and increases wear depending on the terrain. The tread

distortion also causes abrasion from the ground surface, which

reduces the life of the tire. These factors are why bias ply tires are not

idea for passenger car tires or as tires that my see highway use unless

used as tires for a towed trailer.

Bias Ply Strength - The way to increase the strength of bias-ply tires is

by increasing the number of plies and bead wires. More plies means

more mass which, increasing heat retention and reducing tire life.

Because of the bias ply inherent construction, sidewall strength is less

than that of a radial tire's construction and cornering is significantly

less effective. This is probably one of the main reasons bias ply tires

are not used for passenger cars and trucks.

However because of the bias ply construction and inherent strength of

a properly inflated tire, the bias ply is idea for straight line towing

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Bias ply advantages:

Strong sidewalls, tough casing

Good lateral stability (hill side work)

Good in rough terrain - generally used in mining

Good puncture resistance

Easily repaired

Easy to set up and maintain (pressure)

No power delivery problems

Lower purchase price

Bias ply disadvantages:

Poor life expectancy (50% of radial)

Lack of flexibility in casing reduces traction

Can't run at low pressures

Profile of tyre increases soil compaction and reduces traction

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Radial Ply Tyres:

Radial ply tires are made with the cord material running in a

radial or direct line from bead (at 90 degrees to the centerline of the tire),

and are typically made with one steel body ply or multiple body plies of

other materials. Under the tread area, the radial tire usually has three or four

Crossed plies or belts made of steel cord to stabilize the crown area and offer

better puncture resistance. The radial sidewall area is generally less stiff than

the bias ply sidewall, though the tread area is normally much stiffer.

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Performance and Purpose of a Radial Ply:

The construction of the radial tire makes it puncture-resistant. It also

gives a smoother ride and is quieter than other types of tires. The dual

construction of the radial plies and the belt plies allows the sidewall of the

tire to flex when under a load or when cornering, but still have the tread

remain flat on the road surface. This gives radials better traction and better

handling as well as longer life than non-radial tires. The radial constructionallows heat to dissipate, so radial tires run cooler and are less susceptible to

blowouts on the highway.

The advantages of radial tires make them a preferred choice for

passenger cars, but other vehicles can benefit from their characteristics as

well. Farm vehicles, off-road vehicles, trailers and aircraft can all benefit

from the traction, handling and heat dissipation afforded by radial tires.

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Radial ply advantages: Good high speed capacity

Low heat build-up

Low rolling resistance

Large contact area

Good grip, 40% greater than bias ply

Good availability of sizes. Proliferation of sizes in the last 10 years

has mostly been in radial (eg. 70, 65, 60, 55 series)

Radial ply disadvantages:

More prone to puncturing

More difficult to repair

Greater knowledge required for proper set-up and maintenance

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Difference between Bias Ply and Radial Ply Tyres:

Bias/Cross

plyRadial

Vehicle Steadiness Yes No

Cut Resistance:

Tread No Yes

Cut Resistance:

SidewallYes No

Repair ability Yes No

Self-Cleaning Yes No

Traction No Yes

Heat Resistance No Yes

Wear Resistance No Yes

Floatation No Yes

Fuel Economy No Yes

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Tyre Sidewall Information:

1. BIAS:

5.90 15

INFLATED SECTION WIDTH

(INCHES)

NOMINAL BEAD DIA

(INCHES)

2. Radial:

P 215 65 R 15 89 H

Passenger

Car

Section

width

Aspect

RatioRadial

Rim

Diameter

Load

Index

Speed

Rating

"P" means this is a passenger car tyre (as opposed to a tyre made for a truck

or other vehicle). P- metric is the U.S. version of a metric tyre-sizing system.

"215" Section Width: The width of the tyre in millimeters from sidewall to

sidewall. This measurement varies depending on the width of the rim to

which the tyre is fitted: larger on a wider rim, smaller on a narrow rim. The

number on the side of tyre indicates the width measured with the tyre fitted

to the recommended rim width.

"65" Aspect Ratio: The ratio of height to width; this tyre's height is 65% of

its width.

R" Construction: How the plies are constructed in the tyre carcass. "R"

means radial. "B" in place of the "R" means the tyre is belted bias

construction. "D" in place of the "R" means diagonal bias construction.

15" Rim Diameter: The diameter of the wheel in inches.

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"89" Load Index: This tyre has an industry-standard maximum load of 580

kilogram. Different numbers correspond to different maximum loads. The

maximum load is shown in lbs. (pounds) and in kg (kilograms), and

maximum pressure in PSI (pounds per square inch) and in kPa (kilopascals).

Kilograms and kilopascals are metric units of measurement.

"H" Speed Rating: This tyre has an industry-standard maximum service

speed of 210 km per hour. tyres using an older European system carry the

speed rating in the size description: 215/65HR15. Different letters

correspond to different maximum service speeds.

Calculation formula for tyre:

Example size: 225/45R17

The first three numbers in a typical size (225/45R17) are the tire's

indicated section width in millimeters, measured from sidewall to sidewall.

If you are familiar with measurements in inches, the section width in

millimeters can be converted into inches by dividing it by 25.4. For

example:

225mm / 25.4 = 8.86"

The second pair of numbers (225/45R17) is the tire's aspect ratio or

profile. This is a ratio of sidewall height to section width. The section

height's measurement can be calculated by multiplying the section width by

the aspect ratio. The answer will be the height of one sidewall. For example:

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225mmx0.45=101.3mm

8.86" x 0.45 = 3.99"

The last number (225/45R17) is the diameter of the wheel in inches. If

you are familiar with measurements in the metric system, the wheel diameter

can be converted into millimeters by multiplying it by 25.4. For example:

17" x 25.4 = 431.8mm

To calculate the overall diameter of a tire, the sidewall height must be

multiplied by 2 (remembering that the tire diameter is made up of 2

sidewalls, the one above the wheel and the one below the wheel touching the

ground) and add the diameter of the wheel.

101.3mm + 101.3mm + 431.8mm = 634.4mm

3.99" + 3.99" + 17" = 24.98"

http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

http://www.gtsparkplugs.com/TireCalculator.html

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http://www.kouki.co.uk/utilities/visual-tyre-size-calculatorhttp://www.gtsparkplugs.com/TireCalculator.htmlhttp://www.kouki.co.uk/utilities/visual-tyre-size-calculatorhttp://www.gtsparkplugs.com/TireCalculator.html


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Load Capacity Index chart: Load capacity index: means a number associated to the

reference mass a tyre can carry when operated in conformity with

requirements governing utilization specified by the manufacturer. A=Load-

capacity index, B=Corresponding mass of the vehicle which is to be carried.

A B A B A B A B A B

0 45 41 145 82 475 123 1550 164 5000

1 46.2 42 150 83 487 124 1600 165 5150

2 47.5 43 155 84 500 125 1650 166 5300

3 48.7 44 160 85 515 126 1700 167 5450

4 50 45 165 86 530 127 1750 168 5600

5 51.5 46 170 87 545 128 1800 169 5800

6 53 47 175 88 560 129 1850 170 6000

7 54.5 48 180 89 580 130 1900 171 6150

8 56 49 185 90 600 131 1950 172 6300

9 58 50 190 91 615 132 2000 173 6500

10 60 51 195 92 630 133 2060 174 670011 61.5 52 200 93 650 134 2120 175 6900

12 63 53 206 94 670 135 2180 176 7100

13 65 54 212 95 690 136 2240 177 7300

14 67 55 218 96 710 137 2300 178 7500

15 69 56 224 97 730 138 2360 179 7750

16 71 57 230 98 750 139 2430 180 8000

17 73 58 236 99 775 140 2500 181 8250

18 75 59 243 100 800 141 2575 182 8500

19 77.5 60 250 101 825 142 2650 183 8750

20 80 61 257 102 850 143 2725 184 9000

21 82.5 62 265 103 875 144 2800 185 9250

22 85 63 272 104 900 145 2900 186 9500

23 87.5 64 280 105 925 146 3000 187 9750

24 90 65 290 106 950 147 3075 188 10000

25 92.5 66 300 107 975 148 3150 189 10300

26 95 67 307 108 1000 149 3250 190 10600

27 97 68 315 109 1030 150 3350 191 10900

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28 100 69 325 110 1060 151 3450 192 11200

29 103 70 335 111 1090 152 3550 193 11500

30 106 71 345 112 1120 153 3650 194 11800

31 109 72 355 113 1150 154 3750 195 12150

32 112 73 365 114 1180 155 3875 196 12500

33 115 74 375 115 1215 156 4000 197 12850

34 118 75 387 116 1250 157 4125 198 13200

35 121 76 400 117 1285 158 4250 199 13600

36 125 77 412 118 1320 159 4375 200 14000

37 128 78 425 119 1360 160 4500

38 132 79 437 120 1400 161 4625

39 136 80 450 121 1450 162 4750

40 140 81 462 122 1500 163 4875

Speed Ratings:

Speed symbol Corresponding speed

Km/h

F 80

G 90

J 100

K 110

L 120

M 130N 140

P 150

Q 160

R 170

S 180

T 190

U 200

H 210

V 240

W 270

Y 300

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Wheel and Tyre:

Radial Tyre:

Front & Rear: 155/70R13

Bias Tyre:

Front & Rear: 4.50-10,8PR

Tyre Suitable for MUCS:

Maruthi Suzuki Omni

Maruthi eeco

Bajaj CG max Tata ace

Reva NXR

Price of Tyres:

Radial Tyre:

Bridgestone: Rs.3200

Goodyear: Rs.2800

Bias Tyre:

TVS Tyres: Rs.2000

Date post:	06-Apr-2018
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