Bsi bs au 050 1 0 1 1999 (iso 13326 1998)

BRITISH STANDARD AUTOMOBILE SERIES BS AU 50 1 0 1 1999 ISO 13326 1998 Tyres and wheels — Part 1 Tyres — Section 0 General — Subsection 1 Method of test for measuring tyre uniformity ICS 43 040 50; 83[.]

ICS 4 0 0.5 ; 8 1 0.0

This Bri shStan ard, ha ing

b en pre ared u der the

directonof the Eng ine ring

SectorCommi e , was

publishedu der the authoriy

ofthe Stan ards Commi e

an comes into efect on

1 Ma 1 9

© BSI0 -2 0

ISBN 0 5 0 3 6 4 0

This BritishStand rd reproduces v erb tim ISO13 26:19 8 and implements it

as the UK national stand ard

The UK p rticip tion in its prep ration was entrusted to Tech ical Commit e

AUE/4, Ty res and whe ls for motor v ehicles, which has the responsibi ty to:

— aid enq uirer to u d er tand the text;

— present to the responsible international/ European commit e any

enquiries on the interpretation, or proposals for chang e, and ke p the UK

interests informed;

— monitor related international an European dev elopments and

promulg ate them in the UK

A lst of org anizations represented on this commit e can be obtained on

req uest to its sec etary

Cros - referenc s

The BritishStand ard s which implement international or European

publcations refer ed to in this document ma be fou d in the BSI Stand ards

Catalog ue u der the section entitled “ International Stand ards Cor espondence

Index”, or b using the “Find” faci ity of the BSI Stand rd s Electronic

Catalog ue

A British Stand rd do s not purport to include al the neces ary prov isions of

a contract User of British Stand ard s are responsible for their cor ect

a pl cation

Compl anc with a British Standard does not of itselfconfer imm unity

f om leg al o l g ations

Sum m ary of pag es

This d ocument comprises a f ont cov er, an insid e font cov er, p g esi andi ,

theISO title p g e, p g esi to iv , p g es1 to10 and a b ck cover

This stand rd has be n upd ated ( se copy rig ht d ate) and ma hav e had

amend ments incorporated This wi l be indicated in the amendment ta le on

the inside f ont cov er

Am endm ents is ued sinc publ cation

© BSI 0 -2 0

i

Pag e

© BSI 0 -2 0

Pag e

Fig ure 2 — Ex mples of wav e sha es of for es g enerated b ty re 7

Desc iptors: Ro d v hicles, tyres,pneumatc tyres, tests, determinaton, characteristc

© BSI 0 -2 0

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Foreword

ISO ( the International Org anization for Stand rdization) is a worldwide

federation of national stand ards bodies ( ISO member bodies) The work of

prep ring International Stand ards is normaly car ied out throug h ISO tech ical

commit e s Each member bod interested in a subject for which a tech ical

commit e has be n esta lshed has the rig ht to be represented on that

commit e International org anizations, g ov ernmental and non-g ov ernmental,

in l aison with ISO,also take p rt in the work ISO col a orates closely with the

International Electrotechnical Commis ion ( IEC) on al mat er of

electrotech ical stand ardization

Draft International Stand rds a opted b the tech ical commit e s are

cir ulated to the member bod ies for v oting Publcation as an International

Stand ard requires a prov al b at least7 % of the member bod ies casting a v ote

International Stand ard ISO13 26 was prep red b Tech ical Commit e

ISO/TC31, Tyr es, r ims a nd va lve

Annex A of this International Stand ard is for information only

© BSI 0 -2 0

1

1 Scope

This International Stand rd specifies test methods

car ied out und er control ed conditions for v erify ing

the u iformity of ty res for p s eng er car ,

commer ial v ehicles and motor y cles

NOT Lack of u iformiy arou d a tyre prod ces v riatons in

for es a plied b the tyre to the v hicle an this influence is

re e ted wih e ch re oluton of the ty re At the present state of

the art, howe er, i is imp s ible to man facture p rectly

u iform tyres A rig id control of the complete man facturing

proces can only minimise the u a oida le imp rectons of

materials, comp nents an proces es afectng u iformiy

Methods for measuring the g eometrical run-out of

the ty re in both ra ial an lateral directions are

cov ered , as wel as method s for measuring the

fol owing p rameter :

— rad ial for e v ariation;

— lateral for e v ariation;

— ply ste r;

— conicity

Not al of these measurements wi l neces ari y be

relev ant in ev ery situation

This International Stand rd do s not includ e

method s for measuring the static an the dy namic

u b lance nor method s related to ty re-whe l

as embl es

The test method s specified in this International

Stand ard are not intended for the g ra ation of ty res

or the definition of q ual ty lev els

The fol owing stand ard s contain prov isions which,

throug h reference in this text, constitute prov isions

of this International Stand ard At the time of

publcation, the editions ind icated were v ald All

stand ards are subject to rev isions and p rties to

ag re ments b sed on this International Stand rd

are encourag ed to inv estig ate the pos ibi ty of

a ply ing the most recent edition of the stand rds

indicated below Member of IEC and ISO maintain

reg ister of cur ently v ald International Stand ards

ISO4 0 -1:19 5, Pa ss nger ca r tyr es a nd r ims —

Pa r t1: Tyr es (metr ic s r ie )

ISO4 0 -2:19 4, Pa ss nger ca r tyr es a nd r ims —

Pa r t2: R ims

ISO420 -1:19 3, Tr uck a nd bus tyr es a nd r ims

(metr ic s r ie ) — Pa r t1: Tyres

ISO420 -2:19 3, Tr uck a nd bus tyr es a nd r ims

(metr ic s r ie ) — Pa r t2: R ims

ISO42 3-1:19 9, Definiions o some ter ms us d in

the tyr e ind ustr y — Pa r t1: Pneuma tic tyr es

ISO424 -1:19 5, Motor cycle tyr es a nd r ims

(Cod ed esigna ted s r ie ) — Pa r t1: Tyr es

ISO424 -2:19 0, Motor cycle tyr es a nd r ims

(Cod e-d esigna ted s r ie ) — Pa r t2: Tyr e loa d

r a tings

ISO424 -3:19 7, Motor cycle tyr es a nd r ims

(cod e-d esigna ted s r ie ) — Pa r t3: R ims

ISO5 51-1:19 4, Motor cycle tyr es a nd r ims (metr ic

s r ie ) — Pa r t1: D esign guid es

ISO5 51-2:19 4, Motor cycle tyr es a nd r ims (metr ic

s r ie ) — Pa r t2: Tyr e d imensions a nd loa d -ca r r ying

ca pa ciie

ISO6 5 -1:19 4, Motor cycle tyr es a nd r ims

(cod e-d esigna ted s r ie ) — Dia meter cod es4 to12 —

Pa r t1: Tyr es

ISO6 5 -2:19 0, Motor cycle tyr es a nd r ims

(Cod e-d esigna ted s r ie ) — Dia meter cod es4 to12 —

Pa r t2: R ims

ISO8 5 :19 1, R oa d vehicle — Vehicle d yna mic

a nd r oa d -hold ing a bii y — Voca bula r y

IEC6 6 4-1:19 3,Ind ustr ia l-pr oc s mea sur ement

a nd contr ol equipment — Oper a ting cond itons —

Pa r t1: Clma tic cond itons

VIM:19 3, Inter na tiona l v ca bula r y o ba sic a nd

gener a l ter ms in metr ology, B IPM, IEC, IFCC,ISO,

IUPA C, IUPA P, OIML

3 Definitions

For the purposes of this International Stand rd , the

d efinitions g iv en in ISO42 3-1,ISO8 5 , VIM and

the fol owing a ply

NOT 1 Se Fig ure 1 for the a is reference system

NOT 2 Also refer ISO4 0 -1, ISO4 0 -2, ISO4 0 -1,

ISO4 0 -2,ISO4 4 -1, ISO4 4 -2, ISO4 4 -3, ISO5 5 -1,

ISO5 5 -2,ISO6 5 -1 an ISO6 5 -2

3.1

uniform ity

state in which any characteristic of the ty re is

constant in phase and mag nitude in both static and

d y namic cond itions arou d the cir umference

NOT Uniformiy is concerned wih a is symmetry of mas

d istributon, g eometry an fores g enerated when the solid is in

moton

Lack of u iformiy in a tyre,when i is rotatng arou d is a is,

causes v riatons of fores, which ma v ry wih the ang ular

sp ed an are a plied to the said a is

3.2

peak to peak (total

d iference betwe n the ma imum and the minimum

v alues of measurement sig nal, within a specified

b nd wid th, during one rev olution

3.3

fir t harm onic

peak to peak ampltud e of the fu d mental

f equency component of the Fourier trans orm

representing the v ariation

NOT Is fe uency is e ual to the fe uency of rotaton

© BSI 0 -2 0

3.4

se ond (and hig her order) harm onic

peak to peak ampl tud e of the secon ( or hig her

order) feq uency component of the Fourier

trans orm representing the v ariation

3.5 Forc s

3.5.1

ra ial forc v riation

%F

R

v alue of the v ariation of the for e in the ra ial

direction ( Z a is) of a loa ed ty re which repeats

itself for each rev olution at a fixed load ed rad ius and

a constant spe d, in newtons

3.5.2

lateral forc variation

%F

L

v alue of the v ariation of the for e in the lateral

direction ( Y a is) of a loa ed ty re which repeats

itself for each rev olution at a fixed load ed rad ius and

a constant spe d, in newtons

3.5.3

lateral forc ofset

lateral forc deviation

av erag e v alue of the lateral for e of a loa ed straig ht

f e -rol ing ty re, in newtons

3.5.4

ply ste r

component of the lateral for e ofset which chang es

sig n with a chang e in the direction of rotation, in

newtons

3.5.5

conicity

component of the lateral for e ofset which d oes not

chang e sig n with a chang e in the d irection of

rotation, in newtons

3.5.6

tang ential forc v riation

tractive forc v riation

%F

T

v alue of the v ariation of the for e in fore an aft

d irection ( X a is) of a load ed ty re which repeats

itself for each rev olution at a fixed load ed ra ius an

a constant spe d, in newtons

N T Me surement of this p rameter is not co ered b this

Internatonal Stan ard

Fig ure 1 — Referenc a is system for forc s

F

L

© BSI 0 -2 0

3

3.6 Geom etry

3.6.1

tyre ra ial run- out

v ariation of the ty re rad ius measured

perpendicularly to the spin a is on a cir umference

along the tread surace, excluding the influence of

the v arious g ro v es and v ents located on the trea ,

in mi lmetres

3.6.2

tyre lateral run- out

v ariation of the distance fom a fixed reference

plane, normal to the spin a is, of a g iv en ty re

sid ewal at a g iv en distance f om said a is,

exclud ing the influence of the let ering and other

marking s on the sid ewal , in mi imetres

3.6.3

test rim ra ial run-out

v ariation of the whe l rad ius measured

perpendicularly to the spin a is on a cir umference

along the bea seat, in mi imetres

NOT I is me sured se arately for e ch b ad se t

3.6.4

test rim lateral run- out

v ariation of the d istance fom a fixed reference

plane, perpendicular to the spin a is, of the inside

v ertical portion of the rim flang e at a g iv en distance

f om said a is, in mi lmetres

NOT I is me sured se arately for e ch rim flang e

3.7 Mas distribution

3.7.1

unb lanc

static unbalanc ( 3.7.2) o dynam ic

unb lanc (3.7.3) or both

3.7.2

static unbalanc

prod uct (m×e) of the mas m of the ty re times the

ec entricity e of its centre of g rav ity , ex res ed in

g ram mi imetres

NOT 1 W hen the tyre is spu at an ang ular v lociy Ê,the

statc u b lance g enerates a centrifug al fore F

z normal to the

rotatonal a is, g iv n b :

F

z

=m×e×Ê

2

NOT 2 A pneumatc tyre is actualy deforma le solid,which

me ns that the distributon of mas ,an therefore the

ec entriciy of the centre of g ra iy , ma v ry wih the rotatonal

sp ed.Therefore in practce i should b as umed that e is a

fu cton of Ê

3.7.3

dynamic unb lanc

the product ( I

a –I

d )×µ of the a ial inertia I

a min s

the diametrical inertia I

d times the misal g nment µ

betwe n the ty re main inertia a is and the ty re

rotation a is, measured on a ty re run ing f e ly ,

ex res ed in g ram sq uare mi lmetres

NOT 1 W hen the tyre is spu at a constant ang ular v lociy Ê,

the dynamic u b lance g enerates a b n ing moment M,

p rp n icular to the rotaton a is g iv n b :

M=(I

a –I

d )×sin µ×Ê

2

where sin µ is a pro imated b µ

NOT 2 A pneumatc tyre is actualy a deforma le solid,which

me ns that I

a

an I

d , an therefore the relatv p si ons of their

a es in sp ce, ma v ary wih the rotatonal sp ed.In practcal

terms i should b as umed that I

a

an I

d are fu ctons of Ê

3.8

phase

ang ular orientation of the ty re related to a reference

point

3.9

dire tion of rotation

d irection of rotation as per eiv ed f om the operating

position

se Fig ure 1

NOT Posi v rotaton of the drum is as umed to b a rotaton

arou d the Y a is, when the Z a is mo es clockwise onto the X

a is

3.10

test drum

rotating cy lindrical fly whe l

4 Test equipment a nd its r quir ments

4.1 Apparatus for m easurement of forc s and

g eometry

4.1.1 G eneral

4.1.1.1 The eq uipment for the measurement of

for es and g eometry shal includ e

— an a le or spind le sup orting a rim on which

the ty re ma be rea iy mounted ,

— a test d rum, the a is of which is p ralel to said

a le,

— a means for load ing the ty re ag ainst the d rum

( or pushing the d rum ag ainst the ty re) at a

specified for e and/or for holding a fixed

ty re-to-d rum a is d istance d uring

measurements,

— equipment to measure the for e components in

the ra ial ( Z a is) and lateral ( Y a is) d irections

whie the ty re an the drum are rotated at

pres ribed spe d, and

— optionaly , means for ra id inflation an

deflation of the ty re an for control of inflation

pres ure during rotation

4.1.1.2 The p ralelsm of the two a es of rotation

shal be kept below

0,25mm/m when load ed with a rad ial for e

( Z a is) of10kN an a lateral for e of5 0N

ifthe a p ratus is eq uip ed with a test drum of

ty pe A ( prefer ed outer diameter8 4mm),

© BSI 0 -2 0

0,5mm/ m when loa ed with a ra ial for e

( Z a is) of4 kN an a lateral for e of2kN if the

a p ratus is eq uip ed with a test drum of ty pe B

( prefer ed outer diameter16 0mm)

NOT I is desira le that the p ralelism b twe n drum an

tyre a es b 0,1 mm/ m ma imum u der no lo d,when the

a solute v lues of lateral for e of et are made e ual, b

adjustng the fi ing ng le detector , in order to cor ect the er or

caused b a is p ralelism, intererence an fi ing acuracy of

the detector The outer surace of the drum ma b used as

reference in place of the drum a is

4.1.1.3 Rotational torq ue should prefera ly be

a pled fom the ty re a is; alternativ ely it ma be

f om the drum a is

There should be prov isions for both clockwise and

cou ter clockwise directions of rotation

4.1.1.4 The eq uipment shal be ca a le of rotating

ty res at a rotational f equency of at least10r/ min

an not hig her than25 r/ min during the

measuring operations

4.1.2 St ruct ural re onant fequencie

The sup orting structure and components of the

machine shal be so desig ned that the influence of

natural f eq uencies, within the measurement

f equency rang e, do s not alter the measured

p rameter more than10%

4.1.3 External vib at ions

Suficient isolation of the eq uipment shal be

prov id ed in ord er to minimise the influence of the

env ironment on measured p rameter

4.2 Test drum

4.2.1The prefer ed outer diameter of the drum are:

8 4mm for ty e A, and

1 6 0mm for ty pe B

NOT The actual sp cified outer diameter can b comprised

b twe n:

8 0mm an 10 0mm ( reference b ing8 4mm) for ty e A,

an

15 0mm an 17 0mm ( reference b ing16 0mm) for

ty eB

If other drum diameter are used, their cor elaton wih the

prefered diameter is to b checked

4.2.2 The ru -out of the outer sur ace of the drum,

as measured at a reference b nd, shal be les than

0,0 mm when using ty pe A test d rum, and

0,1mm when using ty pe B test drum

4.2.3 The u b lance of the test drum, which is

c itical in case for es are measured at the drum a is,

shal remain les than the v alues g iv en in Ta le 1

Ta le 1

4.2.4 The wid th of the d rum sur ace shal be g reater

than the fo tprint of the ty re tested

4.2.5 The drum shal be provid ed with a

hig h-fiction coar e-tex tured outer sur ace in order

to prev ent lateral for es g enerated during the

measurement f om causing the ty re to skid on the

d rum

4.3 Test rim

4.3.1 The rim width shal be eq ual to that of one of

the rims permit ed b ISO4 0 -1, ISO4 0 -2,

ISO420 -1, ISO420 -2, ISO424 -1, ISO424 -2,

ISO424 -3, ISO5 51-1, ISO5 51-2, ISO6 5 -1

and ISO6 5 -2, an prefera ly eq ual to the

measuring rim width

4.3.2 The specified diameter an the in er contour

of the test rim for the measurement of for es and / or

g eometry shal g eneral y conform to the stand rd

d iameter and contour, but some modifications of the

contour ma be req uired to faci tate mounting ,

d ismou ting and proper seating of the ty re bead s for

repeata le d ta

W he ls hav ing special contour for bead retention

( e.g h mps, etc.) shal be av oid ed

4.3.3 The rims shal be suficiently rig id to ensure

that deflection in any d irection at the bea seat,

when operating u d er load , is les than0,1 5mm

4.3.4 The rims shal hav e a peak-to-peak ru -out at

the bea seats, in both rad ial ( bea seat portion) and

a ial ( in er sur ace of flang e) directions, when

instaled with normal pi oting on the a p ratus, les

than the v alues g iv en in Ta le 2

Ta le 2

4.3.5 The diference in diameter on the two bead

seats of the test rim shal not exce d the v alues

g iv en in Ta le 3

Ta le 3

4.3.6 The bea seats shal be turned and polshed ;

the two suraces shal be sy mmetrical with respect

to the eq uatorial plane of the whe l within the

v alues g iv en in Ta le 4

Tes drum

Residual u b lanc of the tes drum

Static, kg ·mm Dynam ic, kg·mm

2

Equipm ent

Peak-to-peak ru -out

mm

Ty pe A d rum <0,0

Ty pe B d rum <0,1

Equipm ent

Dif r nc in diam ete

mm