ISO 5775-1

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
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Reference number
NATIONAL REGULATIONS.
ISO/DIS 5775-1:2022(E)
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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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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.

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

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

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

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

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

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

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