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.
