DRAFT UGANDA STANDARD ON PUBLIC REVIEW     DRAFT UGANDA 
STANDARD  
    DUS EAS 359 
First  Edition  
2015-mm-dd 
 
 Reference number 
  DUS EAS 359: 2004 
© UNBS 201 5 
  
Pneumatic tyres for light trucks  — Specification  
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWDUS EAS 359:20 04 
ii                © UNBS 2015 - All rights reserved 
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2015 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala 
Uganda 
Tel: 256 41 505 995 
Fax: 256 41 286 123 
E-mail: unbs@infocom.co.ug  
Web: www.unbs.go.ug  
 DRAFT UGANDA STANDARD ON PUBLIC REVIEW   DUS EAS 359:20 04 
© UNBS  2015 - All rights reserved                iii National foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of the Laws of Uganda, as amended.  UNBS is mandated to co-
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT Agreement of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
This Draft Uganda Standard, DUS EAS 359: 2004, Pneumatic tyres for light trucks  — Specification , is 
identi cal with  and has been reproduced from an East African  Standard , EAS 359: 2004 , Pneumatic tyres for 
light trucks  — Specification , and is being proposed for adoption  as a Uganda Standard.  
This standard cancels and replaces US 515:2004, Specification for new pneumatic tyres — Light trucks . 
This Uganda Standard, DUS EAS 359: 2004 , has been developed by the Transport and communication 
standards Technical Committee (UNBS/TC 8).  
Wherever the words, “ East African Standard" appear, they should be replaced by "Uganda Standard." 
 
  DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004 
ICS 83.160.10 
HS 4011.20; 
HS 4011.20.10 (radial) 
 HS 4011.20.90 (other) 
© EAC 2004                                                                                                      First Edition 2 004  
 
 
 
 
EAST AFRICAN STANDARD 
 
Pneumatic tyres for light trucks — Specification 
 
  
 
  
 
 
 
  
 
 
 
  
 
 
 
  
 
  
 
 
 
  
 
 
EAST AFRICAN COMMUNITY 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
ii                                                                                                © EAC 2004 — All rights reser ved  
 
Foreword 
 
Development of the East African Standards has been necessitated by the need for harmonizing 
requirements governing quality of products and services in East Africa. It is envisaged that through 
harmonized standardization, trade barriers which are encountered when goods and services are 
exchanged within the Community will be removed.  
In order to achieve this objective, the Partner States in the Community through their National Bureaux 
of Standards, have established an East African Standards Committee.  
The committee is composed of representatives of the National Standards Bodies in Partner States, 
together with the representatives from the private sectors and consumer organizations. Draft East 
African Standards are circulated to stakeholders through the National Standards Bodies in the Partner 
States. The comments received are discussed and incorporated before finalization of standards, in accordance with the procedures of the Community.  
East African Standards are subject to review, to keep pace with technological advances. Users of the 
East African Standards are therefore expected to ensure that they always have the latest versions of the standards they are implementing.  
 
© East African Community 2004 — All rights reserved
* 
East African Community  P O Box 1096  
Arusha  
Tanzania  Tel: 255 27 2504253/8 Fax: 255-27-2504481/2504255 
E-Mail: eac@eachq.org Web: www.each.int 
 
  
                                                
 
* © 2004 EAC — All rights of exploitation in any form and by any means reserved worldwide for EAC Partner States’ NSBs. 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                iii  
Introduction  
 
This East African Standardhas been prepared in order to give the necessary specifications and 
requirements for test of pneumatic tyres. It provides important information to be observed for 
improvement of motor vehicle safety in the country. 
 In reporting the results of a test made in accordance with this East African Standard, if the final value, 
observed or calculated is to be rounded off, it shall be done in accordance with EAS 124. 
 
In the preparation of this East African Standard, assistance has been derived from the following 
documents: 
 
BS AU 50-1.2.1a:1995, 
Tyres and wheels — Specification for metric series tyres — Commercial 
vehicle tyres, published by the British Standards Institution. 
 ISO 4209-1:2001, 
Truck and bus tyres and rims (metric series) — Part 1: Tyres  
 
ISO 10454, Truck and bus tyres — Verifying tyre c apabilities — Laboratory test methods.   
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
iv                                                                                                © EAC 2004 — All rights reserved  
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEW                                                                                                                  
EAST AFRICAN STANDARD                                          EAS 359:2004 
                                                                                                                                     
 
© EAC 2004 — All rights reserved                                                                                                  1 Pneumatic tyres for light trucks — Specification 
 
1 Scope 
 
This East African Standard specifies tyre dimensions, designation, marking requirements and load ratings. It also gives laboratory test requirements for bead unseating, strength and endurance 
performance for light truck tyres. This East African Standard also specifies sampling methods and 
disposition of non conforming tyres.  
2 Application 
 
This East African Standard applies to all pneumatic light truck tyres with both “tube type and tubeless” 
of radial and bias constructions.  It does not apply to any tyre that has been reconditioned or altered 
so as to render it impossible for use or repaired for use as part of motor vehicle equipment.   
For the purposes of this East African Standard, light truck tyre is considered to be a tyre for 
commercial and light truck vans with carrying capacity of up to 1 — 5 tons, ply rating from 6 — 14, rim 
size form 10” — 17.5” and load index from 81 — 144 (for radial tyres having description suffix “C”). 
 
3 Normative references  
 ISO 4223-1, 
Definitions of some terms used in the tyre industry — Part 1: Pneumatic tyres   
 ISO 10191:1995 – TW – 2B/4, 
Methods of test for verifying tyre capabilities , published by the 
International Organization for Standardization 
 
BS AU 50-1.2.4:1994, Method of test for verifying tyre capabilities , published by the British Standard 
Automobile Series  
 
ETRTO Standard manual:2001, Standards for tyres / rims/ valves for ground vehicles  — The 
European tyre and rim technical organization (E.T.R.T.O.) 
 
ETRTO Engineering design information:2001, The European tyre and rim technical organization 
E.T.R.T.O. Design guides and engineering data  
 
JATMA year book (tyres standards):2001 The Japan automobile tyre manufacturers association, Inc  
 
EAS 357, Pneumatic tyres for trucks and buses  — Specification 
 
EAS 124, Rounding off numerical values  
 
The tyre and rim association inc. year book: 2000 – TRA manual 
 
4 Terminology 
 
For the purposes of this East African Standard, the following definitions shall apply: 
 
4.1  
approved rim contour  
an Approved rim contour is one agreed by ETRTO/ TRA/JATMA members for use with a specific tyre 
size designation 
 
4.2  
bead  
that part of the tyre which is shaped to fit the rim. It has a core made of one or several essentially 
inextensible strands with the plies wrapped around the core 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
2                                                                                                © EAC 2004 — All rights reserv ed 4.3  
bead flange and bead seat  
the parts of the rim which support the tyre 
 
4.4  
bead separation  
breakdown of bond between components in the bead area 
 
4.5  
belt or bracing ply – radial tyre 
a layer of material underneath the tread, laid substantially in the direction of the tread center-line that restricts the carcass in a circumferential direction 
 
4.6  
bias belted tyre   
a pneumatic tyre structure of bias ply (diagonal) type the carcass being restricted by a substantially 
inextensible circumferential belt – construction code “B” 
 
4.7  
bias ply tyre  
a pneumatic tyre  in which the ply   cords that extend form the beads and are laid at alternate angles substantially less than 90°  to the centerline of tread- construction code “B” 
 
4.8  
beaker- diagonal tyre  
an intermediate ply between carcass and tread centerline of the tread 
 
4.9  
carcass  
the rubber- bonded cord structure of a tyre integral with bead, which contains the inflation pressure 
 
4.10  
chunking  
breaking away of pieces of the thread 
 
4.11  
cord 
textile or non – textiles strands (threads) used in various components of the tyre carcass, 
plies, belt, breakers, etc  
 
4.12 
cord separation  
cord parting from adjacent rubber compounds 
 
4.13  
cracking a
ny parting within the tread, sidewall  or innerliner of the tyre extending to cord material  
 4.14  cyclic
 
service condition marked on earthmoving equipment tyres in ‘transport and /or loading’ 
 
4.15  
design tyre dimension  
the figures or values used for tyre design purposes 
 
4.16  
diagonal (bias ply) tyre  
describes a pneumatic tyre structure in which the ply cords extend to the beads and are laid at alternate angles substantially less than 90°   to the centerline of the tread - construction code  “D” or  “-“ DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                3  
4.17  
groove  
the  space between two adjacent tread ribs 
 
4.18 
grown Tyre  
a tyre which has undergone expansion due to use in service   
 
4.19  
gutter  
the groove in the rim base in which the rim parts, such as the spring lock  ring or  detachable spring flange, fit and are retained buy the gutter tip 
 
4.20 
implement   
Tyres designed primarily for agricultural machines or implements (vehicles in category S) or for 
agricultural trailers (vehicles in category R). However they may also equip either front steering wheels and drive wheels of agricultural and forestry tractors (vehicles in category S). They are not suitable for 
sustained high torque service 
 
4.21  
innerliner  
the layers forming the inside surface of a tubeless tyre that contains the inflating medium within the 
tyre 
 
4.22  
innerliner separation 
parting of innerliner from cord material in the carcass 
 
4.23  
inflation pressure  
the pressure taken with the tyre at ambient temperature and does not include any pressure build up 
due to tyre usage  
4.24  
load capacity  
the maximum load a tyre is permitted to carry under specified operating conditions 
 
4.25  load index
 
a numerical code associated with the maximum load a tyre can carry at the speed indicated by  its 
speed symbol under service conditions specified by the tyre manufacturer  
4.26  
ply rating  
an index of casing strength, not necessarily representing number of cord plies in a tyre 
 
4.27  maximum overall (grown) diameter in service dC,) 
the maximum overall diameter plus manufacturing  tolerances and tolerances for service  growth  
 
4.28  
maximum tyre dimensions in  service 
inflated tyre dimensions including permanent growth in service 
 
4.29  
maximum  load rating  
maximum load that the tyre is rated   to carry in single formation at the reference speed 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
4                                                                                                © EAC 2004 — All rights reserv ed 4.30  
maximum permissible inflation pressure 
maximum cold inflation pressure to which a tyre may be inflated.  It does not include build up due to 
tyre usage  
 
4.31  
measuring rim 
the rim specified by the relevant sub – committee for the measurement of the tyre   
 
4.32  
measuring rim width 
linear distance between the rim flanges of the measuring  rim  
4.33  moped (or cyclomoteur or ciclomotore) 
motorcycle tyres designed for motorcycles having a speed capability less than or 50 km/h 
 
4.34  
new tyre 
a tyre which has neither been used nor subjected to retreading operation 
 4.35  
nominal aspect ratio 
one hundred times the ratio of the section height to the section width of the tyre on its theoretical rim 
 4.36  
nominal aspect ratio design 
one hundred times the ratio of the design section height to the nominal section width (h/s). For some 
existing code designated series the value shown is only approximate 
 
4.37  
nominal rim diameter 
the nominal rim diameter is a size code figure for reference purposes only, as indicated in the tyre and 
rim size designation 
 
4.38  
nominal section width  
the section width of an inflated tyre mounted on its theoretical rim and indicated in the tyre size 
designation 
 4.39  
not for highway use (NHS) 
motorcycle tyres designed for off-the-road applications. They must not be used on the public highway 
 4.40  
open splice 
any parting at any junction of tread, sidewall or innerliner that extends to cord material 
 4.41  overall diameter  
the diameter of an inflated tyre at the outermost surface of the tread 
 
4.42  
overall width  
the linear distance between the outsides of the sidewalls of an inflated tyre including elevations due to 
labeling (markings), decorations, and protective bands or ribs  
4.43  
ply 
a layer of rubber - coated parallel cords. DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                5  
4.44  
ply separation  
parting of rubber compound between adjacent plies. 
 
4.45  
play rating  
index of tyre strength often designated as PR  
4.46  
pneumatic tyre   
a mechanical device made out of rubber, chemicals, fabric and steel or other material, which when mounted on an automotive wheel provides traction and contains the gas or fluid that sustains the total 
load 
 
4.47  
radial ply tyre  
a pneumatic tyre in which the ply cords extend to the beads and are laid substantially at 90 degrees to 
the centerline of the tread 
 
4.48   
regroovable  
commercial vehicle tyres designed with sufficient undertread to allow a subsequent re-grooving of the 
original tread pattern  
4.49  
reinforced (or REINF)   
passenger car tyres and/or motorcycle tyres designed for loads and inflation pressures higher than 
the standard version  
 
4.50  
retreaded  tyre  
a tyre to which a new tread has been applied to extend the useful life of the tyre 
 
4.51  
rim  
that part of the wheel on which the tyre or tyres and tube assembly is mounted and supported 
 
4.52  
rim width   
the linear distance between the flanges of the rim  
4.53  road
  
service description marked on radial construction earthmoving equipment tyres in highway service 
 
4.54  
section height  
half the difference between the overall diameter and the nominal rim diameter 
 
4.55  
section width  
the linear distance between the outsides of the sidewalls of an inflated tyre excluding elevations due 
to labeling (markings), decorations, or protective bands or ribs 
 
4.56  service description
 
in addition to the Tyre Size Designation, a tyre may be identified by a Service Description consisting 
of a load index (or two load indices in the case of single/dual fitments) and a speed symbol  DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
6                                                                                                © EAC 2004 — All rights reserv ed 4.57  
sidewall  
the part of the pneumatic tyre between the tread and the bead 
 
4.58  
sidewall rubber  
the rubber layer on the sidewall of the tyre and over the carcass, which may include ornamental or 
protective ribs and fittings lines  
4.59  
sidewall separation  
parting of the rubber compound from the cord material in the sidewall  
4.60  size factor
 
the sum of the section width and the outer diameter of a tyre determined on the test rim 
 
4.61  
special tread tyre (ET)  
tyre whose tread pattern is primarily designed to provide satisfactory performance under special 
service conditions (e.g. mixed, use, on and off-road, city bus, etc.)  
4.62  
specified rim diameter   
the diameter at the intersection of the planes of the rim bead seat and the rim flange depending on the 
rim design, it can be either smaller or larger than the nominal rim diameter 
 
4.63  
speed category   
a code indicating tyre speed capabilities  
 
4.64 
solid  
rubber solid tyres for pneumatic tyre rims  
 
4.65 
temporary use only   
passenger car tyres intended for temporary use as a spare in one position only  
 
4.66  
test rim  
any rim on which the tyre may be fitted that conforms to the dimensions of the recommended rims for 
the particular tyre designation and type 
 
4.67  
test drum speed 
peripheral speed of the test drum  
 4.68
 
tread rib 
a tread section that runs circumferentially around the tyre  
 4.69
  
tread separation 
pulling away of the tread from the tyre carcass  
 
4.70  
theoretical rim  
a rim having a width of specified ratio to the nominal section width  
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                7 4.71  
tread  
the part of a pneumatic tyre which normally comes in contact with the ground / road  
 
4.72  
tubeless  
tyres specifically designed for fitment without an inner tube on appropriate rims  
 
4.73  
tyre measurement  
measurements taken on the unloaded tyre mounted on its measuring rim at the recommended 
inflation pressure and conditioning 
 
4.74  
valve aperture  
the hole or slot in the rim which accommodates the valve for tyre inflation 
 
4.75  
wheel   
a rotating load carrying member between the tyre and the axle, usually consisting of two major parts, 
the rim and the wheel center 
 
4.76  
well  
that part of the rim so located with sufficient depth and width to enable the beads to be mounted and 
dismounted over the mounting side rim flange or bead seat taper 
 
Tyre codes used in tyre industries 
 
4.77   
C 
commercial vehicle tyres for service on light duty vehicles  
 4.78
   
CT  
special design passenger car tyres suitable for fitment on CT rim only  
 
4.79   
DP  t
yres specifically designed for mud and snow (Winter). MS, M&S, M.S and M-S or M+S are also used 
 
4.80  
extra load (or XL)  
passenger car tyres and/or motor- cycle tyres designed for loads and inflation pressures higher than the standard version 
 
4.81   
S  
tyre intended for temporary use as spare (no more than one in use at a time)  
 
4.82   
T 
tyres intended for temporary use as a spare, in one position only at a time, with inflation pressures 
higher than those of Standard or Reinforced tyres 
 
4.83   *
 
symbols used to identify different versions load capacity/ inflation pressure of earthmoving  
equipment tyres in radial construction  DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
8                                                                                                © EAC 2004 — All rights reserv ed 4.84   
FRT  
commercial vehicle tyres restricted to the equipment of non-driven axles, excluding motor vehicle front 
steering axles 
 
4.85   
IMP 
tyres designed primarily for agricu ltural machines or implements  
 
4.86   
M/C  
motorcycle tyres which are designed for use on M/ C motorcycle rims having a bead seat diameter 
which differs from that  of rims with the same designation, designed for passenger car, commercial 
vehicles and agricultural applications 
 
4.87   
M+S  
tyres specifically designed for mud and snow (Winter). MS, M&S, M.S and M-S or DP are also used 
 
4.88   
IND 
agricultural tyres for traction wheels for construction applications, with load capacities and inflation 
pressures which differ from those for tyres with the same size designation for use on agricultural 
tractors  
4.89   
MPT  
commercial vehicle tyres for service on multipurpose trucks  
 
4.90   
MST   
motorcycle tyres designed for special service having a wider tread than equivalent sizes with the same tyre size designation 
 
4.91   
PR 
identifies different versions (load capacity/inflation pressure) of tyres having the same size designation  
 
4.92   
TG (or GRADER)   
existing diagonal construction grader service tyres  
 
5 General requirements 
 
5.1 Materials  
 The basic compound used in the construction, shall be of natural rubber, synthetic rubber or a  
combination thereof. 
 
5.2 Ozone resistance 
 
Each tyre as part of production shall contain sufficient anti-oxidants and anti-ozonants to provide standard commercial resistance to weathering. 
 
5.3 Temperature ability  
 Each tyre shall have an inherent capability of acceptable performance in ambient air temperature 
ranging from  -5 
°C to 50 °C. 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                9 5.4 Workmanship 
 
A Tyre covered under this standard shall show no evidence of poor workmanship or any imperfections 
which may impair serviceability.  
 
5.5 Age of rubber 
 Tyres covered under this standard shall not be more than 5 years from the date of manufacture.  
5.6 Dimensions labeling 
 Nominal section width of the tyres shall be indicated in millimeters, ending with 0 or 5 such that in any 
one series of tyres with same nominal aspect ratio, the values shall end with 0 or with 5. An equivalent   
marking in inches is permitted. The rim diameter shall always be indicated in inches to the nearest 
0.5". 
 
6 Designation and marking  
 
Each tyre shall have permanently moulded into or onto each sidewalls in letters and numbers not less 
than 2 mm deep or protruding out with the information shown below: 
 
6.1 Size designation 
 
6.1.1  Each tyre shall have one size designation in metric except that equivalent inch size 
designation may be used. The characteristics shall be indicated as follows: 
 
Nominal                            Nominal            Tyre                           Nominal                                       
section       and/or            aspect              construction               rim 
width                                ratio                  code                     diameter 
 
 
NOTE All low profile tyres (Aspect Ratio of 70 and below) shall have nominal aspect ratio.  
 
6.1.2 Nominal section width of the tyre shall be indica ted in millimeters, ending either in 0 or 5, so 
that in any one series of the tyres with the same nominal aspect ratio, the values shall all end with 0 or end with 5. An equivalent marking in inch is permitted.  DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
10                                                                                                © EAC 2004 — All rights reser ved  
For sizes mounted on 5° tapered (code- designated) rims, the nominal section width shall end with 5. 
 
6.1.3 Nominal aspect ratio (H/S) - 100 times the ratio of the section height to the section width of 
the tyre on its theoretical rim, shall be expressed as a percentage and in multiple of  5. 
 
NOTE Theoretical rim is a rim having a width of specified ratio to the nominal section width. 
 
6.2 Tyre structure/construction code 
 
The tyre construction code shall be as follows   B for bias – belted construction  
 
D/- for diagonal construction   
R for radial ply construction  
 6.3 Service description  
 
6.3.1 
The word TUBELESS shall appear on the tyre to characterize tyres that can be used without 
a tube.  
Where no TUBELESS appears on the tyre sidewalls, tyres shall be intended for fitment with and appropriate inner tube.
 
 
6.3.2 Load index  
 
The maximum tyre load capacity corresponding to the service conditions specified by the tyre 
manufacturer, shall be indicated by a load index from Table 6. This indication is understood to be per tyre for a single mounting. 
 
6.4 Marking   
 
Each tyre shall be labeled with a recognized  quality / safety mark to show that the tyre conforms to 
respective national, regional or international standar d e.g DOT, EC, KBS, TBS etc.  The tyre may also 
be marked with any other identification assigned to the manufacturer. 
 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                11 
 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
12                                                                                                © EAC 2004 — All rights reser ved 7 Calculation of tyre dimensions  
 
7.1 Calculation of design tyre dimensions  
 
7.1.1 Theoretical rim width (R th) 
 
Rth = K1SN                                                                                                                     Formula (1)  
 
K1  Theoretical rim width;  
 
SN  Nominal section width;  
 
Rth.  Ratio; 
 
K1 = 0.7 for tyres having nominal aspect ratio (H/S) from 50 to 95 inclusive;  
 K
1 = 0.85 for tyres having nominal aspect ratio (H/S) from 30 to 45 inclusive. 
 No rounding is to be performed after calculation of theoretical rim width. 
 
7.1.2  Measurement of rim width (Rm)  
 
Rm Standardized rim width closest to the theoretical or to the calculated measuring rim width if it 
differs from the theoretical. 
 7.1.3 Design section width (S)  
 
S
 = SN + K2(Rm - Rth.)                                                                                               Formula (2) 
 
S Design section width;                                                    
 
SN Nominal section width; 
 
Rm  Measuring rim width;  
 
Rth  Theoretical rim width.  
 
K2 = 0.4 
 
7.1.4  Minimum section width (S min) 
 
Wmin = SC                                                                                                                        Formula (3) 
 
S - Design section width; 
 
C - Coefficient for the tyre category.  
7.1.5   Design section height (H)  
       H/S        H = S
N    .                                                                            Formula (4) 
         100 
 
H - Design section height;  
             
  S N - Nominal section width; 
              
H/S - Nominal aspect ratio (example: 60 series = 60). 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                13  
7.1.6  Design tyre overall diameter (D 0) 
 
                                                                                                                          Formu la (5) 
    
Do - Design overall diameter; 
 
H - Design section height; 
 
Dr - Norminal rim diameter (see Note 3 below). 
 
 
7.1.7  Maximum and minimum new tyre diameter (domax, domin)  
 
Domax = Dr = 2Hb                                      Formula (6)  
  
Domin = Dr = 2Hd                                                                                                            For mula (7)
  
Domax -  Maximum new tyre outer diameter.                                     
 
Domin  - Minimum new tyre outer diameter. 
 H - Design section height. 
 
(
Domax DO min ) - Coefficient ( ±) to provide for design and manufacturing differences 
see Table 7. 
 
Dr - Nominal rim diameter. 
 
Rounding to the nearest millimeter, according to EAS 124(see clause 3), is to be performed. 
 
7.2  Calculation of tvre dimensions in service  
 
7.2.1   Maximum overall width in service (W max)  
 
Wmax = Sa                                        Formula (8)  
              W
max - Maximum overall width in service. 
 
S -  Design section width. 
 
a - Coefficient to provide for design and manufacturing differences and for the increase of the   Design 
Section Width due to protective ribs, lettering, embellishments and growth due to service 
 
See relevant sub-section for the tyre category concerned.  
Round to the nearest millimiters, in accordance with EAS 124(see clause 3). 
 
7.2.2   Maximum overall diameter in service (D O ,max).  
 
Do, max= Dr+2Hb                           Formula (9) 
 
Do - Maximum overall diameter in service; 
 
H - Design section height; 
 
Dr - Nominal rim diameter. 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
14                                                                                                © EAC 2004 — All rights reser ved Rounding to the nearest millimeter, in accordanc e with EAS 124,is to be performed after final 
calculation. 
 
7.2.3  Maximum section height in service(H)  
 
 
 
 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                15  
8 Test requirements 
 
8.1 Test sample 
 
Two tyres with identical characteristics, e.g. size designation and service description or maximum load 
rating, ply rating and speed capability, shall comprise a test sample.  
8.1.1  One tyre shall be used for the measurement of physical dimensions, resistance to bead 
unseating and strength in sequence.  
8.1.2  A second tyre for the endurance test. 
 The pressures, loads, speeds and durations shall be as specified for each test method. Each test sample shall conform to the requirements specified in 6.2 to 6.5 as appropriate. 
 
8.2 Test equipment 
 
The test equipment consists of 
 
8.2.1  Test drum , cylindrical driven flywheel (drum having a diameter of 1.7 m ± 2 % or 2 m ± 2 %). 
 The surface of the drum shall be smooth steel and the width of the test surface shall be equal to or 
exceed the overall width of the test tyre. For the test drum, the loading device shall have a capacity of at least 5700 kg and the accuracy shall be within ± 1 % of the full scale. For the test drum, the speed 
capability of the equipment shall be adequate for t he requirements of the test methods. The accuracy 
of the test drum speed shall be within + 2 km/h to - 0 km/h. 
 
8.2.2  Plunger , cylindrical steel plunger of sufficient length with a hemispherical end and of diameter 
as shown below:  
Table 2 — Recommended pressures for measurement of tyre dimensions 
 
Type Pressure kPa 
Standard load ap-type light load version 180 
Extra load/reinforced version 220 
T-type Temporary-use spare type 420 
 For the plunger equipment, the loading device shall permit gradual application of the force. Indicators of displacement and force provided shall have an accuracy within ± 1 % of full scale. For the plunger 
equipment, the displacement speed shall be controlled with an accuracy within ± 3 % of the full scale. 
 
8.2.3 Bead unseating block 
 The bead unseating block loading device shall permit progressive application of the force. Indicators of displacement and force provided shall have an accuracy ± 1 % of full scale. The displacement speed of the bead unseating block shall be controlled with an accuracy within ± 3 % of the full scale. 
 
8.2.4  Inflation pressure gauges , with a maximum scale value of at least 500 kPa with an accuracy 
within ±1:5 k Pa. 
 8.3 Testing 
 
8.3.1 Non destructive testing 
 
8.3.1.1  Physical dimensions measurement 
 
The tyre physical dimensions shall be determined under uniform ambient conditions as follows:  DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
16                                                                                                © EAC 2004 — All rights reser ved 8.3.1.1.1 Tyre preparation 
 
The sample shall be mounted on a recommended test rim for that tyre size designation and inflated to 
the applicable pressures in single formation as shown in Tyre Dimension Table 2. Then the tyre shall 
be conditioned at ambient room temperature for a minimum of 24 h for bias construction and 3 h for radial construction. The pressure is then re-adjusted to the original value. 
 
8.3.1.1.2  Test procedure  
 a) The section width and overall width are callipered at six points approximately equally spaced 
around the tyre circumference. The average of the measurements of the section width and 
overall width respectively is recorded. 
 
b) The tyre overall diameter is determined by measuring the maximum circumference of the tyre 
and dividing this dimension by = 3.1416. 
 The actual section width and overall width for each tyre measured in accordance with this procedure 
shall not be less or exceed the section width specified in the submission made by the manufacturer or in any standard tyre and rim matching information for its size designation and type, by more than 7 %. 
 
8.3.1.2 Tubeless bead unseating test  
 
This test applies to tubeless tyres only. 
 
8.3.1.2.1 Preparation of tyre  
 
Wash the tyre, dry it at the beads, and mount it without lubrication or adhesive on a clean, painted test rim. Mount the tyre on a test rim and inflate it to the pressure specified in Tyre Dimension Table 4. 
 
8.3.1.2.2 Test procedure  
 
Mount the tyre and rim assembly on a fixture. 
 
Position the bead unseating block (8.2.3) against the tyre sidewall at a horizontal distance P as shown 
in Table 3. 
 
Apply a force through the block to the tyre outer sidewall at a rate of 50 mm/min ± 2.5 mm/min. 
 
Table 3 — Distance P from bead unseating block 
 
Dimension  P  Nominal Rim Diameter 
code T type temporary use spare tyre All other tyres 
10 
12 
13 14 
15 
16 17 
18 
19   
 
226 
239 251 
269 
290 305 216 241 
254 
267 279 
292 
305 318 
330 
 
290 315 340 
365 
390 
415  229 
241 
254 
267 279 
292 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                17  
Increase the force until the bead block unseats or until the prescribed value is reached Tables 4 and 
5. Repeat the test at least four times at places approximately equally spaced around the tyre 
circumference. 
 
8.3.1.2.3 Qualification criteria  
 When tested in accordance with 8.3.1.2.2, the applied force required to unseat the tyre bead at the point of contact shall not be less, in relation to the nominal section width of the tyre, than that shown in 
Table 2. 
 
Table 4 — Bead unseating force 
 
Nominal section,  S, width mm Force N 
S < 160 6670 
160≤S <205 8890 
S ≥ 205 11120 
 
For light truck and high pressure "temporary use spare" tyres, identified by a prefix T in the size 
designation, the force required to unseat the tyre bead shall not be less, in relation to the tyre load 
index, than that given in Table 4. 
 
Table 5 — Bead unseating force for temporary use spare tyres 
 
Load index Force N 
≤75 6670 
76 to 92 8890 
≥93 11120 
 
8.3.2 Destructive testing   
 8.3.2.1 Strength test/ destructive test
 
 
8.3.2.1.1  Preparation of tyre  
 
Mount the tyre on a test rim and inflate it to the pressure specified for maximum load rating in single 
formation or maximum dual load. 
 Maintain the assembly at test room temperature for at least 3 h for radial construction and 24 h for 
bias/diagonal construction. 
 
8.3.2.1.2  Test procedure  
 
a) Readjust the tyre pressure to that specified in 8.3.2.1.1(a) and mount the assembly on a fixture. 
 b) Position the plunger as near to the centerline as possible, avoiding penetration into the tread 
grooves and force the plunger perpendicularly into the tread at a rate of 50 mm/min ± 2.5 mm/min. 
 
c) Record the force and penetration at the moment of breaking (see also 8.3.2.1.2 (g) ) at each of 
five test points approximately equally spaced around the tyre circumference. Check the pressure 
before moving to the next test point. 
 d) If the tyre fails to break before, the plunger is stopped on reaching the rim well, then the tyre is 
deemed to have passed the test at that point. 
 e) Compute the breaking energy, W, in joules for each test point, except those considered by 
8.3.2.1.2(d) by means of the following formula: 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
18                                                                                                © EAC 2004 — All rights reser ved 2000P FW×=  
 
where 
 
F is the force, in Newtons; 
P is the penetration, in millimeters. 
 
f) Determine the breaking energy value for the tyre by computing the average of the values 
obtained. 
 
g)  When an appropriate device which automatically evaluates the value of the energy W is 
available, the penetration can be stopped shortly after having achieved the prescribed value specified in Table 6. 
 
h) In the case of tubeless tyres, means may be provided to ensure the retention of the inflation 
pressure for the duration of the test. 
 
8.3.2.1.3 Qualification criteria 
 a) Each test sample shall meet at least the requirements for minimum breaking energy specified in 
Table 6, when tested in accordance with 8.3.2.1.2. 
 
Table 6 — Minimum breaking energy 
 
Minimum breaking energy, J 
Other 
tyres Load rang
e PR 
Rim diameter 
code ≤12 Rim diameter code 13 and 14 
tube type marked ‘LT’ Other tyres marked 
"L T" Tubeless with 
rim diameter code 13 to 17.5 inclusive Tube 
type Tubeless 
A 
B 
C 
D E 
F 
 2 
4 
6 
8 10 
12 68 
136 
203 
271 339 
407 - 
192 
271 
384 - 
- 226 
294 
362 
514 576 
644 - 
- 
768 
893 1412 
1785 - 
- 
576 
734 
972 1412 
 
G 14   712 2282 1695 
 
b) For high pressure” temporary use spare”  tyres,  identified by a prefix T  in the size   designation, 
the energy required shall be  
 
i) 295 J for tyres  with a maximum load rating of 400 kg and above; 
 
ii) 220 J for tyres with a maximum load rating below 400 kg. 
 
8.3.2.2 Endurance test  
 
8.3.2.2.1  Preparation of tyre   
 
a) Mount the tyre on a test rim and inflate it to the pressure specified in tyre dimension tables.  
 b) Maintain the tyre and rim  assembly at an ambient temperature of not less than 35 °C and not 
more than 41 °C for at least 3 h. 
 
8.3.2.2.2 Test procedure 
 
a) Re-adjust the tyre pressure to the value specified in 8.3.2.1.1 (a) immediately before testing. 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                19 b) Mount the tyre and rim assembly on a test axle so that the tyre may be pressed radially against 
the outer face of test drum. 
 
c) During that test, the ambient temperature at a distance of not less than 150 mm and not more 
than 1 m from the tyre, shall be at least 35 °C and not more than 41 °C. No provision shall be 
made for cooling the tyre during the test. 
 d) Conduct each successive phase of the test without interruptions at the speed with loads and test 
periods as shown in; 
 
i) Table 7, for tyres with Load Index (single) up to 121 inclusive and speed symbol up to 
P. 
 
ii) 8.3.2.2.3, for tyres with Load Index single up to speed symbols Q and above; 
 iii) Table 7, for tyres with Load Index (single) 122 and above. 
 
Table 7 — Endurance test parameters 
 
 
 
e) Throughout the test, the inflation pressure shall not be corrected and the test loads shall be kept 
constant at the value corresponding to each test period. 
 
8.3.2.2.3  Specific conditions for tyres with speed symbol Q and above. 
 
a) The load applied shall be 
 
i) 90% of maximum load rating on 1.7 m test drum diameter. 
 
ii) 92% of maximum load rating on 2.0 m test drum diameter. 
 
b) The initial test speed shall be equal to tyre's speed category minus 20 km/h. 
 
c) Operate the test equipment to bring the test drum speed up to the initial test speed for a period of 
10 min. DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
20                                                                                                © EAC 2004 — All rights reser ved  
d) Operate the equipment with the test drum speed at the initial test speed for 10 min then at the 
initial test speed plus 10 km/h for at least 10 min. 
 
e) Finally operate the equipment for 30 min at the tyre's rated speed category.  
Total duration for testing is 1 hr. 
 
8.3.2.2.4  Qualification criteria  
 
When the tyre has been subjected to the laboratory endurance test specified in 8.3.2.2, using a test rim and a valve which undergo no permanent deformation and allow no loss of air, there shall be no 
visual evidence of tread, sidewall, ply, cord, innerliner, belt or bead separation, chunking, open 
splices, cracking or broken cords. 
 The tyre pressure measured immediately after the test shall not be less than the initial pressure 
specified in 8.3.2.1.1a). 
 
9 Test tyre sampling 
 
9.1 Every shipment of the same size, brand, shall be accompanied with manufacturer test data. 
 
9.2  Random sampling of subsequent shipment of the same size, brand, manufacturer shall be 
done to confirm compliance of manufacturer's test data. A minimum of three (3) test sample tyres per 
size, brand name, manufacturer, shall be taken for destructive tests. 
 
9.3 Sampling shall be done at the port of entry and /or distribution point. 
 
10 Non-conforming tyres 
 
10.1 No tyre that is designed and manufactured for use on light trucks/commercial automobiles, 
that does not conform to the requirements of this standard shall be sold, offered for sale, introduced or 
delivered for introduction into, or imported into East Africa. 
 
10.2 The National Standards Body shall conduct random market surveillance inspection to ensure 
non existence of illegally introduced/delivered tyres in the region and shall conform to clause 6 of this standard.  
10.3 The National Standards Body shall take the resp onsibility of ensuring public awareness of the 
ban of non- conforming tyres.  
11 Disposition of nonconforming tyres 
 
11.1 To ensure that the consumer is protected from exposure to nonconforming tyres, the importer 
and/or manufacturers shall take the responsibility of  shipping back to sour ce of origin all non 
conforming consignments 
 
11.2 If the nonconforming tyres are in the market, it shall be the responsibility of the local National 
Standard Body to ensure that consumers are protected from their use. 
 
11.3 Testing 
 
The responsibility for testing shall be on the National Standards Body or their assigned agencies.  
12 Certification 
 
Certification shall be done in accordance with the procedures of the National Standards Body. The 
procedures for certification shall be obtained from the National Standards Body. It shall be the 
responsibility of the local National Standard Body to ensure that the importers or manufacturers with a DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                21 “Certificate of Conformance” for the size, brand and manufacturer for a consignment meet the 
requirements of this standard. 
 
At every tyre selling point, there shall be a certified true copy of certificate of conformance.  
 
12.1 Test certificate validity 
 Certificate of conformance shall be valid for a period recommended after which the importer and/or manufacturer shall have to reapply for re-certification. 
 
This certificate of conformance shall always remain a property of the issuing bureau and shall be returned to issuing bureau before a new one is issued. 
 
12.2 Sample tyres for test  
 The local National Standards Body shall select for sample testing from the tyre sizes:    
 
One size if an application has maximum of 5 sizes.   
Two  sizes if an application has between 6 and 10  sizes.   
 Three sizes if an application has 11 and more sizes.  
 
These tyres shall be sent to the National Standards Body.  DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
22                                                                                                © EAC 2004 — All rights reser ved Table 8 — Load Index 
 
Load  TLCC  Load  TLCC  Load  TLCC Load  TLCC  Load  TLCC  Load  TLCC  Load  TLCC  
Index   Index   Index   Index   Index   Index   Index   
(LI)  kg  (LI)  kg  (LI)  kg  (LI)  kg  (LI)  kg  (LI)  kg  (LI)  kg  
0  46  40  140  80  450  120  1 400  160  4 500  200  14 000  240  45 000  
1  46,2  41  145  81  462  121  1 450  161  4 625  201  14 500  241  46 250  
2  47,5  42  150  82  475  122  1 500  162  4 750  202  15 000  242  47 750  
3  48,7  43  155  83  487  123  1 550  163  4 875  203  15 500  243  48 750  
4  50  44  160  84  500  124  1 600  164  5 000  204  16 000  244  50 000  
5  51,5  45  165  85  515  125  1 650  165  5 150  205  16 500  245  51 500  
6  53  46  170  86  530  126  1 700  166  5 300  206  17 000  246  53 000  
7  54,5  47  175  87  545  127  1 750  167  5 450  207  17 500  247  54 500  
8  56  48  180  88  560  128  1 800  168  5 600  208  18 000  248  56 000  
9  58  49  185  89  580  129  1 850  169  5 800  209  18 500  249  58 000  
10  60  50  190  90  600  130  1 900  170  6 000  210  19 000  250  60 000  
11  61,5  51  195  91  615  131  1 950  171  6 150  211  19 500  251  61 500  
12  63  52  200  92  630  132  2 000  172  6 300  212  20 000  252  63 000  
13  65  53  206  93  650  133  2 060  173  6 500  213  20 600  253  65 000  
14  67  54  212  94  670  134  2 120  174  6 700  214  21 200  254  67 000  
15  69  55  218  95  690  135  2 180  175  6 900  215  21 800  255  69 000  
16  71  56  224  96  710  136  2 240  176  7 100  216  22 400  256  71 000  
17  73  57  230  97  730  137  2 300  177  7 300  217  23 000  257  73 000  
18  75  58  236  98  750  138  2 360  178  7 500  218  23 600  258  75 000  
19  77,5  59  243  99  775  139  2 430  179  7 750  219  24 300  259  77 500  
20  80  60  250  100  800  140  2 500  180  8 000  220  25 000  260  80 000  
21  82,5  61  257  101  825  141  2 575  181  8 250  221  25 750  261  82 500  
22  85  62  265  102  850  142  2 650  182  8 500  222  26 500  262  85 000  
23  87,5  63  272  103  875  143  2 725  183  8 750  223  27 250  263  87 500  
24  90  64  280  104  900  144  2 800  184  9 000  224  28 000  264  90 000  
25  92,5  65  290  105  925  145  2 900  185  9 250  225  29 000  265  92 500  
26  95  66  300  106  950  146  3 000  186  9 500  226  30 000  266  95 000  
27  97,5  67  307  107  975  147  3 075  187  9 750  227  30 750  267  97 500  
28  100  68  315  108  1 000 148  3 150  188  10 000  228  31 500  268  100 000  
29  103  69  325  109  1 030 149  3 250  189  10 300  229  32 500  269  103 000  
30  106  70  335  110  1 060 150  3 350  190  10 600  230  33 500  270  106 000  
31  109  71  345  111  1 090 151  3 450  191  10 900  231  34 500  271  109 000  
32  112  72  355  112  1 120 152  3 550  192  11 200  232  35 500  272  112 000  
33  115  73  365  113  1 150 153  3 650  193  11 500  233  36 500  273  115 000  
34  118  74  375  114  1 180 154  3 750  194  11 800  234  37 500  274  118 000  
35  121  75  387  115  1 215 155  3 875  195  12 150  235  38 750  275  121 000  
36  125  76  400  116  1 250 156  4 000  196  12 500  236  40 000  276  125 000  
37  128  77  412  117  1 285 157  4 125  197  12 850  237  41 250  277  128 500  
38  132  78  425  118  1 320 158  4 250  198  13 200  238  42 500  278  132 000  
39  136  79  437  119  1 360 159  4 375  199  13 600  239  43 750  279  136 000  
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                23  
Table 9 — Pressure unit conversion table 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
24                                                                                                © EAC 2004 — All rights reser ved 
 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                25 
 
 
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26                                                                                                © EAC 2004 — All rights reser ved 
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                27 
 
 
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28                                                                                                © EAC 2004 — All rights reser ved  
 
 
   
 
  
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 359:2004  
© EAC 2004 — All rights reserved                                                                                                29  
 
 DRAFT UGANDA STANDARD ON PUBLIC REVIEWEAS 358:2004  
30                                                                                                © EAC 2004 — All rights reser ved 
 
 
 
 
  
  DRAFT UGANDA STANDARD ON PUBLIC REVIEW                                                                                                      EAS 359:2004  
 
 
© EAC 2004 — All rights reserved