Pneumatic tyres for commercial vehicles and their trailers · Compulsory Specification for Pneumatic tyres for commercial vehicles and their trailers Published by Government Notice

Compulsory Specification for

Pneumatic tyres for commercial vehicles and theirtrailers

Published by Government Notice R1125 (Government Gazette 22822)of 16 November 2001

ICS 83.160.10VC 8059

Blank

1

SCHEDULE

COMPULSORY SPECIFICATION FOR PNEUMATIC TYRESFOR COMMERCIAL VEHICLES AND THEIR TRAILERS

1 Scope

1.1 This compulsory specification is based on ECE Regulation No. 54 of 21 March 1997, Uniformprovisions concerning the approval of pneumatic tyres for commercial vehicles and their trailers.

1.2 It covers new pneumatic tyres primarily designed for use by all road vehicles. It does not, however,apply to

a) new tyres for private (passenger) cars and their trailers,

b) tyres of a speed category below 80 km/h, or

c) tyres designed for cycles and motor cycles.

1.3 Homologation shall comprise the confirmation by the South African Bureau of Standards (SABS)that the local manufacturer or importer has provided the SABS with the following specific evidence inrespect of the commodity covered by this compulsory specification:

a) a summary of evidence showing that all relevant tests have been conducted with successful resultsunder appropriate controls in respect of the size or type of the commodity;

b) sufficient data to enable each size and type to be identified and related to (a) above;

c) relevant samples for the conducting of whatever tests and inspections are considered appropriateby the SABS, to verify any or all of the evidence provided;

d) details of the quality management system applied by the manufacturer; and

e) agreement by the manufacturing source to permit conformity of production audits to be carried outby the SABS or its appointed agent at the relevant manufacturing, assembling and testing facilities.

The SABS may issue such confirmation, on application, in respect of new sizes or types, provided thatsuch confirmation may not be used for the purpose of advertising or to imply that all units of thecommodity necessarily or consequently comply with the requirements of this compulsory specification.

2 Definitions

For the purposes of this specification, the following definitions apply:

2.1beadpart of a pneumatic tyre which is of such shape and structure as to fit the rim and hold the tyre on therim (see figure 1)

2

Figure 1 — Cross-section of a pneumatic tyre

2.2carcasspart of a pneumatic tyre other than the tread and the rubber sidewalls that, when inflated, bears theload (see figure 1)

2.3chunkingbreaking away of pieces of rubber from the tread

2.4cordstrands forming the fabric of the plies in the pneumatic tyre (see figure 1)

2.5cord separationparting of the cords from their rubber coating

2.6load capacity indexload index numbernumber that indicates the load a tyre can carry in single or in single and dual operation at the speedcorresponding to the associated speed category and when operated in conformity with the require-ments governing utilization as specified by the manufacturer

NOTE 1 A type of pneumatic tyre can have either one or two sets of load capacity indices depending on whether or notthe provisions of 3.2.5 are applied.

NOTE 2 The list of load capacity indices and their corresponding loads is given in annex A.

3

2.7lower sidewallarea included between the line of maximum section width of the tyre and the area designed to becovered by the rim flange (see figure 1)

2.8measuring rimrim on which a tyre is fitted for dimensional measurements

2.9nominal aspect ratioRaone hundred times the number obtained by dividing the number expressing the section height (H) bythe number expressing the nominal section width (S1), both dimensions expressed in the same units

2.10nominal rim diameterddiameter of the rim on which a tyre is designed to be mounted (see figure 1)

2.11outer diameterDoverall diameter of an inflated new pneumatic tyre (see figure 1)

2.12overall widthlinear distance between the outsides of the sidewalls of an inflated pneumatic tyre, including labelling(marking), decoration and protective bands or ribs (see figure 1)

2.13plylayer of rubber-coated parallel cords (see figure 1)

2.14ply separationparting of adjacent plies

2.15rimsupport for a tyre and tube assembly, or for a tubeless tyre, on which the tyre beads are seated (seefigure 1)

2.16section heightHdistance equal to half the difference between the outer diameter of the tyre and the nominal rimdiameter (see figure 1)

2.17section widthSlinear distance between the outsides of the sidewalls of an inflated pneumatic tyre, excluding elevationsdue to labelling (marking), decoration or protective bands or ribs (see figure 1)

2.18sidewallpart of a pneumatic tyre between the tread and the area designed to be covered by the rim flange (seefigure 1)

4

2.19snow tyretyre whose tread pattern and structure are primarily designed to ensure in mud and in fresh or meltingsnow a performance better than that of an ordinary (road type) tyre

NOTE The tread pattern of a snow tyre generally consists of groove (rib) or solid block elements (or both), more widelyspaced than on an ordinary (road type) tyre.

2.20speed categorymaximum speed which the tyre can sustain, expressed by a speed category symbol (see table 1)

Table 1 — Tyre speed category

1 2

Speed categorysymbol

Maximum speedkm/h

FGJ

8090

100

KLM

110120130

NPQ

140150160

RST

170180190

UH

200210

NOTE For consistency, these symbolsand speeds are the same as those forpassenger cars (as in ECE RegulationNo. 30). They should not be taken toindicate the speeds at which commercialvehicles fitted with such tyres may beoperated on the roads.

2.21structuretechnical characteristics of a pneumatic tyre's carcass

2.21.1diagonalbias-plypneumatic tyre structure in which the ply cords extend to the beads and are laid at alternate anglessubstantially less than 90° to the centre line of the tread

2.21.2radial-plypneumatic tyre structure in which the ply cords extend to the beads and are laid substantially at 90° tothe centre line of the tread, the carcass being stabilized by an essentially inextensible circumferentialbelt

2.22table of load capacity variation with speedtable B.1 showing the variation of the load capacity with speed for different speed categories/loadindices

NOTE The load variations do not apply in the case of the additional load capacity symbol and speed category obtainedwhen the provisions of 3.2.5 are applied.

5

2.23test rimrim on which a tyre is fitted for load/speed/endurance testing

2.24theoretical rimrim whose width would be equal to x times the nominal section width of a tyre

NOTE The value of x is specified by the manufacturer of the tyre.

2.25treadpart of a pneumatic tyre which comes into contact with the ground, protects the carcass againstmechanical damage and contributes to ground adhesion (see figure 1)

2.26tread groovespace between two adjacent ribs or blocks in the tread pattern (or both) (see figure 1)

2.27tread separationpulling away of the tread from the carcass

2.28type of pneumatic tyrecategory of pneumatic tyres which are similar in such essential respects as:

a) manufacturer's name or trademark;

b) tyre-size designation (see 2.29);

c) category of use (normal: normal-road-use tyres; special-use tyres, e.g. snow tyres, tyres for mixeduse (both on and off the road) or at restricted speed (or both));

d) structure (diagonal (bias-ply); radial) (see 2.21);

e) speed category (see 2.20);

f) load capacity index (see 2.6); and

g) tyre cross-section.

2.29tyre-size designationdesignation showing the following:

a) The nominal section width (S1). This width is expressed in millimetres, except in the case of thetypes of tyre for which the size designation is shown in the first column of the tables in annex C. Thenominal section width is expressed in numeric code.

b) The nominal aspect ratio, except in the case of certain types of tyre for which the size designationis shown in the first column of the tables in annex C.

c) A conventional number "d " (the "d " symbol) denoting the nominal rim diameter expressed either incodes (numbers below 100) or millimetres (numbers above 100). Numbers corresponding to bothtypes of measurement may be used together in the designation. The values of the "d " symbolsexpressed in millimetres are shown in table 2.

6

Table 2 — Nominal rim diameter

1 2

Nominal rim diametercode ("d" symbol)

Value of the "d" symbolmm

89

1011121314

203229254279305330356

1516171819

381406432457482

2021222425

508533559610635

14.516.517.519.520.522.524.5

368419445495521572622

3 Requirements

3.1 Dimensions of tyres

3.1.1 Section width of a tyre

3.1.1.1 The section width (S) shall be calculated using the following formula:

S = S1 + K (A S A1)

where

S is the section width, in millimetres, and measured on the measuring rim;

S1 is the nominal section width, in millimetres, as shown on the sidewall of the tyre in the sizedesignation of the tyre as described;

A is the width of the measuring rim, in millimetres, as shown by the manufacturer in thedescriptive note;

A1 is the width of the theoretical rim, in millimetres.

A1 shall be taken to equal S1 multiplied by the factor x, as specified by the manufacturer, and K shallbe taken to equal 0,4.

3.1.1.2 For the existing types of tyre whose size designation is given in the first column of the tablesin annex C, the section width shall be that given opposite the tyre-size designation in these tables.

7

3.1.2 Outer diameter of a tyre

3.1.2.1 The outer diameter of a tyre shall be calculated using the following formula:

D = d + 2H

where

D is the outer diameter, in millimetres;

d is the conventional number defined in 2.29(c), in millimetres;

H is the nominal section height, in millimetres, equal to 0,01 S1 × Ra;

S1 is the nominal section width, in millimetres;

Ra is the nominal aspect ratio,

with d, H, S1 and Ra as shown on the sidewall of the tyre in conformity with the requirements of 5.3.

3.1.2.2 However, for the existing types of tyre whose size designation is given in the first column of thetables in annex C, the outer diameter shall be that given opposite the size designation in these tables.

3.1.3 Method of measuring pneumatic tyres

The dimensions of pneumatic tyres shall be measured by the procedure described in annex D.

3.1.4 Tyre section width specifications

3.1.4.1 The overall width of a tyre may be less than the section width(s) determined in accordance with3.1.1.

3.1.4.2 The section width may exceed that value by the following percentages:

a) for radial-ply tyres: 4 %; and

b) for diagonal (bias-ply) tyres: 6 %.

3.1.4.3 For tyres with a section width exceeding 305 mm intended for dual mounting (twinning), thenominal value shall not be exceeded by more than

a) 2 % for radial-ply tyres, or

b) 4 % for diagonal (bias-ply) tyres.

3.1.5 Tyre outer diameter specifications

The outer diameter of a tyre shall not be outside the values Dmin and Dmax obtained from the followingformulae:

Dmin = d + 2H × a

Dmax = d + 2H × b

where,

for sizes listed in annex C:

H = 0,5 (D S d )

NOTE For definition of the variables see 3.1.2.1.

8

where,

for other sizes not listed in annex C:

H and d are as defined in 3.1.2.1

where,

values for coefficients a and b are respectively

a = 0,97

for ordinary (road type) tyres,

b = 1,04 (for radial tyres), or

b = 1,07 (for diagonal tyres); and

for special-use tyres,

b = 1,06 (for radial tyres), or

b = 1,09 (for diagonal tyres)

and, where

for snow tyres the overall diameter (Dmax) established in conformity with the above may beexceeded by 1 %.

3.2 Load/speed performance test

3.2.1 Each type of pneumatic tyre shall undergo at least one load/speed performance test asdescribed in annex E.

3.2.2 A tyre that, after undergoing the load/speed performance test, does not exhibit any tread sepa-ration, ply separation, cord separation, chunking or broken cords, shall be deemed to have passed thetest.

3.2.3 The outer diameter of the tyre, measured six hours after the load/speed performance test, shallnot differ by more than ± 3,5 % from the outer diameter as measured before the test.

3.2.4 Where application is made for the testing of a type of pneumatic tyre for the load/speedcombinations given in table B.1, the performance test prescribed in 3.2.1 need not be carried out forload and speed values other than the nominal values.

3.2.5 Where application is made for the testing of a type of pneumatic tyre which has a load/speedcombination in addition to one that is subject to the variation of load with speed given in table B.1, theperformance test prescribed in 3.2.1 shall also be carried out on a second tyre of the same type at theadditional load/speed combination.

4 Equivalent requirements

The requirements of this specification may be deemed to have been met if a tyre complies with therequirements of ECE Regulation No. 54 of 21 March 1997, Uniform provisions concerning the approvalof pneumatic tyres for commercial vehicles and their trailers.

9

5 Marking

5.1 Pneumatic tyres shall bear on both sidewalls in the case of symmetrical tyres and at least on theouter sidewall in the case of asymmetrical tyres the following:

a) the manufacturer's trade name or trademark;

b) the tyre-size designation as defined in 2.29;

c) an indication of the structure

1) on diagonal (bias-ply) tyres, no marking, or the letter "D" placed in front of the rim-diametermarking,

2) on radial-ply tyres the letter "R" placed in front of the rim diameter marking, and optionally, theword "RADIAL",

d) the speed category symbol (or symbols);

1) an indication of the tyre's nominal speed category by means of the symbol shown in table 1,

2) an indication of a second speed category in cases where 3.2.5 is applicable;

e) the inscription M+S or M.S or M&S in the case of a snow tyre;

f) the load capacity index as defined in 2.6;

g) the word "TUBELESS" if the tyre is designed for use without an inner tube;

h) the date of manufacture in the form of a group of four digits, the first two showing the week and thelast two the year of manufacture. This marking may be placed on one sidewall only;

i) in the case of tyres that can be regrooved, the symbol " " at least 20 mm in diameter, or the

word 'REGROOVABLE", moulded into or onto each sidewall.

j) an indication, by the pressure index, of the inflation pressure to be adopted for the load/speedendurance tests, as explained in table E.2. This marking may be placed on one sidewall only.

k) an identification of the tyre rim fitment configuration when it differs from the standard configurationand when it is not already expressed by the symbol "d " denoting the nominal rim-diameter code.

5.2 Annex F gives an example of the arrangement of the tyre markings.

5.3 The markings referred to in 5.1 shall be moulded onto or into the tyres. They shall be clearlylegible and, except for the marking referred to in 5.1(a), shall be located on at least one lower sidewall.

10

Annex A(normative)

Load capacity indices

Table A.1 — Load capacity indices

1 2 1 2 1 2 1 2

Lia kgb Li kg Li kg Li kg

606162

250257265

969798

710730750

132133134

2 0002 0602 120

168169170

5 6005 8006 000

636465

272280290

99100101

775800825

135136137

2 1802 2402 300

171172173

6 1506 3006 500

666768

300307315

102103104

850875900

138139140

2 3602 4302 500

174175176

6 7006 9007 100

697071

325335345

105106107

925950975

141142143

2 5752 6502 725

177178179

7 3007 5007 750

727374

355365375

108109110

1 0001 0301 060

144145146

2 8002 9003 000

180181182

8 0008 2508 500

757677

387400412

111112113

1 0901 1201 150

147148149

3 0753 1503 250

183184185

8 7509 0009 250

787980

425437450

114115116

1 1801 2151 250

150151152

3 3503 4503 550

186187188

9 5009 750

10 000

818283

462475487

117118119

1 2851 3201 360

153154155

3 6503 7503 875

189190191

10 30010 60010 900

848586

500515530

120121122

1 4001 4501 500

156157158

4 0004 1254 250

192193194

11 20011 50011 800

878889

545560580

123124125

1 5501 6001 650

159160161

4 3754 5004 625

195196197

12 15012 50012 850

909192

600615630

126127128

1 7001 7501 800

162163164

4 7504 8755 000

198199200

13 20013 60014 000

939495

650670690

129130131

1 8501 9001 950

165166167

5 1505 3005 450

a Li = Load capacity maximum index.

b kg = Corresponding maximum mass that the tyre is rated to carry.

11

Annex B(normative)

Load capacity variation with speed

Table B.1 — Variation of load capacity with speed — Tyresfor commercial vehicles — Radial and diagonal

1 2 3 4 5 6 7 8 9 10 11Variation of load capacity

%

Speedkm/h

All load indices Load indices> 122a

Load indices< 121a

Speed category symbol Speed categorysymbol Speed category symbol

F G J K L M L M N Pb

0 +150 +150 +150 +150 +150 +150 +110 +110 +110 +1105 +110 +110 +110 +110 +110 +110 +90 +90 +90 +90

10 +80 +80 +80 +80 +80 +80 +75 +75 +75 +7515 +65 +65 +65 +65 +65 +65 +60 +60 +60 +6020 +50 +50 +50 +50 +50 +50 +50 +50 +50 +5025 +35 +35 +35 +35 +35 +35 +42 +42 +42 +4230 +25 +25 +25 +25 +25 +25 +35 +35 +35 +3535 +19 +19 +19 +19 +19 +19 +29 +29 +29 +2940 +15 +15 +15 +15 +15 +15 +25 +25 +25 +2545 +13 +13 +13 +13 +13 +13 +22 +22 +22 +2250 +12 +12 +12 +12 +12 +12 +20 +20 +20 +2055 +11 +11 +11 +11 +11 +11 +17,5 +17,5 +17,5 +17,560 +10 +10 +10 +10 +10 +10 +15,0 +15,0 +15,0 +15,065 +7,5 +8,5 +8,5 +8,5 +8,5 +8,5 +13,5 +13,5 +13,5 +13,570 +5,0 +7,0 +7,0 +7,0 +7,0 +7,0 +12,5 +12,5 +12,5 +12,575 +2,5 +5,5 +5,5 +5,5 +5,5 +5,5 +11,0 +11,0 +11,0 +11,080 0 +4,0 +4,0 +4,0 +4,0 +4,0 +10,0 +10,0 +10,0 +10,085 S3 +2,0 +3,0 +3,0 +3,0 +3,0 +8,5 +8,5 +8,5 +8,590 S6 0 +2,0 +2,0 +2,0 +2,0 +7,5 +7,5 +7,5 +7,595 S10 S2,5 +1,0 +1,0 +1,0 +1,0 +6,5 +6,5 +6,5 +6,5

100 S15 S5 0 0 0 0 +5,0 +5,0 +5,0 +5,0105 S8 S2 0 0 0 +3,75 +3,75 +3,75 +3,75110 S13 S4 0 0 0 +2,5 +2,5 +2,5 +2,5115 S7 S3 0 0 +1,25 +1,25 +1,25 +1,25120 S12 S7 0 0 0 0 0 0125 0 S2,5 0 0 0130 0 S5,0 0 0 0135 S7,5 S2,5 0 0140 S10 S5 0 0145 S7,5 S2,5 0150 S10,0 S5,0 0155 S7,5 S2,5160 S10,0 S5,0

a The load capacity indices refer to a single operation.b Load variations are not allowed for speeds above 160 km/h. For speed category symbols "Q" and above, the speedcategory corresponding to the speed category symbol (see 2.20) specifies the maximum speed permitted for the tyre.

12

Annex C(normative)

Tyre-size designation and dimensions

C.1 European tyres

Table C.1 — Code designated tyres mounted on 5° tapered rimsor flat-base rims — Radial and diagonal

1 2 3 4 5 6 7

Size designationa Measuring rimwidth code

Nominal rimdiameter d

Outer diameter Dmm

Section width Smm

mm Radial Diagonal Radial Diagonal

Standard series

4.00 R 8b

4.00 R 10b

4.00 R 12b

2.503.003.00

203254305

414466517

414466517

107108108

107108108

4.50 R 8b

4.50 R 10b

4.50 R 12b

3.503.503.50

203254305

439490545

439490545

125125125

125125128

5.00 R 8b

5.00 R 10b

5.00 R 12b

3.003.503.50

203254305

467516568

467516568

132134134

132134137

6.00 R 96.00 R 14 C6.00 R 16b

4.004.504.50

229356406

540626728

540625730

160158170

160158170

6.50 R 106.50 R 14 C6.50 R 16b

6.50 R 20b

5.005.004.505.00

254356406508

588640742860

588650748

–

177170176181

177172176

–

7.00 R 127.00 R 14 C7.00 R 15b

5.005.005.00

305356381

672650746

672668752

192180197

192182198

7.00 R 16 C7.00 R 167.00 R 20

5.505.505.50

406406508

778784892

778774898

198198198

198198198

7.50 R 107.50 R 14 C7.50 R 15b

5.505.506.00

254356381

645686772

645692772

207195212

201192212

7.50 R 16b

7.50 R 17b

7.50 R 20

6.006.006.00

406432508

802852928

806852928

210210210

210210213

8.25 R 158.25 R 168.25 R 178.25 R 20

6.506.506.506.50

381406432508

836860886962

836860895970

230230230230

234234234234

9.00 R 159.00 R 16b

9.00 R 20

6.006.507.00

381406508

840912

1 018

840900

1 012

249246258

249252256

10.00 R 1510.00 R 2010.00 R 22

7.507.507.50

381508559

9181 0521 102

9181 0501 102

275275275

275275275

a Tyres in diagonal construction are identified by a hyphen in place of the letter "R" (e.g. 5.00-8).

b The tyre-size designation may be supplemented with the letter "C" (e.g. 6.00-16 C).

13

Table C.1 (concluded )

1 2 3 4 5 6 7



Outer diameter Dmm

Section width Smm


11.00 R 1611.00 R 2011.00 R 2211.00 R 24

6.508.008.008.00

406508559610

9801 0821 1321 182

9521 0801 1301 180

279286286286

272291291291

12.00 R 2012.00 R 2212.00 R 24

8.508.508.50

508559610

1 1221 1741 226

1 1201 1741 220

313313313

312312312

13.00 R 2014.00 R 2014.00 R 2416.00 R 20

9.0010.0010.0013.00

508508610508

1 1761 2381 3401 370

1 1701 2381 3401 370

336370370446

342375375446

80 Series

12/80 R 2013/80 R 2014/80 R 20

8.509.00

10.00

508508508

1 0081 0481 090

–––

305316350

–––

14/80 R 2414.75/80 R 2015.5/80 R 20

10.0010.0010.00

610508508

1 1921 1241 158

–––

350370384

–––

Wide base tyres for multipurpose trucks

7.50 R 18 MPT10.5 R 18 MPT10.5 R 20 MPT

5.5099

457457508

885905955

276276

208270270

12.5 R 18 MPT12.5 R 20 MPT14.5 R 20 MPT14.5 R 24 MPT

11111111

457508508610

9901 0401 0951 195

330330362362

325325355355

a Tyres in diagonal construction are identified by a hyphen in place of the letter "R" (e.g. 5.00-8).

b The tyre-size designation may be supplemented with the letter "C" (e.g. 6.00-16 C).

14

Table C.2 — Code designated tyres mounted on 15° tapered rims — Radial

1 2 3 4 5

Size designation Measuring rimwidth code


mm

Outerdiameter D

mm

Sectionwidth S

mm

7 R 17.5a

7 R 19.58 R 17.5a

5.255.256.00

445495445

752800784

185185208

8 R 19.58 R 22.58.5 R 17.5

6.006.006.00

495572445

856936802

208208215

9 R 17.59 R 19.59 R 22.5

6.756.756.75

445495572

820894970

230230230

9.5 R 17.59.5 R 19.510 R 17.5

6.756.757.50

445495445

842916858

240240254

10 R 19.510 R 22.511 R 22.5

7.507.508.25

495572572

9361 0201 050

254254279

11 R 24.512 R 22.513 R 22.5

8.259.009.75

622572572

1 1001 0841 124

279300320

15 R 19.515 R 22.516.5 R 19.5

11.7511.7513.00

495572495

9981 0741 046

387387425

16.5 R 22.518 R 19.518 R 22.5

13.0014.0014.00

572495572

1 1221 0821 158

425457457

70 Series

10/70 R 22.511/70 R 22.512/70 R 22.513/70 R 22.5

7.508.259.009.75

572572572572

928962

1 0001 033

254279305330

a The tyre-size designation may be supplemented with the letter "C" (e.g. 7 R 17.5 C).

15

Table C.3 — Tyres for light commercial vehicles — Radial and diagonal

1 2 3 4 5 6 7



Outer diameter Dmm

Section width Smm


Metric designated

145 R 10 C145 R 12 C145 R 13 C145 R 14 C145 R 15 C

4.004.004.004.004.00

254305330356381

492542566590616

–––––

147147147147147

–––––

155 R 12 C155 R 13 C155 R 14 C

4.504.504.50

305330356

550578604

–––

157157157

–––

165 R 13 C165 R 14 C165 R 15 C

4.504.504.50

330356381

596622646

–––

167167167

–––

175 R 13 C175 R 14 C175 R 16 C

5.005.005.00

330356406

608634684

–––

178178178

–––

185 R 13 C185 R 14 C185 R 15 C185 R 16 C

5.505.505.505.50

330356381406

624650674700

––––

188188188188

––––

195 R 14 C195 R 15 C195 R 16 C

5.505.505.50

356381406

666690716

–––

198198198

–––

205 R 14 C205 R 15 C205 R 16 C

6.006.006.00

356381406

686710736

–––

208208208

–––

215 R 14 C215 R 15 C215 R 16 C245 R 16 C

6.006.006.007.00

356381406406

700724750798

–––

798

218218218248

–––

248

17 R 15 C17 R 380 C17 R 400 C19 R 400 C

5.005.00

150 mm150 mm

381381400400

678678698728

––––

178178186200

––––

Code designated

5.60 R 12 C6.40 R 13 C6.70 R 13 C6.70 R 14 C6.70 R 15 C

4.005.005.005.005.00

305330330356381

570648660688712

572640662688714

150172180180180

148172180180180

a Tyres in diagonal construction are identified by a hyphen in place of the letter "R" (e.g. 145-10 C).

16

Table C.4 — Tyres for special applications — Radial and diagonal

1 2 3 4 5



mm

Outerdiameter D

mm

Sectionwidth S

mm

Code designated

15 × 4 1/2-816 × 6-818 × 7

3.254.334.33

203203203

385425462

122152173

18 × 7-821 × 8-921 × 4

4.336.002.32

203229330

462535565

173200113

22 × 4 1/223 × 523 × 9-10

3.113.756.50

330330254

595635595

132155225

24 × 7.50-1325 × 627 × 8.50-14

6.003.757.00

330330356

597680674

191170218

27 × 10-1228 × 8.50-1528 × 9-15

8.007.007.00

305381381

690699707

255218216

29 × 9.50-1530 × 9.50-1531 × 10.50-15

7.507.508.50

381381381

724750775

240240268

31 × 11.50-1531 × 13.50-1531 × 15.50-15

9.0011.0012.00

381381381

775775775

290345390

32 × 11.50-5033 × 12.50-1535 × 12.50-15

9.0010.0010.00

381381381

801826877

290318318

37 × 12.50-1537 × 14.50-15

10.0012.00

381381

928928

318372

Metric designated

200-15250-15300-15

6.507.508.00

381381381

730735840

205250300

NOTE Tyres in radial construction are identified by the letter "R" in place of the hyphen" - " (e.g. 15 × 4 1/2 R 8).

17

C.2 United States tyres

Tolerances shown at the bottom of the tables below apply in place of those shown in 3.1.4.2 and 3.1.5.

Outer diameters are listed for the various categories of use: Normal, snow, special.

Table C.5 — Tyres for light commercial vehicles(LT tyres) — Radial and diagonal

1 2 3 4 5 6



Outer diameter Db

mmSectionwidth Sc

mm Normal Snow mm

6.00-16 LT6.50-16 LT6.70-16 LT

4.504.505.00

406406406

732755722

743767733

173182191

7.00-13 LT7.00-14 LT7.00-15 LT

5.005.005.50

330356381

647670752

658681763

187187202

7.00-16 LT7.10-15 LT7.50-15 LT

5.505.006.00

406381381

778738782

788749794

202199220

7.50-16 LT8.25-16 LT9.00-16 LT

6.006.506.50

406406406

808859890

819869903

220241257

G 78-15 LTH 78-15 LTL 78-15 LTL 78-16 LT

6.006.006.506.50

381381381406

711727749775

722739760786

212222236236

7-14.5 LTd

8-14.5 LTd

9-14.5 LTd

6.006.007.00

368368368

677707711

185203241

7-17.5 LT8-17.5 LT

5.255.25

445445

758788

769799

189199

a Tyres in radial construction are identified by the letter "R" in place of " - " (e.g. 6.00 R 16 LT).

b Coefficient "b" for the calculation of Dmax: 1.08.

c Overall width may exceed this value by up to +8 %.

d The suffix "MH" may replace "LT" in the tyre-size designation (e.g. 7-14.5 MH).

18

Table C.6 — Tyres for light commercial vehicles(high flotation tyres) — Radial and diagonal

1 2 3 4 5 6



Outer diameter Db

mmSectionwidth Sc

mm Normal Snow mm

9-15 LT10-15 LT11-15 LT

8.008.008.00

381381381

744773777

755783788

254264279

24 × 7.50-13 LT27 × 8.50-14 LT28 × 8.50-15 LT

677

330356381

597674699

604680705

191218218

29 × 9.50-15 LT30 × 9.50-15 LT31 × 10.50-15 LT

7.57.58.5

381381381

724750775

731756781

240240268

31 × 11.50-15 LT31 × 13.50-15 LT31 × 15.50-15 LT

91112

381381381

775775775

781781781

290345390

32 × 11.50-15 LT33 × 12.50-15 LT35 × 12.50-15 LT

91010

381381381

801826877

807832883

290318318

37 × 12.50-15 LT37 × 14.50-15 LT

1012

381381

928928

934934

318372

8.00-16.5 LT8.75-16.5 LT9.50-16.5 LT

6.006.756.75

419419419

720748776

730759787

203222241

10-16.5 LT12-16.5 LT

8.259.75

419419

762818

773831

264307

30 × 9.50-16.5 LT31 × 10.50-16.5 LT33 × 12.50-16.5 LT

7.508.259.75

419419419

750775826

761787838

240266315

37 × 12.50-16.5 LT37 × 14.50-16.5 LT

9.7511.25

419419

928928

939939

315365

a Tyres in radial construction are identified by the letter "R" in place of " - " (e.g. 24 × 7.50 R 13 LT).

b Coefficient "b" for the calculation of Dmax: 1.07.


19

Table C.7 — Code designated tyres mounted on 5° tapered rimsor flat-base rims — Radial and diagonal

1 2 3 4 5 6 7



Outer diameter Db

mm Sectionwidth ScNormal

Snowmm a b mm

6.50-207.00-15 TR7.00-18

55.55.5

508381457

878777853

893792868

184199199

7.00-207.50-15 TR7.50-17

5.566

508381432

904808859

919825876

199215215

7.50-187.50-208.25-15 TR

66

6.5

457508381

884935847 855

901952865

215215236

8.25-209.00-15 TR9.00-20

6.577

508381508

974891

1 019

982904

1 031

992911

1 038

236259259

10.00-15 TR10.00-2010.00-22

7.57.57.5

381508559

9271 0541 104

9401 0671 118

9461 0731 123

278278278

11.00-2011.00-2211.00-24

888

508559610

1 0851 1351 186

1 0991 1501 201

1 1041 1551 206

293293293

11.50-2012.00-2012.00-24

88.58.5

508508610

1 0851 1251 226

1 099 1 1041 1461 247

296315315

14.00-2014.00-24

1010

508610

1 2411 343

1 2661 368

375375

a Tyres in radial construction are identified by the letter "R" in place of " - " (e.g. 6.50 R 20).

b Coefficient "b" for the calculation of Dmax: 1.06.Category of use: Normal service tyres: (a) highway tread (b) heavy tread.


Table C.8 — Code designated tyres for special services — Diagonal

1 2 3 4 5 6



Outer diameter Da

mmSectionwidth Sb

mm a b mm

10.00-20 ML11.00-22 ML13.00-24 ML

7.589

508559610

1 0731 1551 302

1 0991 182

278293340

14.00-20 ML14.00-24 ML15-19.5 ML

1010

11.75

508610495

1 2661 3681 019

375375389

a Coefficient "b" for the calculation of Dmax: 1.06.Category of use: Special: (a) traction tread (b) heavy tread.

b Overall width may exceed this value by up to +8 %.

20

Table C.9 — Code designated tyres mountedon 15° tapered rims — Radial and diagonal

1 2 3 4 5 6 7



Outer diameter Db

mmSectionwidth ScNormal

Snowmm a b mm

8-19.58-22.59-22.5

6.006.006.75

495572572

859935974 982

876952992

203203229

10-22.511-22.511-24.5

7.508.258.25

572572622

1 0191 0541 104

1 0311 0671 118

1 0381 0731 123

254279279

12-22.512-24.512.5-22.512.5-24.5

9.009.009.009.00

572622572622

1 0851 1351 0851 135

1 0991 1501 0991 150

1 1041 1551 1041 155

300300302302

14-17.515-19.515-22.5

10.5011.7511.75

445495572

9071 0051 082

9211 0191 095

349 (-)389 (-)389 (-)

16.5-22.518-19.518-22.5

13.0014.0014.00

572495572

1 1281 0801 158

1 1441 0961 172

425 (-)457 (-)457 (-)

a Tyres in radial construction are identified by the letter "R" in place of " - " (e.g. 8 R 19.5).

b Coefficient "b" for the calculation of Dmax: 1.05.Category of use: Normal service tyres: (a) highway tread (b) heavy tread.

c Overall width may exceed this value by up to +6 %.(-) overall width may exceed this value by up to +5 %.

21

Annex D(normative)

Method of measuring pneumatic tyres

D.1 Mount the tyre on the measuring rim specified by the manufacturer and inflate it to a pressurespecified by the manufacturer.

D.2 Condition the tyre, mounted on its rim, at ambient room temperature for at least 24 h.

D.3 Readjust the pressure to the value specified in D.1.

D.4 Measure the overall width by calliper at six equally spaced points, taking the thickness of theprotective ribs or bands into account. The highest measurement so obtained is taken as the overallwidth.

D.5 Determine the outer diameter from the maximum circumference.

22

Annex E(normative)

Procedure for load/speed performance tests

E.1 Preparing the tyre

E.1.1 Mount a new tyre on the test rim specified by the manufacturer.

E.1.2 Use a new inner tube or combination of inner tube, valve and flap (as required), when testingtyres with inner tubes.

E.1.3 Inflate the tyre to the pressure corresponding to the pressure index (see table E.1) specifiedby the manufacturer.

E.1.4 Condition the tyre and wheel assembly at test room temperature for not less than 3 h.

E.1.5 Readjust the tyre pressure to that specified in E.1.3.

Table E.1 — Relation between the pressureindex and the units of pressure

1 2 3

Pressureindex (PSI) Bar kPa

202530

1,41,72,1

140170210

354045

2,42,83,1

240280310

505560

3,43,84,1

340380410

657075

4,54,85,2

450480520

808590

5,55,96,2

550590620

95100105

6,66,97,2

660690720

110115120

7,67,98,3

760790830

125130135

8,69,09,3

860900930

140145150

9,710,010,3

9701 0001 030

23

E.2 Test procedure

E.2.1 Mount the tyre and wheel assembly on a test axle and press it against the outer face of asmooth power-driven test drum 1,70 m ± 1 % in diameter having a surface at least as wide as the tyretread.

E.2.2 Apply to the test axle a series of test loads expressed in a percentage of the load indicated inannex A, opposite the load index engraved on the sidewall of the tyre, and in accordance with the testprogramme in E.3. Where the tyre has load capacity indices for both single and twinned utilization, thereference load for single utilization shall be taken as the basis for the test loads.

E.2.2.1 In the case of a tyre with a load capacity index 121 or less and a speed category above P, testprocedures are as specified in E.3.

E.2.2.2 The endurance test programme is given in table E.2.

Table E.2 — Endurance test programme

1 2 3 4 5 6 7 8 9

Load index Tyre speedcategory

Test drum speedrpm

Load placed on the wheel as a percentage ofthe load corresponding to the load index

Radial-ply Diagonal(bias-ply) Duration of test

min–1 min–1 4 h 6 h 7 h 16 h 24 h

122 or more F 100 100

G 125 100

J 150 125

K 175 150

L 200 –

M 225 – 66 % 84 % 101 %

121 or less F 100 100

G 125 125

J 150 150

K 175 175

L 200 175 70 % 88 % 106 %

M 250 200 75 % 97 % 114 %

N 275 – 75 % 97 % 114 %

P 300 – 75 % 97 % 114 %

NOTE 1 Special-use tyres (see 2.28(c)) should be tested at a speed equal to 85 % of the speed describedfor equivalent normal tyres.

NOTE 2 Tyres with a load index of 122 or more of speed categories above M are not yet produced.

E.2.3 The tyre pressure shall not be corrected throughout the test and the test load shall be keptconstant throughout each of the three test stages.

E.2.4 During the test the temperature in the test room shall be maintained at between 20 °C and30 °C or at a higher temperature if the manufacturer so agrees.

E.2.5 The endurance test programme shall be carried out without interruption.

24

E.3 Load/speed test programme for tyre with a load capacity index 121or less and a speed category Q and above

E.3.1 The load placed on the wheel, as a percentage of the load corresponding to the load index, isas follows:

a) 90 % when tested on a test drum 1,70 m ± 1 % in diameter; and

b) 92 % when tested on a test drum 2,0 m ± 1 % in diameter.

E.3.2 The initial test speed shall be the speed corresponding to the speed category symbol less20 km/h, the time to reach the initial test speed shall be 10 min and the duration of the first step shallbe 10 min.

E.3.3 The second test speed shall be the speed corresponding to the speed category symbol less10 km/h and the duration of the second step shall be 10 min.

E.3.4 The final test speed shall be the speed corresponding to the speed category symbol and theduration of the final step shall be 30 min.

E.3.5 The total test duration shall be 1 h.

E.3.6 Check for compliance with the requirements in 3.2.

E.4 Equivalent test methods

If a method other than that described in E.2 is used, its equivalence shall be demonstrated.

25

Annex F(informative)

Arrangement of tyre markings

F.1 The following is an example of the markings to be borne by types of tyre placed on the marketafter the entry into force of this specification.

where the values for b, c and d are as shown in table F.1.

Table F.1 — Minimum dimensions of markings

1 2 3

Heightsymbol

Minimum height of markingsmm

Tyres of rim diameter < 20 or< 508 mm or of section width

< 235 mm or < 9

Tyres of rim diameter > 20 or> 508 mm or of section width

> 235 mm or > 9

b 6 9

c 4

d 6

F.2 These markings define a pneumatic tyre that

a) has a nominal section width of 250,

b) has a nominal aspect ratio of 70,

c) is of radial-ply structure (R),

d) has a nominal rim diameter of 508 mm, for which the symbol is 20,

e) has load capacities of 3 250 kg when single and 2 900 kg when twinned (dual), correspondingrespectively to the load indices 149 and 145 shown in annex A,

f) is classified in the nominal speed category J (reference speed 100 km/h),

g) is able to be used additionally in speed category L (reference speed 120 km/h) with load capacitiesof 3 000 kg when single and 2 725 kg when twinned (dual), corresponding respectively to the loadindices 146 and 143 shown in table A.1,

h) is capable of being fitted without an inner tube ("TUBELESS") or is of the "snow" type,

i) is manufactured during the twenty-fifth week of the year 2003, and

j) is required to be inflated to 620 kPa for load/speed endurance tests, for which the pressure symbolis 90 psi.

26

F.3 The positioning and order of the markings constituting the tyre-size designation shall be thefollowing:

a) the size designation comprising the nominal section width, the nominal aspect ratio, the type ofstructure symbol (where applicable) and the nominal rim diameter and shall be grouped as shownin the above example: 250/70 R 20;

b) the load index and the symbol of the speed category shall be placed together near the sizedesignation. They may either precede or follow it or be placed above or below it;

c) the symbols "TUBELESS" and "M+S" may be at a distance from the size designation symbol; and

d) if 3.2.5 applies, the additional load capacity index and speed category symbol shall be shown insidea circle near the nominal load capacity index and speed category symbol appearing on the tyresidewall.

Documents

Pneumatic tyres for commercial vehicles and their trailers · Compulsory Specification for Pneumatic tyres for commercial vehicles and their trailers Published by Government Notice