ISO 5775-1

Bicycle tyres and rims — Part 1: Tyre designations and dimensions

Pneumatiques et jantes pour cycles — Partie 1: Désignation et cotes des pneumatiques

General Information

• Status: Not Published
• ICS: 83.160.10 - Road vehicle tyres
• Technical Committee: ISO/TC 31/SC 10 - Cycle, moped, motorcycle tyres and rims
• Drafting Committee: ISO/TC 31/SC 10/WG 16 - Tyre designations and dimensions for Bicycle tyres and rims
• Current Stage: 6000 - International Standard under publication
• Completion Date: 01-Jun-2023

Relations

• Revises: ISO 5775-1:2014 - Bicycle tyres and rims — Part 1: Tyre designations and dimensions
• Effective Date: 23-Apr-2020

Standards Content (Sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 5775-1
ISO/TC 31/SC 10 Secretariat: UNI
Voting begins on: Voting terminates on:
2022-10-12 2023-01-04
Bicycle tyres and rims —
Part 1:
Tyre designations and dimensions
Pneumatiques et jantes pour cycles —
Partie 1: Désignation et cotes des pneumatiques
ICS: 83.160.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 5775-1:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
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ISO/DIS 5775-1:2022(E)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 5775-1
ISO/TC 31/SC 10 Secretariat: UNI
Voting begins on: Voting terminates on:
Bicycle tyres and rims —
Part 1:
Tyre designations and dimensions
Pneumatiques et jantes pour cycles —
Partie 1: Désignation et cotes des pneumatiques
ICS: 83.160.10
COPYRIGHT PROTECTED DOCUMENT
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
© ISO 2022
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

NOT BE REFERRED TO AS AN INTERNATIONAL

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on STANDARD UNTIL PUBLISHED AS SUCH.

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

IN ADDITION TO THEIR EVALUATION AS

or ISO’s member body in the country of the requester. BEING ACCEPTABLE FOR INDUSTRIAL,

TECHNOLOGICAL, COMMERCIAL AND
ISO copyright office
USER PURPOSES, DRAFT INTERNATIONAL
CP 401 • Ch. de Blandonnet 8
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
CH-1214 Vernier, Geneva
POTENTIAL TO BECOME STANDARDS TO
Phone: [phone]
WHICH REFERENCE MAY BE MADE IN
Reference number
Email: [e-mail]
NATIONAL REGULATIONS.
Website: www.iso.org ISO/DIS 5775-1:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
Published in Switzerland
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
© ISO 2022 – All rights reserved
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
---------------------- Page: 2 ----------------------
ISO/DIS 5775-1:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Clincher tyres mounted on straight side or crotchet type rims ........................................................................ 2

4.1 Tyre nomenclature .............................................................................................................................................................................. 2

4.2 Tire size designation and marking ....................................................................................................................................... 2

4.2.1 Nominal size designation............................................................................................................................................ 2

4.2.2 Overall size designation ............................................................................................................................................... 3

4.2.3 Old size marking ................................................................................................................................................................. 5

4.2.4 Other service characteristics .................................................................................................................................. 5

4.2.5 Examples ................................................................................................................................................................................... 7

4.3 Tyre dimensions .................................................................................................................................................................................... 7

4.3.1 Design tyre dimensions ............................................................................................................................................... 7

4.3.2 Tyre measurement method ....................................................................................................................................... 9

4.3.3 Dimensional specifications ....................................................................................................................................... 9

4.4 Recommended rim widths in use ....................................................................................................................................... 10

5 “Beaded edge” tyres mounted on hooked bead (HB) rims...................................................................................12

5.1 Tyre designation ................................................................................................................................................................................ 13

5.1.1 Tyre size designation ...................................................................................................................................................13

5.1.2 Preferred direction of rotation........................................................................................................................... 13

5.1.3 Example ...................................................................................................................................................................................13

5.2 Tyre dimensions ................................................................................................................................................................................. 13

5.2.1 “Design tyre” dimensions ........................................................................................................................................ 13

5.2.2 Calculation of maximum tyre dimensions in service ..................................................................... 14

5.2.3 Determination of nominal overall diameter code ............................................................................. 14

5.2.4 Values......................................................................................................................................................................................... 15

5.3 Tyre dimension measurement method .......................................................................................................................... 15

5.4 Tyres than can be mounted on both hooked bead (HB) and straight side rims .......................15

5.4.1 Tyre designation .............................................................................................................................................................. 15

5.4.2 Maximum tyre dimensions in service .......................................................................................................... 15

Annex A (informative) Old size marking ......................................................................................................................................................16

iii
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ISO/DIS 5775-1:2022(E)
Foreword
The main changes compared to the previous edition are as follows:
— new definitions have been added for clarification in Clause 3;
— new requirements have been added for clarification in Clause 4;
— the symbols and abbreviated terms have been revised in Clause 4;
© ISO 2022 – All rights reserved
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DRAFT INTERNATIONAL STANDARD ISO/DIS 5775-1:2022(E)
Bicycle tyres and rims —
Part 1:
Tyre designations and dimensions
1 Scope

This part of ISO 5775 specifies the designations and dimensions for the following pneumatic bicycle

tyres:
— Clincher tyres mounted on straight side or crotchet type rims
— Tubeless tyres
— Tubeless-ready tyres
— Tube-type
— “beaded edge” tyres mounted on hooked bead rims.

Tubular sew-up tyres and non-pneumatic tyres are not covered by this part of ISO 5775.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 4223-1, Definitions of some terms used in the tyre industry — Part 1: Pneumatic tyres

ISO 5775-2, Bicycle tyres and rims — Part 2: Rims
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 4223-1 and ISO 5775-2 and

the following apply.
3.1
clincher tyre

tyre that has beads that lock onto the rim bead seat and/or rim hook when the tyre is inflated

3.1.1
tubeless tyre (TL)

clincher tyre (3.1) that is functional without an inner tube or sealant to maintain inflation pressure

3.1.2
tubeless-ready tyre (TLR)

clincher tyre (3.1) that is functional without and inner tube but requires sealant to maintain inflation

pressure
3.1.3
tube-type tyre

clincher tyre (3.1) that is only functional with an inner tube to maintain inflation pressure

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ISO/DIS 5775-1:2022(E)
3.2
tubular sew-up tyre

completely enclosed tyre with or without an inner tube that is either glued or taped onto the rim.

Note 1 to entry: All clincher tyre types defined in 3.1.1 to 3.1.3 may also be referred to as “open tubular tyre” if

the tread is glued or vulcanized onto a non-vulcanized casing
4 Clincher tyres mounted on straight side or crotchet type rims
4.1 Tyre nomenclature
Tyre nomenclature is shown in Figure 1.
Key
1 overall width (W)
2 section width (S)
3 maximum overall diameter (D )
4 measuring rim width (R )
5 specified rim diameter (D)
6 tread
7 side wall
8 bead
9 rim
Figure 1 — Sections of a cycle tyre showing components and nomenclature
4.2 Tire size designation and marking

Clincher tyres shall be marked with the nominal size designation pursuant to 4.2.1. The other markings

shall comply with 4.2.2. through 4.2.4.
4.2.1 Nominal size designation
The nominal size designation shall be indicated as follows:
Nominal Section Width – Nominal Rim Diameter Code
4.2.1.1 Nominal section width

The nominal section width is the designated inflated section width the tire is designed to measure on

the design rim at maximum pressure. It shall be expressed in millimetres, as an integer number.

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ISO/DIS 5775-1:2022(E)
4.2.1.2 Nominal rim diameter code

The nominal rim diameter code reflects the nominal bead seat diameter of the rim that the tire is

designed for. It shall be expressed in millimetres.
NOTE Nominal rim diameter codes are in Table 2 of ISO 5775-2.
4.2.2 Overall size designation

If the tyre size is characterized by a corresponding overall size designation, the overall size shall be

designated as follows:
Overall Diameter Code x Overall Width Code
4.2.2.1 Overall diameter code

The overall diameter shall be expressed as code. Refer to Table 1 for the overall diameter code that

corresponds to the nominal rim diameter code of the tyre.
Table 1 — Correspondence of nominal rim diameter code and overall diameter code
Nominal rim diameter code Overall diameter code
203 12,5
254 14
305 16
349 16
355 18
406 20
507 24
559 26
584 27,5
622 29
4.2.2.2 Overall width code

The overall width shall be expressed as code. Refer to Table 2 for the correspondence of overall width

code to the overall width expressed in millimetres.
Table 2 — Overall width code
Overall width Overall width code
in mm
18 0,70
19 0,75
20 0,80
21 0,85
22 0,85
23 0,90
24 0,95
25 1,00
26 1,00
27 1,05
28 1,10
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ISO/DIS 5775-1:2022(E)
Table 2 (continued)
Overall width Overall width code
in mm
29 1,15
30 1,20
31 1,20
32 1,25
33 1,30
34 1,35
35 1,40
36 1,40
37 1,45
38 1,50
39 1,55
40 1,55
41 1,60
42 1,65
43 1,70
44 1,75
45 1,75
46 1,80
47 1,85
48 1,90
49 1,95
50 2,00
51 2,00
52 2,00
53 2,10
54 2,10
55 2,20
56 2,20
57 2,20
58 2,30
59 2,30
60 2,40
61 2,40
62 2,40
63 2,50
64 2,50
65 2,60
66 2,60
67 2,60
68 2,70
69 2,70
70 2,80
71 2,80
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ISO/DIS 5775-1:2022(E)
Table 2 (continued)
Overall width Overall width code
in mm
75 3,00
76 3,00
80 3,10
85 3,30
90 3,50
95 3,70
100 3,90
102 4,00
105 4,10
110 4,30
115 4,50
120 4,70
122 4,80
125 4,90
130 5,10
132 5,20
4.2.3 Old size marking

To help customers in those Countries where other systems of marking were used, the old size marking

may be separated by parentheses or "/" before or after the tyre size designation.

It is suggested that characters smaller than those used for the designation specified in 4.2.1 be adopted.

See informative Annex A for correspondence between “tyre size designation” and “old size marking”.

Sizes not included in Annex A shall bear the tyre size designation and corresponding nominal size.

4.2.4 Other service characteristics
4.2.4.1 Tubeless marking
Tubeless tyre shall be marked with “TUBELESS” or “TL” on the tyre sidewall.

Tubeless-ready tyre shall be marked with “TUBELESS READY” or “TLR” on the tyre sidewall.

Tube-type tyre may be marked with “TUBE TYPE” on the tyre sidewall.
4.2.4.2 Directional arrow

In the case of a preferred direction of rotation of the tyre, an arrow may be shown on the tyre sidewall

to indicate that direction.
4.2.4.3 Marking of tyres designed for crotchet-type rims only

Tyres designed for crotchet-type rims only may be marked with "MOUNT ONLY ON HOOKED RIMS" or

"MOUNT ONLY ON CROTCHET-TYPE RIMS".
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ISO/DIS 5775-1:2022(E)
4.2.4.4 Pressure designation

The maximum inflation pressure shall be marked in kilopascals in multiples of 10. It may be marked in

addition in bars and PSI where the PSI value shall be calculated by multiplying the kilopascal value by

0,145 and rounding the result down to the closest integer.

An additional maximum pressure for use on straight side type rims (SS/TSS) may be indicated. See

Table 3 for recommended maximum pressures for straight side type rims.
Table 3 — Maximum pressure for straight side type rims (SS/TSS)
Tyre Nominal section width S Straight side type rim maximum pressure in
(mm) service (kPa)
18 – 24 550
25 – 29 500
30 – 34 450
35 – 39 400
40 – 44 350
45 – 54 300
55 – 64 250
65 – 74 200
75 – 84 150

It is recommended that the deflection of the tyre in use not exceed 30 % of the tyre section height at the

minimum inflation pressure, if it is specified on the tyre.
See example in 4.2.5.
4.2.4.5 Rim line

The rim line is an indicator that may be visible and concentric above the rim sidewall when the beads

are fully seated (see Figure 2). If the rim line is not concentric with the rim edge, the bead is not fully

seated.
Key
1 rim line
Figure 2 — Rim line
4.2.4.6 Additional indications
Other markings may be added to indicate the following:
a) Minimum inflation pressure
b) Recommended inflation pressure
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ISO/DIS 5775-1:2022(E)
c) Design rim
d) Recommended rim width range
e) Other characteristics
4.2.5 Examples
A tyre
...