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Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

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“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 15709 (2006): Automotive vehicles - retreaded pneumatictyres for passenger car [TED 7: Automotive Tyres, Tubes andRims]

IS 15709:2006

Wmm-1-w-w%mwt(qRR=Rm-W-fafm?

Indian Standard

AUTOMOTIVE VEHICLES — RETREADED PNEUMATICTYRES FOR PASSENGER CAR— SPECIFICATION

ICS 83.160.10; 43.040.50

0 BIS 2006

BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

October 2006 Price Group 7 .

Automotive Tyres, Tubes and Rims Sectional Committee, TED 7

FOREWORD

This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Automotive Tyres,Tubes and Rims Sectional Committee had been approved by the Transport Engineering Division Council.

In the formulation of this standard, assistance has been derived from the following:

ECE 108 Uniform provisions concerning the approval for the production of retreaded pneumatic tyres for motorvehicle and their trailers

The following Indian Standards may be referred for valve, valve accessories and terminology of automotive vehicles:

IS No. Title

9081:2001 Automotive vehicles —Valves and valve accessories for pneumatic tyres — Specification(third revision)

10939:2000 Designation system for tyre tube valves for automotive vehicles (/irs/ revision)

14272 (Part 1) :1995 Automotive vehicles — Types — Terminology: Part 1 Three and four wheelers

In this standard S1units have been used, the unit of force, in Newton (N), oftyre load, in kilogram (kg) and of pressure,in Pascal (Pa). Their relationship are given below for information:

1 kgf = 9.80665 N

1 kgf/cm2 = 98,066 kpa

For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observedor calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2: 1960 ‘Rules forrounding off numerical values (revised)’. The number of significant places retained in the rounded off value should bethe same as that of the specified value in this standard.

IS 15709:2006

Indian Standard

AUTOMOTIVE VEHICLES — RETREADED PNEUMATICTYRES FOR PASSENGER CAR — SPECIFICATION

1 SCOPE

This standard prescribes to the production of retreadedtyres intended to be fitted to passenger cars and theirtrailers used on the road. It does not however apply to:

a)

b)

c)

d)

e)

f)

Retreaded tyres for commercial vehicles and theirtrailers,

Retreaded tyres with a speed capability below120 km/h or above 240 kmlh (limit of below120 krnh is not applicable for bias-ply tyres),

Tyres for cycles and motor cycles,

Tyres originally produced without speed symboisand load indices,

Tyres designed exclusively for competition or offroad use and marked accordingly, and

Tyres designated as ‘T’ type temporary use spares.

2 REFERENCES

The following standards contain provisions which throughreference in this text, constitute provisions of this standard.At the time of publication, the editions indicated werevalid. All standards are subject to revision and parties toagreements based on this standard are encouraged toinvestigate the possibility of applying the mast recenteditions of the standards indicated below:

IS No. Ztle

10694 (Part 2) : Automotive vehicles — Rims —1991 General requirements: Part 2 Passenger

car (f?rst revision)

15633: 20Q5 Automotive vehicles – Pneumatic tyresfor passenger car vehicles — Diagonaland radial ply — Specification

3 DEFINITIONS

3.1 The nomenclature used is given in Fig. 1.

3.2 Structure — Technical characteristics of the tyrecarcass. The following structures are distinguished inparticular:

a) Diagonal or bias-ply — A pneumatic tyre structurein which the ply cords extend to the beads and arelaid at alternate angles of substantially less than 90°to the centerline of the tread.

1

b)

c)

.

Bias-belted — A pneumatic tyre structure ofdiagonal (bias-ply) type in which the carcass isstabilized by a belt, comprising two or more layersof substantially inextensible cord material laid atalternate angles close to those of the carcass.

Radial — A pneumatic-tyre structure in which theply cords extend lo the beads and are laidsubstantially at 90° to the centreline of the tread,the carcass being stabilized by an essentiallyinextensible circumferential belt.

3.3 Category of Use

3.3.1 Normal Tyre — A tyre intended for normal road useonly.

3.3.2 Special Use Tyre — A tyre intended for mixed use,both on and off road andlor at restricted speed.

3.3,3 Snow Tyre — A tyre whose tread pattern, or treadpattern and structure is primarily designed to ensure, inmud and fresh or melting snow, a performance better thanthat of a normal tyre. The tread pattern of a snow tyregenerally consists of groove (rib) and solid block elementsmore widely spaced than on a normal tyre.

3.4 Bead — Part of a pneumatic tyre which is of suchshape and structure as to fit the rim and hold the tyre on it.

3.5 Cord — Strands forming the fabric of the plies inpneumatic-tyre.

3.6 ply — A layer of rubber-coated parallel cords (seeFig.1).

3.7 Belt — Applies to a radial ply or bias-belted tyre andmeans a layer or layers of material or materials underneaththe tread, laid substantially in the direction of the centreline of the tread to restrict the carcass in a circumferentialdirection.

3.8 Breaker — Applies to a diagonal ply tyre and meansan intermediate ply between the carcass and tread.

3.9 Protective Brea-ker — Applies .to a radial ply tyreand means an optional intermediate ply between the treadand belt to minimize damage to the belt.

IS 15709:2006

1

\\\\‘1”,IIIIII

—

1

.E! —

2

IS 15709:2006

3.10 Chafer — Material in the bead area to protect thecarcass against chafing or abrasion by the wheel rim.

3.11 Carcass — Structural part of a pneumatic-tyre otherthan the tread and outermost rubber side walls which, wheninflated, supports the load.

3.12 Tread — Part of a pneumatic-tyre which is designedto come into contact with the ground, protects the carcassagainst mechanical damage and contributes to groundadhesion.

3.13 Side Wall — Part of a pneumatic-tyre between thetread and the area designed to be covered by the rim flange.

3.14 Lower Area of ~re — Area included between theline of maximum section width of a tyre and area designedto be covered by the edge of rim.

3.15 Tread Groove — Space between the adjacent ribsor blocks in the tread pattern.

3.16 Section Width — Linear distance ‘between theoutsides of the side walls of an inflated’pneumatic tyre,when fitted to the specified measuring rim, and excludingelevations due to labelling (marking), decoration orprotective bands or ribs.

3.17 Overall Width — Linear distance between theoutsides of the sidewalls of an inflated pneumatic tyre,when fitted to the specified measuring rim and includinglabelling (marking), decoration and protective bandsor ribs.

3.18 Section Height — Distance equal to half thedifference between the outer diameter.of the tyre and thenominal rim diameter.

3.19 Nominal-Aspect Ratio (R,) — One hundred timesthe number obtained by dividing the number expressingthe nominal section height by the number expressing thenominal section width, both dimensions being in the sameunits.

3.20 Outer Diameter — Overalldiarneter of an inflated,newly retreaded tyre.

3.21 Tyre-Size Designation — A designation showing:

a) Nominal section width — This is expressed inmillimetres, except in cases of tyres for which thesize designation are given in the COI2 of Tables7to 12 in IS 15633.

b) Nominal aspect ratio — This is expressed in formof a number, except in cases of tyres for which thesize designation is shown in the CO12 of Tables7 to 12 in IS 15633.

c) A conventional number ‘d‘— Denoting the nominalrim diameter of the rim and corresponding to itsdiameter expressed either by codes (numbers below100) or in millimetres (numbers above 100).Numbers corresponding to both types ofmeasurements may be used in the designation.

3.22 Nominal Rim-Diameter (d) — Diameter of the rimon which a tyre is designed to be mounted.

3.23 Rim — “The support, -either for a tyre-and-tubeassembly, or for a tubeless tyre, on which the tyre beadsare seated [see IS 10694 (Part 2)].

3.24 Chunking — Breaking away of pieces of rubberfrom the tread.

3.25 Cord Separation — Parting of the cords from theirrubber coating,

3.26 Ply Separation — Parting .ofadjacent plies.

3.27 Tread Separation —.Pulling away of the tread tl-omthe carcass.

3.28 Service Description — Specific combination of theload index and speed symbol of the tyre.

3.29 Load Index — A numerical code which indicatesthe load the tyre can carry at the speed corresponding tothe associated speed symbol and when operated inconformity -with the service conditions specified by themanufacturer. A pneumatic tyre can have more than oneload index to indicate its load capacity when used in singleor dual formation. The list of load indices and thecorresponding load is given in Table 1.

3.30 Speed Symbol — An alphabetical symbol indicatingthe speed at which the tyre can carry the load given by theassociated load index as given in Table 2.

3.31 Maximum Load Rating — The maximum masswhich the tyre is rated to support.

3.31.1 For speed not exceeding 210 km/h the maximumload rating shall not exceed the value associated with theload index of the tyre.

3.31.2 For speed higher than 210 krnih, but not exceeding240 krnh (tyres classified with Speed Category Symbol‘V’) the maximum load rating shall not exceed thepercentage of the value associated with the load index ofthe tyre, indicated in the Table 3, with reference to thespeed capability of the car to which the tyre is fitted.

3.32 Retreading Production Unit — Group of localizedsites where finished retread tyres are produced.

IS 15709:2006

Table 1 Load Indices(Clause 3.29)

Load Corresponding Load Corresponding Load CorrespondingIndex

Load CorrespondingMaximum Load Index Maximum Load Index Maximum Load Index Maximum Loadto be Carried, to be Carried, -to be Carried, to be Carried,

(1) $) (1) 5) (1) (5 (1) ?)

o

1

2

3

4

5

6

7

8

9

10

11

12

13

14

1“5

16

17

It?

19

20

21

22

23

24

25

26

27

28

29

30

45

46.2

47.5

48.7

50

5“1.5

53

54.5

56

58

60

61.5

63

65

67

69

71

73

75

77.5

80

82.5

85

87.5

90

92.5

95

97.5

I00

103

106

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

109

112

115

118

121

125

128

132

136

140

I45

I50

155

160

165

170

I75

180

185

I90

195

200

206

212

218

224

230

236

243

250

257

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

265

272

280

290

300

307

315

325

335

345

355

365

375

387

400

412

425

437

450

462

4r5

487

500

515

530

545

560

580

600

615

630

93

94

95

96

97

98

99

100

10I

I02

103

104

105

106

107

108

109

Ilo

Ill

112

113

114

115

116

117

118

119

120

650

670

690

710

730

750

775

800

825

850

875

900

925

950

975

1000

I 030

1060

1090

1 120

1 150

1180

I 215

1250

I 285

I 320

I 360

I 400

3.33 Retreading — The generic term for reconditioning the lower area of the tyre.a used tyre by replacing the worn tread with new material.It may also include renovation of the outermost sidewall 3.34 Casing –- The worn tyre comprising carcass andsurface. It covers the following process methods: remaining tread and sidewall material.

a) Top capping — Replacement of the tread.

b) Re-capping — Replacement of the tread and with3.35 Buffing — Process of removing old material from

the new material extending over part of the sidewall.the casing to prepare the surface for the new material.

.

c) Bead-to-bead — Replacement of the tread and 3.36 Repair— Remedial work carried out to the damagedrenovation of the sidewall including all or part of casings within recognized limits.

4

Table 2 Speed Category Symbol andMaximum Speed (km/h)

(Clause 3.30)

St Speed Category Maximum SpeedSymbol kmlh

H (2) (3)

i) L 120

ii) M 130

iii) N 140

iv) P 150

v) Q 160

vi) R 170

vii) s 180

viii) T 190

ix) u 200

x) H 210

xi) v 240

Table 3 Load Rating for Tyres Designated ofSpeeds 210 to 240 km/h

(Clause 3.3 1.2)

S1No. Maximum MaximumSpeed Load Ratingkm/h Percent

(1) (2) (3)

O 215 98.5

ii) 220 97

iii) 2>5 95.5

iv) 230 94

v) 235 92.5

vi) 240 91

NOTE — For intermediate maximum speeds linear interpolationsof the maximum load rating are permissible.

3.37 Tread Material — Material in a condition suitablefor replacing the worn tread. It can be in several formsfor example:

a)

b)

c)

Camel-back — Pre-cut lengths of material whichhave been extruded to give the required cross-section profile and subsequently fitted cold to theprepared casing. The new material must be cured.

Strip-wound— A ribbon of tread material which isdirectly extruded and wound on to the preparedcasing and build up to the required cross-sectionalcontour. The ne’wmaterial must be cured.

Direct extrusion — Tread material extruded to givethe required cross-sectional profile and directlyextruded on the prepared casing. The new materialmust be cured.

IS 15709:2006

d) Pre-cured — The previously formed and curedtread applied directly to the prepared casing. Thenew material must be bonded to the casing.

3.38 Sidewall Veneer — Material used to cover thesidewalls of the casing thereby allowing the requiredmarkings to be formed.

3.39 Cushion Gum — Material used as a bonding layerbetween new tread and casing and for repairing minordamage.

3.40 Cement — An adhesive solution to hold newmaterials in place prior to the curing process.

3.41 Cure — The terms used to describe the change inphysical properties of the new material which is broughtabout usually by the application of heat and pressure for aset period of time under controlled conditions.

3.42 Radial Run Out — Variation in radius of the tyre,measured around the outer circumference of the treadsurface.

3.43 Imbalance — A measurement of the variation indistribution of mass around the centre axis of the tyre, Itcan be measured as either’ Static’ or ‘Dynamic’ imbalance.

4 REQUIREMENTS

4.1 Tyres which have been previously retreaded shallnot be accepted for further retreading (Not applicablefor bias-ply tyres).

4.2 The age of the casing accepted for retreading shallnot cxcee.d 7 years, based on the digits showing the yearof manufacture of the original tyre; that is, the tyre markedwith a month and year code or date code.

4.3 Conditions Before Retreading

4.3.1 Tyres shall be clean and dry before inspection.

4.3.2 Before buffing, each tyre shall be thoroughlyexamined both internally and externally to ensure itssuitability for retreading.

4.3.3 Tyres, where damage is visible which has resultedfrom overload or under inflation shall not be retreaded.

4.3.4 ~res showing any of the following damage shallnot be accepted for retreading.

a)

b)

extensive cracking extending through to the carcass;

carcass penetrations or damage to casings above‘H’ speed symbol except where these casings areto be dawn rated to a lower speed symbol;

5

‘IS 15709:2006

c)

d)

e)

f)

g)

j)

k)

carcass break up;

appreciable oil or chemical attack;

multiple damage too close together;

damaged or broken bead;

non-repairable deterioration of or damage to innerliner;

bead damage other than minor rubber only damage;

exposed cords due to tread wear or sidewallscuffing;

m) .non-repairable tread or sidewall material separationfrom the carcass;

n) structural damage in the area of the sidewall; and

.p) deterioration due to weathering effect.

4.3.5 Radial ply tyre carcasses with separation in thebelt, other than slight belt edge looseness, shall not beaccepted for retreading.

4.4 Preparation

4.4.1 Atler butllng, and before the application of newmaterial, each tyre shall be thoroughly re-examined at leastexternally to ensure its continued suitability for retreading.

4.4.2 The entire surface to which new material is to beapplied shall have been prepared without overheating. Thebuffed surface texture shall not contain deep buffinglacerations or loose material.

4.4.3 Where procured material is to be used the contoursof the prepared area shall meet the requirements of thematerial manufacturer.

4.4.4 Loose cord ends are not permissible.

4.4.5 Casing cords shall not be damaged during thepreparation process.

4.4.6 Bufling damage to the belt of radial tyres shall belimited to localized damage to the outermost layer only.

4.4.7 Buffing damage limits for diagonal ply tyres shallbe as follows:

a)

b)

c)

d)

For two ply construction, there shall not be anydamage to the carcass except for slight localizedbuffhg damage to the casrng joint.

For two ply plus breaker construction of tubelesstype tyres, there shall not be any damage to thecarcass or breaker.

For two ply plus breaker construction of tubetype tyres, localized damage to the breaker ispermissible.

For four ply or more construction of tubeless type

6

e)

4.4.8

tyres, there shall not be any damage to the carcassor breaker.

For four ply or more construction of tube type tyres,damage shall be limited to the outermost ply in thecrown area only.

Exposed steel parts shall be treated as soon aspossible with appropriate material as defined by themanufacturer of that appropriate material.

4.5 Retreading

4.5.1 The retreader must ensure that either themanufacturer or the supplier of repair materials, includingpatches, is responsible for the following:

a)

b)

c)

d)

e)

Defining method(s) of application and storage, ifrequested by the retreader, in the local language ofthe state in which the materials are to be used;

Defining limits of damage for which the materialsare designed, if requested by the retreader, in thenational language of the country in which thematerials are to be used;

Ensuring that reinforced patches for tyres, ifcorrectly applied in carcass repairs, are suitable forthe purpose;

Ensuring that patches are capable of withstandingtwice the maximum inflation pressure as given bythe tyre manufacturer; and

Ensuring the suitability of any other repair materialsfor the service intended.

4.5.2 The retreader shall be responsible for the correctapplication of the repair material and for ensuring that therepair is free from any defects which may affect thesatisfacto~ service life of the tyre.

4.5.3 The retreader shall ensure that either the manufactureror the supplier of tread and sidewall material issuesspecifications concerning the conditions of storage anduse of the material in order to guarantee the qualities ofthe material. If requested by the retreader, this informationshall be in the local language of the state in which thematerials are to be used,

4.5.4 The retreader must ensure that the repair materialamlor compound is documented in a manufacturer’s orsupplier’s certificate. The material compound shall be asper the details/specification of retreading materialspecifications/retreader. Bonding gum, cushion gum,vulcanizing solution and tread rubber used for tyreretreading shall be ‘compatible and preferably be of thesame make.

4.5.5The processed tyre shall be cured as soon as possibleafter the completion of all repairs and building-up

operations and at the latest, according to the materiaImanufacturer’s specifications,

4.5.6 The tyre shall be cured for the length of time and atthe temperature and pressure, appropriate to, and specifiedfor the materials and processing equipment used.

4.5.7 The dimensions of the mould shall be appropriateto the thickness of the new material and the size of thebuffed casing. Radial ply tyres, when moulded, shall l)ecured in radial or radially divided moulds only.

4.5.8 The thickness of original material after butling andthe average thickness of any new material under the treadpattern.afier retreading is given in 4.5.8.1 and 4.5.8.2.

4.5.8.1 ForradM ply and bias belted tyres (nun) (see Fig. 2)

1.55(A+@~5 : M% 1,5 mm; MUX5:0 mm

A~l A4in 1.00 mm

B z ().5 Min 0.5 mm

4.5.8.2 For diagonal (Bias-ply) tyres:

a)

b)

c)

Thickness of original material above the breakershall be> 0,00 mm.

Average thickness of new material above the buffedcasing line shall be z 2.00 mm.

Combined thickness of original and new materialbeneath the base of the grooves of the treadpattern shall be z 2,00 ands 5.00 mm,

.n

x——

IS 15709:2006

4.5.9 The service description of a retreaded tyre shall notshow either a higher speed symbol or a higher load indexthan that of the original, first life, tyre.

4.5.10 The minimum speed capability of a retreaded tyreshall be 120 km/h (’L’ speed symbol) except for bias-plytyres and the maximum speed capability shall be240 krdh (’V’ speed symbol).

4.5.11 Tread wear indicators shall be incorporated asfollows:

a)

b)

c)

d)

The retreaded pneumatic tyre shall include not Iessthan six transverse rows of wear indicators,approximately equispaced and situated in theprincipal grooves of the tread, The tread wearindicators shall be such that they cannot be confusedwith the material ridges between the ribs or blocksof the tread.

However, in the case of tyres designed for mountingon rims of a nominal diameter of code 12 or less,four rows of tread wear indicators are permissible.

The read wear indicators shall provide a means ofindicating, with a tolerance of T}$0mm, whenthe tread grooves are no longer more than 1.6 mmdeep,

The height of the tread wear indicators shall bedetermined by measuring the difference betweenthe depth from the tread surface to the top of thetread wear indicators and the base of the treadgrooves, close to the slope at the base of tread wearindicators.

I?D. = Pattern depthx =Buff lineA = Average thickness of new material under patternB = Minimum thickness of original material above belt

after buffing (Cords shall not be visible)

1

FIG.2 PATTERNDEPTHANDBUFFLINE

7

IS 15709:2006

4.6 Inspection

4,6.1 Atler curing, whilst adegree of heat is retained in atyre, each retreaded tyre shall.be examined to ensure that

, it is free from any apparent defects. During or afterretreading the tyre must be inflated to at least 1.5 bar forexamination. Where there is any apparent defect in theprofile of the tyre (for example blister, depression etc),the tyre shall be specifically examined to determine thecause of this defect.

-4.6.2 Before, during or after retreading the tyre shall bechecked at least once for the integrity of its structure bymeans of a suitable inspection method.

4.6.3 For the purposes of quality control, a number ofretreaded tyres shall be subjected to destructive and/ornon-destructive testing or examination. The quantity oftyres checked and the results shall be recorded.

4.6.4 After retreading, the dimensions of the retreadedtyre, when measured in accordance with Annex A, shallconform either to the dimensions calculated according tothe procedures given in 5 or to those given in Annex A ofIS 15633. Note that the maximum outer diameter of aretreaded tyre may be up to 1.5 percent greater than themaximum outer diameter of-a new original tyre.

4.6.5 The radial run out of the retreaded tyre shall notexceed 1.5 mm (+0.4 mm measuring tolerance).

4.6.6 Tread wear indicators shall conform to therequirements given in 4.5.11.

5 TYRE DIMENSIONS

5.1 The retreaded tyres shall be tested as per method giveninAnnex A and shall conform to the following dimensions:

5.1.1 Section Width

5.1.1.1 The section width shall be calculated by using thefollowing formula:

S= S,+ K(A-AI)

where

S = actual section width as measured on the test rim,in miliimetres;

S, = value of the ‘design section width’, referred tothe measuring rim, as quoted in the InternationalTyre Standard specified by the retreader for thetyre size in question;

A = width of the test rim, in mm;

A, = width, in mm, of the measuring rim as quoted in

the International Tye Standard specified by theretreader for the tyre size in question; and

K = factor shall be taken 0,4.

5.1.1.2

a) Actual overall width may be less than the sectionwidth or widths determined in 5.1.1.1;

b) Actual overall width may also exceed the value orvalues determined in 5.1.1.1 by:

1) 4 percent in the case of radial ply tyres;’

2) 6 percent in the.case of diagonal (bias-ply) orbias-belted tyres; and

3) In addition, if the tyre has a special protectiveband, the width may be greater by up to 8 mmover the tolerances given in(1) and (2).

5.1.2 Outer Diameter

5.1.2.1 The theoretical outer diameter of a retreaded tyreshall be calculated by the following formula

D=d+2H

where

D = theoreticalouter diameter, in mm;

d = conventional number defined in 3.21(c), in mm,

H = nominal section height, in mm and is equal to S.multiplied by 0.01 R,;

Sn = nominal section width in millimetres; and

R,= nominal aspect ratio.

All of the above symbols are as quoted in the tyre sizedesignation as shown on the sidewall of the tyre inconformity with the requirements as defined in 3.21.

5.1.2.2 The actual outer diameter of a retreaded tyre mustnot be outside the values of D~inand DMWobtained by thefollowing formulae:

DMiR=d + (2H x a)

DM~X=d+ (2H X b)

wherea) Coefficients a and b are respectively as follows:

b)

coet%cient a = 0.97

Radial Diagonali’jv-es (Bias-ply) and

Bias-Belted Tyres

coeillcient b

for normal use lyres 1.04 1.08

For snow tyres the maximum outer diameter (DMJ

calculated in 5.L2.2 may be exceeded by not morethan 1 percent.

8

-6 LOAD/SPEED PERFORMANCE TEST

6.1 Each type of retreaded tyres shall undergo Icmdlspeedperformance test as specified in Annex B (see Table 5).

.6.2 A retreaded tyre which after undergoing the loadhpeedperformance test does not exhibit any tread separation,ply separation, cord separation, chunking or broken cordsshall be deemed to have passed the test.

7 ENDURANCE TEST

7.1 Each type of retreaded tyres shall undergo at leastone endurance test as per method given in Annex C(see Table 6). “

7.2 A tyre which after undergoing the endurance test doesnot exhibit any tread separation, ply separation, cordseparation, chunking or broken cords shall be deemed tohave passed the test.

8 TYRE STRENGTH TEST

The tyrestrength test (Plunger test) shall be carried out ona tyre in accordance with method given in Annex D (seeTables 7 and 8).

The minimum breaking energy value at any measuringpoint shall not be less than the value mentioned inAnnex D (see Tables 7 and 8J.

9 MARKINGS

9.1 Retreaded tyres shall display following markings onboth sidewalls in the case of symmetrical tyres and at leaston the outer sidewall in the case of asymmetrical tyres:

a) Brand name or trade-mark.

b) Tyre size designation as defined in 3.21.

c) An indication of the structure as follows:

1)

2)

3)

On diagonal (bias-ply) tyres, no indication, orthe letter ‘D’ placed in front of the rim-diametermarking;

On radial-ply tyres: the letter ‘R’ placed in frontof the rim-diameter marking and optionally, theword ‘RADIAL’; and

On bias-belted tyres, the letter ‘B’placed in frontof the rim-diameter marking, anc.in addition theword ‘BIAS-BELTED’

d) The service description comprising

1)

2)

3)

Speed-category symbol (or symbols),

An indication of the tyre’s nominal load capacityin the form of the load index prescribed in 3.29,and

An indication of the tyre’s nominal speedcapability in the form of the symbol prescribedin 3.30.

9

e)

f)

!3)

h)

IS 15709:2006

The word ‘TUBELESS’, if the tyre is designed foruse without an inner tube.

The inscription M+S or MS or M.S. or M&S, inthe case of snow ~re.

The date of retreading as follows: In the form ofmonth and year code in which the tyre wasretreaded. For example, the marking MAR 04 couldindicate a tyre which was retreaded in month Marchof the year 2004. (OR) In the form of a group offour digits, the first twoshowing the week numberand the second two showing the year in which thetyre was retreaded. The date code can cover a periodof production from the week indicated by the weeknumber up to and including the week number plusthree. For example, the marking ‘2504’ couldindicate a tyre which was retreaded in weeks 25 ofthe year 2004.

This date code may be marked on one side wallonly.

The term ‘RETREAD’. At the request ofretreader,the same term in other languages may also be added.

9.2 The markings referred to in 9.1 shall be clearly legibleand moulded on to or into-the tyre or permanently markedon to the tyre.

9..3 As far as any of the original manufacturer’sspecifications are still legible after the tyres have beenretreaded, they shall be regarded as specifications of theretreader for the retreaded tyre. If these originalspecifications do not apply after retreading they shall becompletely removed.

9.4 The number of times tyre retreaded shall be markedon the tyre.

9.5 An example of the arrangement of retreaded tyremarkings is shown in Annex E.

10 CRITERION FOR CONFORMITY

For the purpose of ascertaining conformity of the tyres tothis standard, the scale of sampling and criterion forconformity to the test requirements shall be mutuallyagreed to between the manufacturer and the purchaser.

11 BIS CERTIFICATION MARKING

The product may aIso be marked with the Standard Mark.

11.1 The use of the Standard Mark is governed by theprovisions of the Bureau of Indian Standards Act, 1986and the Rules and Regulations made thereunder. Thedetails of conditions under which the licence for the useof the Standard Mark may be granted to manufacturersor producers may be obtained from the Bureau of IndianStandards.

IS 15709:2006

ANNEX A(Ckmses 4.6.4 and 5.1)

METHOD OF MEASURING PNEUMATIC TYRES

A-1 PREPARING THE TYRE

A-1.l The tyre shall be mounted-on the test rim specifiedby the retreader and inflated to the pressure of 3 to 3.5bar.

A-1.2 The tyre pressure shall be adjusted as follows:

a) For standard bias-belted tyres for 1.7 bar;

b) For diagonal (bias-ply) tyres (see Table 4);

c) For standard radial tyres for 1.8 bar; and

d) For reinforced tyres for 2.3 bar.

A-2 MEASURING PROCEDURE

A-2.1 The tyre, mounted on its rim, shall be conditionedat the ambient room temperature for not less than 24 h.

A-2.2 The tyre pressure shall be readjusted to the levelspecified in B-1.2,

Table 4 Pressure for Speed Symbol[Clause A-1.2 (b)]

IT=iFFl“y: ‘:N

Lw__LldA-2.3 The overall width shall be measured at six equallyspaced points around the tyre, taking account of thethickness of any protective ribs or bands. The highestreading obtained shall be taken as the overall width.

A-2.4 The outer diameter shall be calculated from ameasurement of the maximum circumference of theinflated tyre.

ANNEX B(Clause 6.1)

PROCEDURE FOR LOAD/SPEED PERFORMANCE TEST

B-1 PREPARING THE TYRE

B-1:1 Mount a retreaded tyre on the test rim specified bythe retreader.

B-1.2 Inflate the tyre to the appropriate pressure asgiven (in bar) in Table 5.

B-1.3 The retreading production unit may request,giving reasons, the use of a test inflation pressure differentfrom those given in B-1.2. In this case the tyre shall beinflated to the requested pressure.

B-1.4 Condition the tyre and wheel assembly at test-roomtemperature for not less than 3 h.

B-1 .-5 Readjust the tyre pressure to that specifiedin B-1.2 or B-1.3.

B-2 TEST PROCEDURE

B-2.1 Mount the tyre and wheel assembly on a test axleand press it against the outer face of a smooth surfacedpower driven test drum either 1,70 m + lpercent or2.00 m +1percent diameter.

B-2.2 Apply to the test axle a load equal to 80 percent ofi

a)

b)

B-2.3

Maximum load rating corresponding to the LoadIndex for tyres with speedsymbols L to H inclusive,and

Maximum load rating associated with a maximumspeed of 240 krrdh for tyres of speed symbol ‘V’(see 3.31.2),

Throughout the test the tyre pressure must not becorrected and the test load must be kept constant.

10

IS 15709:2006

Table 5 Inflation Pressure(Clauses 6.1 and B-1 .2)

.SI Speed Category Diagonal (Bias-Ply) Tyres Radial Tyres Bias-Belted Tyres

No.Ply-rating Standard Reinforced Standard

4 Ply 6 ply 8 pty(1) (2) (3) (4) (5) (6) (7) (8)

i) L, M, N 2.3 2.7 3.0 2.4 —

ii) P, Q, R, S 2.6 3.0 3.3 2.6 3.0 “2.6

iii) T, U, H 2.8 3.2 3.5 2.8 3.2 2.8

iv) v 3.0 3.4 3.7 3.0 3.4 —

B-2.4 During the test the temperature in the test room mustbe maintained between 20° and 40”C unless the tyre ~,manufacturer or retreader agrees to a higher temperature.

B-2.5 The endurance test programme shall be cairied out d)

without interruption and shall -beas follows:

a)

b)

Time taken from zero speed to initial test speed for e)

10min; oInitial test speed: prescribed maximum speed forthe tyre concerned, less 40 kmib in the case of atest drum of diameter 1.70 m * lpercent or less30 km/h in the case of a test drum of diameter

2.00 m + 1percent.

Successive speed increments: 10 Ian/h up to themaximum test speed;

Duration of test at each speed step except the lastfor 10 rein;

Duration of test at last speed step for 20 rein; and

Maximum test speed: prescribed maximum speedfor the tyre concerned, less 10 kmih in the case of atest drum of 1.70 m + l-percent diameter or theprescribed maximum speed in the case of a testdrum of 2.00* 1percent diameter.

ANNEX C(Ckwe 7)

ENDURANCE TEST

C-1 APPARATUS the test drum at the initial (stage 1) test load, followed

The test wheel shall be a flat-smooth-faced wheel having by the test loads stage 2 and stage 3, as those specified

diameter of 1.7 m t 1 percent. The surface width of the in Table 6.

wheel shall be more than the loaded tyre tread width. Theair surrounding the tyre during the test shall be at atemperature of 20 to 40”C, or at a higher temperature, ifacceptable to the tyre manufacturer.

C-2 PREPARATION OF TYRE FOR THE TEST

Condition the inflated tyre/rim-wheel assembly in anambient atmosphere 20 to 40°C or higher, if acceptable tothe tyre manufacturer for a minimum period of 3 h.Readjust if necessary, the tyre pressure to the originalinflation pressure, immediately before the test.

C-3 TEST PROCEDURE

Mount the conditioned tyre/rim-wheel assembly on testmachine axle and press the tyre tread against the face of

Table 6 Endurance Test Parameters(Clause 7.1 and C-3)

SI Test Load Maximum Load Capability xNo. Percentage of Maximum Load(1) 5) (3)

Test Speed km/h 81

Test stage Test period Percentage of MaximumRated load

i) 1 4 85

ii) 2 6 90

iii) 3 24 I00

NOTE — Test inflation pressure 180 kPa.

11’

IS 15709:2006

ANNEX D(Ckmse 8. 1)

TYRE STRENGTH TEST (PLU!GER TEST)

D-1 APPARATUS

The equipment consists of a cylindrical steelplunger, having a hemispherical end of a diameter and adevice to force the plunger rod into a tyre at the rate50 ● 1.5 mm/min.

D-2 PREPARATION OF TYRE FOR THE TEST

The tyre with a tube shall be mounted and inflated on atest rim of the recommended size and shall be conditionedat approximately the temperature of the room in whichthe test is to be conducted for at least 3 h after which thepressure shall be adjusted, if necessary, to the testinflation pressure.

D-3 TEST PROCEDURE

The plunger rod shall be forced into the tread of the tyre/wheel assembly mounted as described in D-2,perpendicularly over a tread element at the centreline ofthe tread, or as near as possible to avoiding penetrationinto a tread groove. The rate of travel of the plunger shallbe 50 * 1.5 mrn/min until the tyre breaks or the plunger isstopped by the rim (bottoming of the plunger against the

rim), in which case the tyre shall be deemed to have passedthe test regardless of energy value. Measurement of forceand penetration at break (or bottoming against the rim)shall be made at 5 points nearly equally spaced aroundthe tyre circumference. The arithmetic mean of energyabsorbed shall be calculated from the five energy valuesobtained at the break, using the formula given in D-4.

D-4 FORMULA FOR CALCULATING THEBREAKING ENERGY

~= Fxp x103

2

where

W= energy at break (or bottoming), in J (Joule);

F = force at break (or bottoming), in N; and

P = penetration at break (or bottoming), in mm.

D-5 As an option, for purpose of conformity, if the plungerenergy measurements meet or exceed the minimum valuespecified, it is not necessary to continue penetration ofthe plunger to break the tyre.

Table 7 Static IWeakhtg Energy for Passenger Car ~res (Diagonal Ply)(Clause 8.1)

s! Tyre Size Ply Plunger Intlation Minimum Breaking EnergyNo. Rating Diameter Pressure f \

mm kPa Rayon NykrnJ (kg-cm) J (kg-cm)

(1) (2) (3) (4) (5) (6) (7)

i) Up to 6.00 4 19+ 0.2 165 113(1 152) “181(1 845)

(Nominal section) 6 19* (),2 195 169 (1 723) 271 (2 763)

ii) Above 6.00 4 19+ 0,2 195 186 (1 896) 294 (2 998)

(Nominal section) 6 19* 0.2 195 280 (2 852) 441 (4 497)

Including F78- 15 8 19+0.2 220 373 (3 802) 588 (5 996)

NOTES1 Recommended rim sizes shall be used forthe breaking energy test.2 ForF78-154PR breaking energy test, inflation pressure will be 170 I&a.

IS 15709:2006

Table 8 Static Ereaking Energy for Passenger Car Tyres (Radial Ply)(Clause 8.1)

SI Tyre Size Plunger Inflation Minimum Breaking EnergyNo. Nominal Section Diameter Pressure J (kg-cm)

Width mm kPa(1) (2) (3) (4) (5)

O Under 160 19* 1.6 180+5 220 (2 245)

ii) I60 or more 19* 1,6 180+5 295 (3 010)

ANNEX E(Clause 9,5)

ARRANGEMENT OF RETREADED TYRE MARKINGS

E-1 MARKINGS OF RETREADED PNEUMATICTYRES

1— — — Lb 185/70 R14 89T b

T––T1— il —

lhbeless: c M+S -C C Mar04 or 2504

TTT

Retread d

T

b = 6 mm, A4in

c = 4 mm, A4in

d= 3 mm, A4in

E-1.l

a)

b)

c)

d)

e)

These .markings define a retreaded tyre:

Nominal section width of 185;

Nominal aspect ratio of 70;

Radial-ply structure ( R);

Nominal rim diameter of code 14;

Service description ‘89T’ indicating a load capacity

of 580 kg corresponding to a load index of ’89’and a maximum speed capability of 190 “km/hcorresponding to a speed symbol ‘T’;

f) For fitting without an inner tube (’tubeless’) of snowtype (M+S); and

g) Retreaded month and year code that is in the monthof March of the year 2004 or in the weeks 25 ofthe year 2004.

E-1.2 The positioning and order of the markingsconstituting the tyre designation shall be as follows:

a)

b)

c)

d)

e)

f)

Size designation comprising the nominal sectionwidth, the nominal aspect ratio, the type-of-structure symbol (where applicable) and thenominal rim diameter-shall be grouped as shownjnthe above exampla 185/70 R14;

Service description comprising the load index andthe speed symbol shall be placed near;

the size designation. It may either precede the sizedesignation or follow it or be placed above;

or below it;

Symbols tubeless, reinforced and ‘M+ S’ maybeat a distance from the size designation; and

The word retread may be at a distance from thesize designation,

13

Bureau of Indian Standards

BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goods andattending to connected matters in the country.

Copyright.

BIS has the copyright of all its publications. No part of these publications may be reproduced in any formwithout the prior permission in writing of BIS. This does not preclude the free use, in the course of implementingthe standard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating tocopyright be addressed to the Director (Publications), BIS.

Review of”Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewedperiodically; a standard along with amendments is reaffirmed when such review indicates that no changes areneeded; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standardsshould ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of‘BIS Catalogue’ and’ Standards: Monthly Additions’.

This Indian Standard has been developed from Dot: No. TED 7 (468).

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

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