ISO 5775-1:2023

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

This document 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 tyres; - “beaded edge” tyres mounted on hooked bead rims. This document does not apply to tubular sew-up tyres and non-pneumatic tyres.

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

General Information

• Status: Published
• Publication Date: 27-Jul-2023
• 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: 6060 - International Standard published
• Start Date: 28-Jul-2023
• Due Date: 18-Feb-2023
• Completion Date: 28-Jul-2023

Relations

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

Overview - ISO 5775-1:2023 (Bicycle tyres and rims - Part 1)

ISO 5775-1:2023 specifies tyre designations and dimensions for pneumatic bicycle tyres, including clincher tyres (straight-side or crotchet-type rims), tubeless, tubeless‑ready (TLR), tube‑type, and beaded‑edge tyres for hooked‑bead rims. Published as the seventh edition in 2023, it updates definitions, symbols and marking requirements and replaces the 2014 edition. This part does not apply to tubular sew‑up tyres or non‑pneumatic tyres.

Keywords: ISO 5775-1:2023, bicycle tyres and rims, tyre designations, tyre dimensions, tubeless, tubeless-ready, clincher tyres

Key topics and technical requirements

• Tyre nomenclature and marking: Mandatory visible sidewall marking with the nominal size designation: Nominal section width (mm) – Nominal rim diameter code (mm). Old size markings may be added but must be distinct.
• Nominal section width and rim diameter code: Nominal section width is the tyre’s designated inflated section width (integer mm). Nominal rim diameter code corresponds to the rim bead seat diameter (see ISO 5775-2 for full table).
• Overall size designation: Optional overall diameter × overall width codes (tables map codes to actual mm values).
• Type markings: Tubeless tyres marked “TUBELESS” or “TL”; tubeless‑ready marked “TUBELESS READY” or “TLR”; tube‑type may be marked “TUBE TYPE”.
• Pressure marking: Maximum inflation pressure in kilopascals (kPa) in multiples of 10; PSI may be shown (converted from kPa and rounded down). Recommended maximum pressures for straight‑side rims are specified by nominal section width (e.g., 18–24 mm = 550 kPa, 25–29 mm = 500 kPa, etc.).
• Dimensional specifications and measurement methods: Design tyre dimensions, measurement rims, and measurement methods are defined to ensure consistent evaluation of section width, overall width, diameter and bead fit.
• Safety markings and features: Directional rotation arrows (optional), rim line indicators to confirm bead seating, and marking for tyres that must be mounted only on hooked/crotchet rims.

Practical applications - who uses this standard

• Tyre manufacturers and designers for consistent product specification, labelling and dimensional verification.
• Rim manufacturers for compatible rim dimensions and nominal rim diameter codes (see ISO 5775-2).
• Bicycle OEMs, retailers and mechanics to verify correct tyre‑rim pairing, inflation limits and safety markings.
• Test labs and certification bodies for conformity testing and quality control.
• Regulators and importers/exporters to ensure compliance with international trade and safety requirements.

Related standards

• ISO 5775-2:2021 - Bicycle tyres and rims - Part 2: Rims (nominal rim diameter codes and rim dimensions)
• ISO 4223-1 - Definitions of some terms used in the tyre industry (pneumatic tyres)

Using ISO 5775-1:2023 helps ensure tyre‑to‑rim compatibility, clear consumer labelling, safer inflation/usage practices and smoother international trade in bicycle components.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 5775-1
Seventh edition
2023-07
Bicycle tyres and rims —
Part 1:
Tyre designations and dimensions
Pneumatiques et jantes pour cycles —
Partie 1: Désignation et cotes des pneumatiques
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Symbols and abbreviated terms . 2
4 Clincher tyres mounted on straight side or crotchet type rims . 2
4.1 Tyre nomenclature . 2
4.2 Tyre size designation and marking . 3
4.2.1 General . 3
4.2.2 Nominal size designation. 3
4.2.3 Overall size designation . 4
4.2.4 Old size marking . 6
4.2.5 Other service characteristics . 6
4.2.6 Examples . 8
4.3 Tyre dimensions . 8
4.3.1 General . 8
4.3.2 Design tyre dimensions . 8
4.3.3 Tyre measurement method . 9
4.3.4 Dimensional specifications . 10
4.4 Recommended rim widths in use . 11
5 “Beaded edge” tyres mounted on hooked bead (HB) rims.12
5.1 General .12
5.2 Tyre designation .12
5.2.1 General .12
5.2.2 Tyre size designation .13
5.2.3 Preferred direction of rotation. 13
5.2.4 Example . 13
5.3 Tyre dimensions . 13
5.3.1 General .13
5.3.2 “Design tyre” dimensions . 13
5.3.3 Calculation of maximum tyre dimensions in service . 14
5.3.4 Determination of nominal overall diameter code . 14
5.3.5 Values. 15
5.4 Tyre dimension measurement method . 15
5.5 Tyres that can be mounted on both hooked bead (HB) and straight side rims .15
5.5.1 Tyre designation .15
5.5.2 Maximum tyre dimensions in service . 15
Annex A (informative) Old size marking .16
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 31, Tyres, rims and valves, Subcommittee
SC 10, Cycle, moped, motorcycle tyres and rims.
This seventh edition cancels and replaces the sixth edition (ISO 5775-1:2014), which has been
technically revised.
The main changes are as follows:
— new definitions have been added for clarification in Clause 3;
— the symbols and abbreviated terms have been revised in 3.2;
— new requirements have been added for clarification in Clause 4.
A list of all parts in the ISO 5775 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
INTERNATIONAL STANDARD ISO 5775-1:2023(E)
Bicycle tyres and rims —
Part 1:
Tyre designations and dimensions
1 Scope
This document 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 tyres;
— “beaded edge” tyres mounted on hooked bead rims.
This document does not apply to tubular sew-up tyres and non-pneumatic tyres.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. 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 5775-2:2021, Bicycle tyres and rims — Part 2: Rims
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4223-1, ISO 5775-2 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1.1
clincher tyre
tyre that has beads that lock onto the rim bead seat and/or rim hook when the tyre is inflated
3.1.1.1
tubeless tyre
TL
clincher tyre (3.1.1) that is functional without an inner tube or sealant to maintain inflation pressure
3.1.1.2
tubeless-ready tyre
TLR
clincher tyre (3.1.1) that is functional without an inner tube but requires sealant to maintain inflation
pressure
3.1.1.3
tube-type tyre
clincher tyre (3.1.1) that is only functional with an inner tube to maintain inflation pressure
3.1.2
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 3.1.1.1 to 3.1.1.3 may also be referred to as “open tubular tyre”
if the tread is glued or vulcanized onto a non-vulcanized casing
3.2 Symbols and abbreviated terms
D design overall diameter
design
D maximum overall diameter
O,max
R design rim width
design
R measuring rim width
m
S design section width
S minimum section width
min
S nominal section width
N
H design section height
design
W overall width
W maximum overall width
max
C crotchet type rim
SS straight-side type rim
TC tubeless crotchet type rim
TSS tubeless straight-side type rim
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 overall diameter (D )
O
4 measuring rim width (R )
m
5 specified rim diameter (D)
6 tread
7 sidewall
8 bead
9 rim
Figure 1 — Sections of a cycle tyre showing components and nomenclature
4.2 Tyre size designation and marking
4.2.1 General
Clincher tyres shall be marked with the nominal size designation in accordance with 4.2.2. The other
markings shall conform to 4.2.3 to 4.2.5.
4.2.2 Nominal size designation
4.2.2.1 General
The nominal size designation shall be indicated clearly visible on the side, even when the tyre is
mounted as follows:
Nominal section width – Nominal rim diameter code
4.2.2.2 Nominal section width
The nominal section width is the designated inflated section width, the tyre is designed to measure on
the design rim at maximum pressure. It shall be expressed in millimetres, as an integer number.
4.2.2.3 Nominal rim diameter code
The nominal rim diameter code reflects the nominal bead seat diameter of the rim, that the tyre is
designed for. It shall be expressed in millimetres.
NOTE Nominal rim diameter codes are in ISO 5775-2:2021, Table 2.
4.2.3 Overall size designation
4.2.3.1 General
If the tyre size is characterized by a corresponding overall size designation, the overall size shall be
designated as follows:
Overall diameter code × Overall width code
4.2.3.2 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
a)
622 29
a)
For nominal section width 50 and below, overall diameter code 28 is accepted.
4.2.3.3 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
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
TTaabbllee 22 ((ccoonnttiinnueuedd))
Overall width Overall width code
mm
26 1,00
27 1,05
28 1,10
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
TTaabbllee 22 ((ccoonnttiinnueuedd))
Overall width Overall width code
mm
69 2,70
70 2,80
71 2,80
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
127 5,00
130 5,10
132 5,20
4.2.4 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 nominal size designation specified in
4.2.2 be adopted. See Annex A for correspondence between “nominal size designation” and “old size
marking”. Sizes not included in Annex A shall bear the nominal size designation.
4.2.5 Other service characteristics
4.2.5.1 Tubeless marking
Tubeless tyres shall be marked with “TUBELESS” or “TL” clearly visible on the side, even when the tyre
is mounted.
Tubeless-ready tyres shall be marked with “TUBELESS READY” or “TLR” clearly visible on the side,
even when the tyre is mounted.
Tube-type tyres may be marked with “TUBE TYPE” clearly visible on the side, even when the tyre is
mounted.
4.2.5.2 Directional arrow
In the case of a preferred direction of rotation of the tyre, an arrow may be shown clearly visible on the
side, even when the tyre is mounted, to indicate that direction.
4.2.5.3 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”.
4.2.5.4 Pressure des
...