Skip to content
Technical Reference

Bicycle Standards Directory: ISO, ETRTO, EN, CPSC

By Cycle99 Editorial Team ⏱ 8 min read 📂 Technical Reference

Short answer: four bodies matter most when you read a bicycle spec sheet. ISO writes the international safety, tire and terminology standards, CEN adopts and extends them in Europe (as EN or EN ISO), ETRTO coordinates tire, rim and valve interchangeability, and the US Consumer Product Safety Commission (CPSC) enforces a federal regulation, 16 CFR Part 1512, for bicycles sold in the United States. This directory summarizes the scope of each, in our own words. Full standard texts are copyrighted and sold by the publishers, so we describe what each covers and where to buy it, not what it says line by line.

At a glance

Document Issued by What it covers Status
ISO 4210-1:2023 ISO Vocabulary for the series Current (Jan 2023)
ISO 4210-2:2023 ISO Requirements for city and trekking, young adult, mountain and racing bicycles Current (11 Jan 2023); replaced the 2015 edition
ISO 4210-3:2023 ISO Common test methods Current (Jan 2023)
ISO 4210-4 ISO Braking test methods Part of the current series; confirm the edition with ISO or your national body
ISO 4210-5 ISO Steering test methods Part of the current series; confirm the edition with ISO or your national body
ISO 4210-6:2023 ISO Frame and fork test methods Current (Jan 2023, corrected version Aug 2023)
ISO 4210-7:2023 ISO Wheel and rim test methods Current (Jan 2023)
ISO 4210-8:2023 ISO Pedal and drive system test methods Current (Jan 2023); replaced the 2014 edition
ISO 4210-9:2023 ISO Saddle and seat-post test methods Current (Jan 2023); replaced the 2014 edition
ISO 8098:2023 (EN ISO 8098:2023) ISO / CEN Safety requirements for bicycles for young children (saddle height above 435 mm and below 635 mm) Current (2023); replaced 2014 edition
ISO 5775-1:2023 ISO Bicycle tire designations and dimensions 2023 edition listed as current; replaced the 2014 edition
ISO 5775-2:2021 ISO Bicycle rims (straight-side, hooked-bead and crotchet types) Current edition (2021)
ISO 8090:2019 ISO Terminology for cycles and EPACs Current edition
EN 15194:2017+A1:2023 CEN Electrically power assisted cycles (EPACs, or pedelecs) Published; CEN record shows it under revision (prEN 15194 in development). Base EN 15194:2017 is superseded by the A1 version
EN 50604-1:2016+A1:2021 CENELEC Safety requirements and tests for secondary lithium batteries in light electric vehicles Valid per SIS listing; check for later amendments
UL 2849 UL (US/Canada) Electrical system of e-bikes: drive unit, battery, battery management, wiring, charger Confirm the current edition with UL
ETRTO Standards Manual ETRTO Interchangeability of pneumatic tires, rims and valves Publisher standards manual; confirm bicycle coverage before buying
16 CFR Part 1512 US CPSC Federal requirements for bicycles sold in the US In force (federal regulation)

All texts except 16 CFR Part 1512 are paid. Status reflects publisher catalogue listings as of October 2026; standards are revised, so confirm the current edition with the publisher or your national standards body before citing one.

First, what a standard is (and is not)

A standard is a consensus document: committees of manufacturers, test labs and regulators agree on definitions, dimensions and test methods. Following one is usually voluntary unless a law points to it. A regulation is law. In the EU, a standard can become the accepted way to show a product meets a legal requirement; in the US, the CPSC regulation is mandatory for covered bicycles. A label such as “tested to ISO 4210” is a claim by the maker. It is not a guarantee of quality, and it tells you nothing about how a particular bike was tested unless a test report is available.

ISO 4210: the bicycle safety series

ISO 4210 is the main international safety standard for bicycles. It is published in several parts. Two are worth knowing by number:

  • ISO 4210-2:2023 sets safety and performance requirements for the design, assembly and testing of bicycles and their sub-assemblies, and gives guidance on the manufacturer’s instructions for use and care. As listed by Austrian Standards, its scope is young adult bicycles (maximum saddle height of 635 mm to under 750 mm), plus city and trekking, mountain and racing bicycles with a maximum saddle height of 635 mm or more, folding bicycles included. It excludes delivery bicycles, recumbents, tandems and BMX bicycles, and bicycles built for severe use such as sanctioned competition, stunting or aerobatics.
  • ISO 4210-3:2023 holds the common test methods the other parts refer to.
  • The remaining parts are Part 1 (vocabulary) and Parts 4 to 9, which give test methods for braking, steering, frame and fork, wheels and rims, pedals and drive system, and saddles and seat posts. All appear in the table above.

The standard is adopted in Europe as EN ISO 4210, so one document serves both labels. Smaller bicycles fall elsewhere: the ISO 4210-2 scope points to ISO 8098:2023 (bicycles for young children) for saddle heights between 435 mm and 635 mm and to national ride-on toy rules for 435 mm or less. See our guide to cycling with kids for practical context on child equipment.

We have not reproduced requirements or test values. Anyone relying on a specific figure should buy the standard from ISO, BSI or their national body.

EN 15194: electric bikes in Europe

EN 15194 is the European standard for EPACs (electrically power assisted cycles, commonly called pedelecs). Its scope is built around a continuous rated power of 0.25 kW (250 W) whose assistance is progressively reduced and cut off at 25 km/h, or sooner if the rider stops pedaling. It covers significant hazards including reasonably foreseeable misuse, and addresses electrical circuits and charging for lower-voltage systems; battery safety is handled through the separate battery standard EN 50604-1 listed above. EN 15194:2017+A1:2023 is the edition listed by the Dutch NEN catalogue, and the CEN project record (as mirrored by Genorma) shows it as published and slated for revision, with prEN 15194 in development. The older base EN 15194:2017 is superseded by the A1:2023 version. Because a revision is in progress, check the CEN catalogue and your national body before citing the edition.

This standard describes a product category. It does not tell you what is legal where you ride: speed and power limits, throttles and age rules are set by national or state law. Our e-bike laws guide covers that, and throttle vs pedal assist explains why the distinction matters. Never modify an e-bike to defeat its speed limiter; doing so can take it outside the category it was certified in.

ISO 5775 and ETRTO: why tires and rims fit

Tire and rim sizing is where standards touch most riders. The problem they solve is interchangeability: a tire from one maker must seat safely on a rim from another.

  • ISO 5775-1:2023 covers designations and dimensions of pneumatic bicycle tires, including clincher tires on straight-side or crochet rims, tubeless and tubeless-ready tires, tube-type tires, and beaded-edge tires on hooked-bead rims. It excludes tubular (sew-up) tires and non-pneumatic tires. The 2023 edition replaced the 2014 edition. Its companion, ISO 5775-2:2021, covers straight-side, hooked-bead and crotchet rims; the 2021 edition is the current published one.
  • ETRTO (the European Tyre and Rim Technical Organisation, based in Brussels) states its aim as alignment of national standards to achieve interchangeability of pneumatic tires, rims and valves. It publishes a Standards Manual; confirm in the manual itself that it covers the bicycle sizes you need before buying.

The practical result is the two-part size printed on a sidewall, for example a width and a bead seat diameter in millimeters. Match both numbers to your rim, and note that rim width limits the safe tire width range. We walk through this in tire pressure and gravel tires explained. We have not reproduced the designation tables; if a fit question is safety-critical, such as a tubeless setup on an unfamiliar rim, check the rim and tire manufacturers’ stated compatibility.

ISO 8090: the shared vocabulary

ISO 8090:2019 defines common terms and symbols for bicycles and EPACs, grouped by vehicle part and presented in several languages. It replaced the 1990 edition. A new edition may appear in future. Its value is consistency: terms such as “pedelec” or “EPAC” mean one thing across documents.

US CPSC 16 CFR Part 1512

In the United States, Part 1512 is a federal regulation, and unlike the voluntary standards above it is free to read on the eCFR. Section 1512.2(a) defines a bicycle as a two-wheeled vehicle having a rear drive wheel that is solely human-powered, or a two- or three-wheeled vehicle with fully operable pedals and an electric motor of less than 750 watts (1 h.p.) whose maximum speed on a paved level surface, powered solely by the motor and ridden by an operator who weighs 170 pounds, is less than 20 mph. Section 1512.1 (scope) excludes track bicycles and one-of-a-kind bicycles, as defined in 1512.2(d) and (e), and bicycles that are banned articles under 16 CFR 1500.18(a)(12). A bicycle must comply in the condition in which it is offered for sale, or, if sold partly assembled, after assembly per the manufacturer’s instructions.

The section headings after the general requirements in 1512.3 give a map of what is regulated:

  • 1512.4 mechanical requirements, 1512.5 braking system, 1512.6 steering system
  • 1512.7 pedals, 1512.8 drive chain, 1512.9 protective guards
  • 1512.10 tires, 1512.11 wheels, 1512.12 wheel hubs
  • 1512.13 front fork, 1512.14 fork and frame assembly, 1512.15 seat
  • 1512.16 reflectors, 1512.17 other requirements, 1512.18 tests and test procedures, 1512.19 instructions and labeling, 1512.20 separability

Whether a specific e-bike falls under Part 1512 or other rules depends on its motor power and top speed; check the regulation text and the manufacturer’s documentation. Reflector requirements here are the reason new bikes ship with reflectors; for what you should add on top, see our lights buyer’s guide.

How to use this in practice

  1. Find the claim. Look for the standard named in the manual or spec page. Vague wording like “meets safety standards” is not a claim you can check.
  2. Match the standard to the product. ISO 4210-2 excludes tandems, BMX and recumbents, so a mention on those would deserve a question.
  3. Check the edition. Standards are revised; a 2014-era citation may not reflect current requirements.
  4. Treat standards as a floor. Passing tests does not replace correct assembly, maintenance or inspection. Stop riding and see a professional mechanic for any cracked frame, fork, handlebar or wheel, brakes that do not stop the bike, or an e-bike battery that is swollen, hot or damaged. Do not ride with damaged structural parts.

For the maintenance side, our pre-ride checklist is the place to start.

Sources

Last reviewed: October 2026.

More in Technical Reference