Tyre Basics Passenger Car Tyres
Contents
1. Load index LI and maximum load per individual tyre Speed index SI Maximum speed for passenger car tyres 150 km h 93 mph 160 km h 99 mph 170 km h 106 mph 180 km h 112 mph 190 km h 118 mph 210 km h 130 mph 240 km h 150 mph 270 km h 169 mph 300 km h 187 mph exceeding 240 km h 150 mph P Q R 5 H V W it N poj 100 80 60 40 20 Tyre Inflation Pressure Modern tubeless tyres have very little in common with their predecessors dating from the start of last century apart from the basic principle of being pneumatic and containing compressed air It is the pressure inside that gives the tyre its stability and load carrying ability combined with the necessary elasticity Correct tyre pressure is vital for correct vehicle operation in different service conditions loads Speeds The optimal tyre pressure is defined in close consultation between the tyre and vehicle manufactur ers It is stated in the user manual and or indicated on the vehicle itself on the inside of the fuel tank flap for instance See also the Continental inflation pressure tables As tyre inflation pressure decreases so does the life expectancy of the tyre Inflation pressure in of the required value Tyre inflation pressure must be adjusted to suit various loads and operating conditions It should always be checked when the tyres are cold As inflation pressure always increases w2. Tyre Basics Passenger Car Tyres Winter Tyres Tyres marked M S are designed for winter Mud and Snow ETRTO definition This does not specify any defined winter performance Because most all year tyres offer insufficient winter perfor mance a series of test conditions and minimum requirements have been specified in the USA and are indicated by the snowflake symbol A tyre marked with the snowflake must offer a mini mum 7 96 improvement on braking performance on snow than that of a standard reference tyre Continental developed the first prototypes of a special winter tyre for use on snow and ice as early as 1914 Continental s first series made winter tyres were laun ched in 1952 Early winter tyres had massive bars they were loud hard and by today s standards only moderately suitable for winter use Also they could only be driven at relatively low speeds The real market breakthrough for winter tyres came with the development of special tread compounds for winter service and modern sipe technology fine slots in the tread Ice snow and low temperatures need not put moto rists at greater risks on the road By switching to win ter tyres one can still maintain a high margin of safety When temperatures drop winter tyres perform better Why winter tyres Performance features Dry Roads Wet Roads Snow Ice Comfort Rolling Noise Rolling Resistance Wear ETRTO European Tire an
3. 30 35 High performance Racing tyre tyre Modern radial tyres In modern car engineering the radial or belted tyre has completely replaced the cross ply tyre The cords in a radial tyre casing run perpendicular to the direction of travel Viewed from the side the cords run radially giving the tyre its name The weakness of this arrangement is that the cords cannot sufficiently absorb lateral forces when cornering or circumferential forces when accelerating To compensate this the cords must be supported or complemented by other Structural elements The belt assembly comprises several layers of steel belt plies arranged in diagonally opposing directions at a specified angle The belt assembly provides Support and stability to the tread area so that the forces in the 3 principal planes can be transmitted efficiently Many tyres are additionally stabilised by a nylon cap ply Like most tyre manufacturers Continental produces only modern radial tyres for passenger cars Tyre Basics Passenger Car Tyres 10 Materials used in a tyre The components of a modern radial tyre for passenger Cars contain diverse ingredients in differing amounts These ingredients vary by tyre size and tyre type Sum mer or winter tyre The example below shows the ingredients used in the Summer tyre 205 55 R 16 91W ContiPremiumContact 2 The tyre shown here weighs about 9 3 kg without the rim Breakdown of ingredien
4. Supplier industry and Compound production Various branches of industry supply the tyre industry with raw materials which are pre treated and further processed into individual semi finished products The steel industry supplies high strength steel This serves as the starting material for the manufacture of steel belts steel cord and of bead cores steel wire The chemical industry supplies a multitude of raw materials and supplies The main ones are synthetic rubber and materials used for instance to reduce wear increase grip and lengthen the life of the tyre Natural rubber is extracted by cutting into the bark of special trees grown in large plantations The milky fluid latex that flows out coagulates when acid is added to it It is then cleaned with water and pressed into solid bales for easier transportation and storage The textile industry supplies base materials rayon nylon polyester and aramid fibres for the manufacture of cord which serve as a reinforcing material in tyres Bales of natural and synthetic rubber are sectioned cut into portions weighed and mixed with other ingredients in accordance with specially defined recipes Up to twelve different rubber compounds are used today in the various integral components of modern passenger car tyres Manufacture of semi finished products Steel cord Pre treated steel cord is supplied on wire spools and fed into a calender via special spoolers In the
5. See section on Winter tyres 21 22 Tyre Basics Passenger Car Tyres Tyre Selection Tyre sizes which have been approved for a vehicle are specified in the vehicle s documents Each tyre must be suitable for the vehicle This applies to its outer dimensions diameter width which are indicated in the tyre s standardised size designation see page 19 Also the tyre must comply with the vehicle s requirements in terms of load and speed As far as load is concerned tyre selection is based on the maximum permissible axle load which is distributed among two tyres The maximum load capacity of a passenger car tyre is indicated by its load index 2 Correct choice of tyre also includes the speed rating the tyre s maximum speed must be at least equivalent to that of the vehicle plus tolerance The maximum permissible speed at full load of a tyre is indicated by its speed symbol GSY Together the LI and GSY make up the service description for a passenger car tyre This description is an official part of the complete standardised size designation appearing on each tyre and must conform to the information given in the vehicle documents The dimensions and technical properties of SSR runflat tyres correspond to those of standard tyres of the same size and construction SSR tyres may however only be mounted on vehicles with a tyre pressure monitoring system Exception winter tyres see page 24
6. Tyre Tips Tyre Selection Service Description 22 inflation Pressure v veo dup errPCP UE VETE 23 Winter Tyres a an Sua E eave ka Rad dE P VIRES 24 Tyre Storage PPPE v 26 Wheels and RIMS 000 ce eee eee eas 27 Tyre Basics Passenger Car Tyres Introduction The tyre is a complex technical component of today s motor cars and must perform a variety of functions It must cushion dampen assure good directional Stability and provide long term service Most important of all however it must be capable of transmitting strong longitudinal and lateral forces during braking acceler ating and cornering manoeuvres in order to assure optimal and reliable roadholding quality It must be able to do all of this even when the road provides little traction in wet or Slippery conditions or when the road is covered with Snow or ice In certain cases these wide ranging demands leave tyre engineers no choice but to settle for a compromise between opposing characteristics Vehicles with powerful engines require for example good grip particularly on wet roads On the other hand a corresponding improvement in the tread compound can affect tyre life rolling resistance and ride comfort see diagram One point however has absolute priority over all other tyre design objectives and that s safety Conflicting goals in tyre development Directional stability Tyre weight P d Servi
7. calender the steel cord is embedded in one or more layers of rubber This continuous sheet of cord and rubber is then cut at a defined angle to the right length for the tyre size and rolled up for further processing G Tread The kneadable material previously blended in the mixer is shaped into an endless strip by means of a screw type extruder After extrusion the weight per metre is checked and the tread cooled by immer sion The tread strip is cut to length for the tyre size and a unit weight control is carried out Textile cord A multitude of textile threads are fed into the calender by large rollers device There they are embedded in a thin layer of rubber This endless sheet is then cut to the desired width at a 90 angle relative to the direction of travel and rewound for further processing Steel bead The core of the bead is made up of many annular Steel wires each of which has its own rubber coating This hoop is then provided with a rubber apex Sidewall inner liner Sidewall sections cut to suit the particular tyre size and exhibiting various geometries are turned out with the extruder A calender forms the airtight inner liner into a wide thin layer Building and vulcanisation The various semi finished products discussed in the previous stages come together on the tyre buil ding machine and are assembled built into what is known as a green tyre in two stages casing and tread belt assembly P
8. table below shows just how important the amount of remaining tread is The braking distance for a worn tyre with a tread depth of 1 6 mm is almost twice as long as for a new tyre with about 8 mm tread depth Wet road E O 10 20 30 40 50 60 70 80 90 100 110 120 E Braking distance m Tyres have tread across their entire area Tread depth measurements must be taken in the main grooves which feature TWIs on modern tyres In most European countries the law specifies a minimum tread depth of 1 6 mm that s when tyres have to be replaced In order to ensure the tyres always offer best pos sible performance summer tyres should be replaced when they reach a depth of 3 mm and winter tyres when they reach a depth of 4 mm Also all four wheel positions should be fitted with tyres of the same tread pattern design and each axle at least should have tyres with the same tread depth Regrooving of passenger car tyres is prohibited Tread depth required by law TWI Tread Wear Indicator small raised bars across the main grooves The bars have a height of 1 6 mm and gradually become level with the tread as the tyre surface wears Continental winter tyres also have tread wear indicators with height of 4 mm They indicate the tread depth at which the tyre begins to lose its winter properties Recommendation One should avoid mixing summer and winter tyres in particular which is even illegal in some European countries
9. 425 Series In the early 1950s the steel radial tyre see page 8 set new standards in mileage and handling perfor mance By 1970 the former cross ply tyre had dis appeared from the passenger car market this didn t apply to truck tyres however Low profile tyres were invented at the same time and 7096 profile tyres were followed within just a few years by the 6096 and 5096 profile tyres see illustration page 6 A height width ratio of 6596 is standard for many vehicles today and modern tyres are getting even wider now having a height width ratio as low as 2596 These ultra low profile tyres are however built for special high performance cars The fact that tyres manufactured today by Continental are nothing less than high tech products is made very clear by the following details Since 1975 the maximum speeds possible with Continental tyres have risen from 210 km h to 360 km h while at the same time the weight of a tyre of average size has actually reduced from 11 6 kg to 8 kg Modern passenger car radials are made of up to 25 different structural parts and as many as 12 different rubber compounds The main structural elements are the casing and the tread belt assembly The casing cushions the tyre and contains the required volume of air In fact the air is the load carrier not the tyre The tread belt assembly provides a minimal rolling resist ance optiml handling and a long service life In the early days of tyre d
10. Tyre Basics Passenger Car Tyres i gt e aU ror eed e MOUNT ONLY ON OR RAD aig 91w 2008 09 Ayi e n e 3 o A 9 Tyre Basics Passenger Car Tyres Publisher s imprint The content of this publication is provided for information only and without responsibility Continental AG makes no representations about the accuracy reliability completeness or timeliness of the information in this publication Continental AG may in its sole discretion revise the information contained herein at any time without notice Continental AG s obligations and responsibilities regarding its products are governed solely by the agreements under which they are sold Unless other wise agreed in writing the information contained herein does not become part of these agreements This publication does not contain any guarantee or agreed quality of Continental AG s products or any warranty of merchantability fitness for a particular purpose and non infringement Continental AG may make changes in the products or services described at any time without notice This publication is provided on an as is basis To the extent permitted by law Continental AG makes no warranty express or implied and assumes no liability in connection with the use of the information contained in this publication Continental AG is not liable for any direct indirect incidental consequen tial or pun
11. ce life EN Rolling resistance Aquaplaning Compromises under wet braking conditions Optimisation of a single aspect has an impact on several others Steering precision o Ride comfort Wet braking Steps in the Development of the Pneumatic Tyre The wheel as such is not a natural phenomenon And yet it wasn t invented in the modern sense of the word For more than 5 000 years the wheel has been reinvent at different times and in different regions to meet current transportation needs In its earliest forms for example used in Mesopotamia or ancient Egypt the wheel was made as a solid disc with three segments held together by circular pieces of metal or leather The principle of a disc revolving on an axis was known from pottery making the wheel is thus an early example of technology transfer Contrary to wide misconception the wheel did not evolve from the use of tree trunk slabs cut horizontally because they re neither round nor durable enough for such purposes These awkward and clumsy wooden disc wheels were later developed into spoked wheels but only for more superior vehicles like war or ritual chariots Spoked wheels were lighter stronger and more stable but they were also much more technologically sophisticated The felloes often had large headed nails to prolong the wheels life Spoked wooden wheels lasted until the modern era of coaches and then usually with iron tyres Even the first Benz m
12. d Manufacture of production Semi finished products o Steel cord O AYA AAA ANA MN MM MANN pon MOM A mi MAN M qe M V M Wh A DA A WM PU WN ua PO O D NY QU N MMM m KOR RR NY ODO Nd LL KW W QO SES DOR KON E AY P Fl IXY F n 3 A steel industry rubber steel cord spools steel cord calen cutting steel cord steel cord steel portioning dering to size wire AN YANN ONY AMAN ON W M M V 000000000000 09096805 OX X RM AONE p N ONN a OROA I OORO N WW UEM Voan E y b INIMA portioning of raw ad extruder control of weight ad cooling 9 v b V WY b materials and supplies per metre chemical industry synthetic rubbers additives Textile cord Q J zc MK VEZ AMA J T MW n p M i V AD AQUA PORUM A M AM Ny M D m M ZA i production of cord fabric on textile cord calen cutting master batch rollers dering textile cord to size 4 hu My MM M V RY A RN T EXXON MMMM XERXES Steel bead NO ON WM MM rubber extraction natural rubber d unwinding of bead coating of bead rewinding wire wire of bead wire making up of production compound Sidewall inner liner T Y W VOV VOVVVOV VOV XW VN QM AMAA MAAK NA 8 es OR ANN WP M ARM ANN D MM VW M VW K T p i LH 3 rs E shaping into trans sidewall calenderi
13. d Rim Technical Organisation M amp S stands for mud and snow winter tyres than high performance summer tyres as they have a softer compound to grip the road better see illustration on page 25 When it gets cold outside winter tyres give superior performance on wet and slippery roads Winter tyres should be fitted when the temperature drops below 7 C It is not recommended to mix summer and winter tyres on passenger cars In most European countries moto rists are required to fit only summer tyres or only winter M amp S tyres to any one axle in some countries This also applies to all four tyre positions Winter tyres must satisfy certain requirements such that the minimum legal tread depth of 1 6 mm is no longer sufficient Winter tyres with a tread depth of 4 mm are at the limit of their winter capabilities Continental recommends that winter tyres are replaced at latest when a tyre tread depth of only 4 mm remains or are used only in the summer season Top safety in winter can be provided only by true winter tyres on all axle positions 4 tyres It is vital that winter tyres are always kept inflated at the correct pressure since the volume of air contained in the tyre decreases at very low temperatures See also page 23 Depending on the type and designation the maximum speed for winter tyres is 100 mph 160 km h speed index Q 118 mph 190 km h speed index T 130 mph 210 km h speed i
14. emperature stability of the tyre at higher test speeds C is sufficient to meet U S statutory requirements Identification for Brasil Identification for China 19 20 Tyre Basics Passenger Car Tyres Tread Pattern The first pneumatic tyres had a smooth tread with no pattern As automobiles became faster however there were increased problems with handling characteristics and road safety Therefore as early as 1904 Continental developed the first automobile tyre with a tread pattern Since then tread patterns have been continuously developed and optimised to incorporate for example ingenious tread block geometry and fine siping techniques Today smooth tread tyres or slicks are only found in motor racing Tyres used on public roads must have a tread pattern by law The main job of the tread pattern is to expel water which can affect the tyre s contact with the road in wet conditions In addition the tread pattern especially that of winter tyres provides grip and adhesion Long braking distance on worn tyres On wet roads at high speeds a wedge of water can build up between the tyre and the road surface The tyre may then start to lose road contact or aquaplane and the vehicle can no longer be steered Sufficient tread depth is vital not only in such extreme Situations Even at low speeds there is a greater risk of having an accident in wet weather if the tyres are worn The
15. evelopment the casing was made of square woven linen fabric embedded in rubber However the crossed threads of the fabric cut away at each other resulting in a relatively short tyre life This prompted Continental to introduce in 1923 a new cord fabric This featured a unidirectional arrangement of cords held in place by supporting threads and embedded in rubber Tyres incorporating the new fabric lasted much longer Tyre Basics Passenger Car Tyres Steps in the Development of the Pneumatic Tyre Cross ply tyres until about 1970 The casing of a cross ply tyre consists of a number of rubberised cord plies with edges wrapped around the bead wire the bead ensures that the tyre sits firmly on the rim The number of plies determines the load capacity of the tyre Cross ply tyres for passenger cars generally had between two and six rayon or nylon cord plies Even today van tyres are said to have a 6 8or 10 PR ply rating load carrying capacity based on the num ber of plies The individual cord plies of a cross ply tyre are arran ged in a criss cross pattern at a certain angle known as the cord angle This angle determines the tyre s characteristics An obtuse cord angle for example gives better ride comfort but reduces lateral stability An acute cord angle increases directional stability at the expense of ride comfort Radial tyre 1 ros C ply tyre 38 40 Standard tyre
16. from any heat source Avoid condensation Tyres must not come in contact with oil grease paint or fuel Dark Protect tyres from direct exposure to sunlight and artificial lighting with a high UV content Moderately ventilated Oxygen and ozone are particularly harmful Wheels and Rims What s the difference between a wheel and a rim When man began moving heavy loads by rolling them he started by using logs of trees Later on wooden slabs were cut from tree trunks and cut into round discs These discs had a hole in the centre to accom modate either a rigid or rotating axle After many inter mediate stages the wheel was given a hub which in a spoked wheel was connected with the wheel rim by spokes In order to protect the wheel from wear it usu ally had a leather or iron band It then stayed this way for several centuries At the end of the nineteenth century the motor car came along and with it the pneumatic tyre bringing a whole new era To attach the tyre to the wheel a steel rim was nee ded The first pneumatic tyres were firmly vulcanised on to the rim later they were fixed to the rim by means of complicated mechanisms but they were removable There was further development before rea ching today s conventional method of joining the tyre and rim To ensure that the tyre sat firmly on the rim the latter was equipped with outwardly arching flanges against which the tyre was pressed by compressed ai
17. hen the tyres are warm air must never be released Insufficient inflation pressu re puts stress on the tyre and leads to excessive heat build up in the flexing zone which then results in tyre damage The inflation pressure must always be the Same for all tyres on any one axle but it can vary from axle to axle on the front and rear axles for example The pressure should be checked regularly about every 2 weeks or before taking a long journey driving at high speed with heavy luggage An inflation level inappropriate to the amount of stress the tyre must withstand can have a considerable negative effect on the vehicle s handling Fuel consumption goes up as the tyre pressure goes down 108 140 106 130 a c 104 Tm 5 120 8 o O B op 2 We 110 5 o n 100 T Tyre inflation pressure required value 2 0 bar a lt gt s m e o The spare tyre should also be checked in order to ensure that it is available at all times Add an extra 0 2 bar to the inflation pressure of winter tyres This compensates for the lower outside temperatures during the winter months Valve caps must be screwed firmly into place as they protect the valve from dust and dirt Missing valve caps must be replaced immediately Major losses of air between tyre pressure checks indicate damage A qualified tyre fitter should be asked to investigate and eliminate the problem 23
18. itive damages arising out of the use of this publication Information contained herein is not intended to announce product availability anywhere in the world The trademarks service marks and logos the Trademarks displayed in this publication are the property of Continental AG and or its affiliates Nothing in this publication should be construed as granting any license or right to the Trademarks Without the express written consent of Continental AG the use of the Trademarks is prohibited All text images graphics and other materials in this publication are subject to the copyright and other intellectual property rights of Continental AG and or its affiliates Continental AG owns the copyrights in the Selection coordination and arrangement of the mate rials in this publication These materials may not be modified or copied for commercial use or distribution Copyright 2008 Continental AG All rights reserved TDC 06 2008 0130 1567 Contents Introduction s s okie rh Rv ee RADA RED REE ROO 4 Steps in the Development of the Pneumatic Tyre Coming Long Way ss eepbsrepiUTerTeduE REL 5 The Inside Story Material inside atyre aaan ee 10 Tyre Components s 9x5 sanaaa eaae 11 Components and Their Functions 12 Tyre Production A Glance Around the Factory 14 The Outside of a Tyre Information on the Sidewall Ls 18 Ttead PAC 222 24 etutieh pb esse c 333p 20
19. lateral sipes enable the tread blocks to flex and bite deeper into the ice or snow for better traction Enhanced traction thanks to additional bite 25 26 Tyre Basics Passenger Car Tyres Tyre Storage New tyres which are properly stored and handled lose virtually none of their properties and characteristics even over a period of several years When removing the tyre one should make a note of the wheel position by chalk marking the tyre FL for front left for example Certainly when it is time to change from summer to winter tyres one should use the opportunity to switch the wheels round from front to back and vice versa This results in better econo my particularly in the case of vehicles with front wheel drive When changing the wheel position always observe the recommendations in the car handbook Tyres with rims 1 bar Do not stand them upright Hang them PLL UIA AAV UYU NAW SND NONI WAV UA SU ANNAN eti AVIA RNY NN TNA NNN Caha 4 MAMMA RA yb FA ASASASASAVS 80646140 Ted Or pile them changing order every four weeks Tyres without rims Do not pile them do not hang them ww gue MASA UVU Www MAV SS SUARSALSUANAS We Stand them upright and rotate them every four weeks MANY WM RNY NANNY NASI m ty NIA Www M V UVU MAM wah MAV Www VAM t WANAWANIA A Storage place Cool 15 C to 25 C Shield tyres from sources of heat Minimum distance of 1 m
20. ndex H 150mph 240 km h speed index V or as of recently 168 mph 270 km h speed index W Vehicles designed for higher speeds than the respective winter tyres must exhibit a sticker clearly within the driver s range of view citing the maximum permissible speed for the M amp S tyres summer tyres d Exception Winter tyres with less than 4 mm tread depth for passenger cars which no longer count as winter tyres Not applicable in the UK One of the most crucial properties of a tyre is its grip on the road particularly in winter The following three components are the most critical for winter tyres It is the interaction of all three components which offers the best possible characteristics for meeting the many different surface conditions possible in winter Tyre compound Summer rubber compounds begin to harden below 7 C and no longer provide the levels of grip required The special technology offered by winter tyres means they remain flexible and offer sufficient grip even at low temperatures More grip thanks to more effective tyre compounds Tread pattern The tread pattern used on a winter tyre is particularly effective on snow and slush In these conditions the rotation of the wheel presses the snow into the wider grooves used on this type of tyre thereby generating additional traction Better traction thanks to deeper contact with snow Sipes When setting off rows of fine
21. nflat tyres Self Supporting Runflat 6 Tubeless 7 Continental tyres are marked in accordance with international regulations So the sidewall is marked with a circle containing an E and the number of the country of homologation This marking is followed by a multi digit homologation number s t 4 Netherlands Manufacturer s code Tyre factory tyre size and type Date of manufacture week year 2207 means the 22nd week of 2007 9 T W I Tread Wear Indicator A number of small raised bars run across the main grooves The bars have a height of 1 6 mm and gradually become level with the rest of the tread as the tyre wears see also page 21 Country of manufacture All other information applies to countries outside Europe Department of Transportation U S A department which oversees tyre safety standards U S load index for max Load Rating 615 kg per wheel 1356 lbs where 1 Ib 0 4536 kg 13 Tread beneath which there are 4 plies 1rayon ply 2 steel belt plies 1 nylon ply Sidewall the tyre casing consists of 1 rayon ply U S limit for max inflation pressure 51 psi 1 bar 14 5 psi Information for consumers based on comparison values with standard reference tyres standardised test procedures O Treadwear relative life expectancy of the tyre based on standard U S testing Traction A B or C wet braking capability of the tyre Temperature A B or C t
22. ng of the portable units extrusion inner liner textile industry various cords 14 AVN NN WX cutting the tread to size O0000000005288880000000000990 ANN e ENTOT va RAMAN AOOO N AOON NANO AOOO AOIN AOOO AOOO IOON WONO MM ANA QRRIQQQRRRNUUR ARIA AA YP bead ring QU QU JA 0000008 00000093 MM ARMANI control of unit weight applying the apex YM Building Vulcanisation Putting together the individual components of a tyre 5566000098 m OVV v NV YY NANO ROY E building of the pre treatment of the casing green tyre SNAAA AA AM BAAA VI EZ VAM UA DUN M Aw building of the tread belt assembly e I YN ee d YOO KAAADAL I NEM Me vulcanisation Each individual stage of production from the inspection of the raw materials through to delivery of the finished tyre is subject to ongoing quality control Quality control KAON NN KY O MAMANS WY PRO RXR KKK RRR RE final visual inspection ROARK XD X OKA RAY ANA NN RAIN Pt a o mta taie XX j y A XX 0 X ray control sgean RR ae check for imbalance COT DN hw NKU PORNO HOVNO PON force variation control QVE M 15 16 Tyre Basics Passenger Car Tyres The typical stages of production in a modern tyre factory are illustrated on the two previous pages
23. otor car introduced in 1886 which was l l l l Cross section of a tyre basically a motorised carriage still had spoked around 1910 wooden wheels albeit with solid rubber tyres Tyre Basics Passenger Car Tyres Steps in the Development of the Pneumatic Tyre The pneumatic tyre was invented later firstly for bicycles Dunlop 1888 and subsequently for automobiles In 1898 Continental started producing so called pneumatics tyres capable of giving a more comfortable cushioned ride and enabling automobiles to travel at higher speeds 1924 Ballon Continental also made a significant contribution towards further technical advances of the pneumatic tyre From 1904 onwards tyres featured a tread pattern see page 20 and were given their typical black colour The addition of carbon black made tyres tougher and more durable 1948 Super Ballon 1964 Around 1920 the cord tyre came from the U S A 82 Series see page 7 This tyre had a body made of cotton cord which was more resilient less susceptible to punctures and longer lasting The low pressure tyre Um or balloon inflated at just under 3 bar instead of the previous 5 bar or more was invented in the mid 1920s It was followed in the 1940s by the super balloon tyre which had a larger volume of air and 1971 better comfort 60 Series 1975 50 Series 1987 45 Series C 2 1993 35 Series d 77 1996 30 Series 2002
24. p provides grip on all road surfaces wear resistance and directional stability Base reduces rolling resistance and damage to the casing Shoulder forms an optimal transition from the tread to the sidewall J ointless cap plies Material Nylon embedded in rubber Functions Enhances high speed suitability Steelcord for belt plies Material High strength steel cords Functions Enhances shape retention and directional stability Reduces the rolling resistance Increases the tyre s mileage performance Textile cord ply Material Rayon or polyester rubberised Functions Controls internal pressure and maintains the tyre s shape Inner liner Material Butyl rubber Functions Seals the air filled inner chamber Acts as a tube in tubeless tyres 6 Side wall Material Natural rubber Functions Protects the casing from external damage and atmospheric conditions D Bead reinforcement Material Nylon aramid Functions Enhances directional stability Gives steering precision Bead apex Material Synthetic rubber Functions Enhances directional Stability 2 Gives steering precision Improves comfort O Bead core Material Steel wire embedded in rubber Functions Ensures that the tyre sits firmly on the rim 13 Tyre Basics Passenger Car Tyres Tyre Production A Glance Around the Factory Supplier industry o Compoun
25. r The basic structure has remained the same since then alt hough the rim s cross sectional shape has changed in the course of further development The rim is therefore not a wheel but rather part of a wheel Spokes or a metal nave connect the rim to the vehicle Wheel nave Rim offset Inner contact surface 27 28 Tyre Basics Passenger Car Tyres Wheels and Rims Rim wheel nave disc wheel For modern vehicle construction the rim offset is cru cial For this reason it may be altered only slightly even if changes are made in the axle geometry The rim offset mm is the distance measured from the centre of the rim of a disc wheel to the inside contact face of the wheel disc where it presses against the hub flange This value can be either positive or nega tive The following points must be observed when fitting tyres to rims tyre and rim must correspond in terms of diameter and must be approved in that combination for the vehicle type It is essential that the rims used 1 Drop centre rim normal are dimensionally accurate clean and rust free and 2 Hump rim safety contour neither damaged There are several rim contours 3 Ledge rim safety contour Thanks to slight curvatures rims 2 and 3 guarantee the tubeless tyre sits firmly on the rim Indeed such rims are abso lutely essential for tubeless radial tyres Passenger car hump rim Rim wid
26. rior to vulcanisation the green tyre is spray ed with a special fluid In the curing press it then receives its final shape after being vulcanised for a certain time at a certain pressure and temperature During the process the raw rubber undergoes a change in its physical properties to become rubber Also the press moulds are engraved to give the tyre its tread pattern and sidewall markings Final quality control and shipment After vulcanisation the tyres undergo visual inspec tion and X raying as well as various tyre uniformity checks Once the tyres have passed all the checks and inspections they are sent to the distribution ware house for shipment Individual tyre components and their functions are described in detail on pages 12 and 13 17 18 Tyre Basics Passenger Car Tyres The tyre viewed from the outside Abbreviations DOT U S Department of Transportation ETRTO European Tyre and Rim Technical Organisation Brussels ECE FMVSS Economic Commission for Europe UN institution in Geneva Federal Motor Vehicle Safety Standards U S safety code Sidewall markings standard and required by law 1 Manufacturer trademark or logo 205 Tyre width in mm 55 Height to width ratio in percent R Radial construction 16 Rim diameter in inches code 4 91 Load index see also page 22 V Speed index see also page 22 5 SSR Special designation SSR for ru
27. th Tapered seat Flange Ip ntr l i i Diameter Example 6 1 2 J x 16 H2 B ET 45 to DIN 7817 6 1 2 Rim width in inches J Flange type X Drop centre hen mE f 16 Diameter ances r e LI rim is a is ety rim of the kin nS on H2 Double hump icycles motorcyc ES passenger cars agricu wia and other commercial vehicles The drop centre is B Asymmetrical drop centre ET45 Rim offset in mm necessary in fitting the tyre on the rim 29 0130 1567 Copyright 2008 Continental AG All rights reserved www continental tyres com NEM n n n i b e OAO
28. ts Tyre example ContiPremiumC ontact 2 205 55 R 16 91W Rubber natural and synthetic rubber Fillers carbon black silica carbon chalk Reinforcing materials steel polyester rayon nylon Plasticizers oils and resins Chemicals for vulcanisation sulphur zinc oxide various other chemicals Ant ageing agents and other chemicals 30 Tyre Components Every modern passenger car tyre has a complex structure 4 4 i A modern tyre is made up of Tread belt assembly consisting of e Tread high mileage good road grip and water expulsion J ointless cap plies enable high speeds Steel cord belt plies optimise directional stability and rolling resistance Casing consisting of Textile cord ply controls internal pressure and maintains the tyre s shape Inner liner makes the tyre airtight Side wall protects from external damage Bead reinforcement promotes directional stability and precise steering response Bead apex promotes directional stability steering performance and comfort level Bead core ensures firm seating on the rim The functions of the individual components are explained on the next two pages 17 Tyre Basics Passenger Car Tyres Components and Their Functions Tread Belt Assembly s Shoulder o S e 0 3 mm la Carcass Tread M aterial Synthetic and natural rubber Functions Ca
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