CEN/TR 17112:2017

Cycles - Composite material used in bicycles - Specific tests suitable for components manufactured from composite materials

The purpose of this Technical Report is to provide innovative requirements and test methods applicable to any category of bicycle (city/trekking, MTB, young adult and racing) containing components manufactured, in part or whole, from composite materials. Its aim is to provide technical solutions that reduce the risk of component failure and rider injury during the specified use of such bicycles.
This Technical Report includes requirements and test methods validated by the bicycle industry and test houses for composite assemblies including forks, frames, wheels, saddle rails and seat posts.
This Technical Report makes reference to current "state of the art" standards in the field of bicycles, agreed at CEN level through the publication of EN ISO 4210  series of standards. Therefore, the requirements and tests proposed in this Technical Report are intended to be read and applied in accordance with the appropriate EN ISO 4210 standard.
NOTE   Please note that the tests described in this TR refer in places to paragraph numbers from the applicable EN ISO 4210  series.

Fahrräder - Verbundwerkstoffe für Fahrräder - Spezifische Prüfverfahren für aus Verbundwerkstoffe hergestellte Komponenten

Cycles - Matériaux composites utilisés dans les bicyclettes - Essais spécifiques adaptés aux composants fabriqués à partir de matériaux composites

Kolesa - Kompozitni materiali za kolesa - Posebni preskusi za sestavne dele iz kompozitnih materialov

Namen tega tehničnega poročila je opredelitev inovativnih zahtev in preskusnih metod, ki se uporabljajo za katero koli kategorijo koles (mestna/treking kolesa, gorska kolesa, kolesa za mladino in tekmovalna kolesa) s sestavnimi deli, ki so delno ali v celoti izdelani iz kompozitnih materialov. Cilj je podati tehnične rešitve, ki zmanjšujejo nevarnost okvar sestavnih delov in telesnih poškodb kolesarjev pri določeni uporabi takšnih koles.
To tehnično poročilo vključuje zahteve in preskusne metode, overjene v panogi koles in preskusnih ustanovah za kompozitne sestavne dele, vključno z vilicami, okvirji, kolesi ter sedežnimi nastavki in drogovi.
To tehnično poročilo se sklicuje na trenutne standarde za »stanje tehnike« na področju koles, sprejete na ravni CEN v okviru objave skupine standardov EN ISO 4210. Zahteve in preskusi, ki jih podaja to tehnično poročilo, so namenjeni za branje in uporabo v skladu z ustreznim standardom EN ISO 4210.
OPOMBA:Preskusi, opisani v tem tehničnem poročilu, se na nekaterih mestih sklicujejo na številke odstavkov ustrezne skupine standardov EN ISO 4210.

General Information

• Status: Published
• Publication Date: 11-Jul-2017
• ICS: 43.150 - Cycles
• Technical Committee: CEN/TC 333 - Cycles
• Drafting Committee: CEN/TC 333/WG 8 - Composite material used in bicycles
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 12-Jul-2017
• Due Date: 01-Jan-2018
• Completion Date: 12-Jul-2017
• Ref Project: SIST-TP CEN/TR 17112:2017 - Cycles - Composite material used in bicycles - Specific tests suitable for components manufactured from composite materials

Overview

CEN/TR 17112:2017 - "Cycles - Composite material used in bicycles - Specific tests suitable for components manufactured from composite materials" - is a CEN Technical Report that defines validated test methods and requirements for bicycle components made partly or wholly from composite materials. It covers composite assemblies such as forks (steerer tubes), frames, wheels (tubular and clincher), composite wheels, saddle rails and composite seat posts, with the objective of reducing component failure and rider injury during normal and specified use.

This TR is intended to be read and applied in conjunction with the EN ISO 4210 series (bicycle safety and test methods) and references specific paragraphs from those standards where applicable.

Key topics and requirements

• Steerer tube fatigue test
  • Assembly-level fatigue testing of stem plus composite steerer to verify compatibility.
  • No visible cracks or fractures after testing; running displacement increase limited to ≤ 20% of initial values for composite fork steerers.
  • Typical test stop criterion: 20 000 cycles; loads referenced (e.g., 400 N per end or 800 N with dummy clamp) and stem torque per manufacturer spec.
• Heat resistance testing for composite wheels
  • Addresses rim brake heat exposure which can damage composite resin (TG considerations), brake pads and rim sidewalls.
  • Two-stage testing for rim brake systems with composite rims: a brake heat cycle followed by wheel tests; criteria include no visible cracking, limited permanent width increase (≤ 5%) and lateral/radial runout limits (≤ 1.0 mm).
  • Braking energy targets given per bicycle category (e.g., 55 Wh for city/trekking, 75 Wh for mountain/racing).
• Impact-after-heat and wheel impact tests
  • After heat-resistance cycles, composite rims undergo impact tests (e.g., ~40 J impact) and must show no cracks and acceptable runout.
• Saddle rail and seat post tests
  • Specific fatigue and static tests for composite saddle rails and seat posts referenced to EN ISO 4210 methods; requirements ensure structural integrity under expected loading.

Practical applications

• Product validation and R&D for manufacturers of composite forks, frames, wheels, saddle systems and seat posts.
• Type testing by independent test houses and quality assurance labs to verify compliance and reduce risk of in-service failures.
• Design guidance for material selection (resin TG, pad compatibility) and component compatibility (stem–steerer assemblies).
• Safety and certification reference for OEMs, component suppliers and bicycle safety engineers.

Who should use this TR

• Bicycle manufacturers, composite component designers, test laboratories, compliance officers, and standards committees working with composite bicycle components and wheel brake systems.

Related standards

• EN ISO 4210 series (safety requirements and common test methods) - specifically Parts 2, 3, 4, 5, 6, 7 and 9 are referenced throughout CEN/TR 17112:2017.

Keywords: CEN/TR 17112:2017, composite bicycle components, composite wheels, steerer tube fatigue test, heat resistance testing, EN ISO 4210.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2017
Kolesa - Kompozitni materiali za kolesa - Posebni preskusi za sestavne dele iz
kompozitnih materialov
Cycles - Composite material used in bicycles - Specific tests suitable for components
manufactured from composite materials
Fahrräder - Verbundwerkstoffe für Fahrräder - Spezifische Prüfverfahren für aus
Verbundwerkstoffe hergestellte Komponenten
Ta slovenski standard je istoveten z: CEN/TR 17112:2017
ICS:
43.150 Kolesa Cycles
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TR 17112
TECHNICAL REPORT
RAPPORT TECHNIQUE
July 2017
TECHNISCHER BERICHT
ICS 43.150
English Version
Cycles - Composite material used in bicycles - Specific tests
suitable for components manufactured from composite
materials
Cycles - Matériaux composites utilisés dans les Fahrräder - Verbundwerkstoffe für Fahrräder -
bicyclettes - Essais spécifiques adaptés aux Spezifische Prüfverfahren für aus Verbundwerkstoffe
composants fabriqués à partir de matériaux hergestellte Komponenten
composites
This Technical Report was approved by CEN on 26 June 2017. It has been drawn up by the Technical Committee CEN/TC 333.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 17112:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Steerer tube fatigue test . 4
3.1 General . 4
3.2 Background . 4
3.3 Requirements . 5
3.4 Test methods - Addition. 5
4 Heat resistance testing for composite wheels . 6
4.1 Background . 6
4.2 Requirements . 6
4.3 Test methods . 7
5 Composite saddle rail test . 10
5.1 General . 10
5.2 Background . 10
5.3 Requirements . 10
5.4 Test methods . 11
6 Composite seat post fatigue testing . 12
6.1 General . 12
6.2 Background . 12
6.3 Test methods . 12

European foreword
This document (CEN/TR 17112:2017) has been prepared by Technical Committee CEN/TC 333
“Cycles”, the secretariat of which is held by UNI.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
1 Scope
The purpose of this Technical Report is to provide innovative requirements and test methods applicable
to any category of bicycle (city/trekking, MTB, young adult and racing) containing components
manufactured, in part or whole, from composite materials. Its aim is to provide technical solutions that
reduce the risk of component failure and rider injury during the specified use of such bicycles.
This Technical Report includes requirements and test methods validated by the bicycle industry and
test houses for composite assemblies including forks, frames, wheels, saddle rails and seat posts.
This Technical Report makes reference to current “state of the art” standards in the field of bicycles,
agreed at CEN level through the publication of EN ISO 4210- series of standards. Therefore, the
requirements and tests proposed in this Technical Report are intended to be read and applied in
accordance with the appropriate EN ISO 4210 standard.
NOTE Please note that the tests described in this TR refer in places to paragraph numbers from the
applicable EN ISO 4210- series.
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.
EN ISO 4210-2:2015, Cycles - Safety requirements for bicycles - Part 2: Requirements for city and trekking,
young adult, mountain and racing bicycles (ISO 4210-2:2015)
EN ISO 4210-3:2014, Cycles - Safety requirements for bicycles - Part 3: Common test methods (ISO 4210-
3:2014)
EN ISO 4210-4:2014, Cycles - Safety requirements for bicycles - Part 4: Braking test methods (ISO 4210-
4:2014)
EN ISO 4210-5:2014, Cycles - Safety requirements for bicycles - Part 5: Steering test methods (ISO 4210-
5:2014, Corrected version 2015-02-01)
EN ISO 4210-6:2015, Cycles - Safety requirements for bicycles - Part 6: Frame and fork test methods (ISO
4210-6:2015)
EN ISO 4210-7:2014, Cycles - Safety requirements for bicycles - Part 7: Wheels and rims test methods (ISO
4210-7:2014)
EN ISO 4210-9:2014, Cycles - Safety requirements for bicycles - Part 9: Saddles and seat-post test methods
(ISO 4210-9:2014)
3 Steerer tube fatigue test
3.1 General
To apply this test, EN ISO 4210-2:2015 and EN ISO 4210-6:2015 shall be used.
3.2 Background
The proposal for a fork steerer tube fatigue test was developed due to several professional and
numerous consumer accidents that involved the fatigue failure of composite material steerer tubes. The
cycle industry has developed a test to confirm stem and steerer tube compatibility as an assembly. Note
that the combination of specified handlebar stems and composite fork steerers can have an effect on the
integrity of the product. This test has now been utilized for more than 8 years by some manufacturers
as part of their internal validation testing.
3.3 Requirements
When tested by the method described in 5.8.2.1, there shall be no fractures or visible cracks in any part
of the fork. This shall be confirmed by removing the steering assembly and inspecting the fork steerer.
The running displacements (peak-to-peak value) at the points where the test forces are applied shall
not increase by more than 20 % of the initial values for a composite fork.
3.4 Test methods - Addition
EN ISO 4210-6:2015, 5.8 Fork Steerer Tube and Stem Assembly - Fatigue Test
5.8.1 General
A bicycle fork shall be subjected to in-phase fatigue loading via a stem or a handlebar stem assembly
attached at the steerer tube in the direction parallel to the fork steerer tube. The test shall be used to
qualify the fork system, including the specified stem, expander nut, and headset assembly (top-cap,
bearings, etc.). The headset spacers shall be removed and the stem shall contact the top cap of the
headset. The stem fasteners shall be torqued to the manufacturers recommended maximum
specification. If the intended stem type is known, the maximum specified length shall be used for this
test.
5.8.2 Fork Steerer Tube Fatigue Test
5.8.2.1 Fork Steerer Tube Fatigue Test Method
The loading conditions are the same as EN ISO 4210-5:2014, 4.9.2.2 handlebar fatigue In-Phase
procedure (phase 2). If a handlebar and stem assembly is used for testing, 400 N (F) shall be applied
fully reversed to each end of the ball joint attachment. The maximum test frequency shall be
maintained as specified in EN ISO 4210-3:2014, 4.5. In the case where the specified stem is known but
not the handlebar, a dummy load arm shall be used and adjusted for length based on the manufacturer's
specifications (minimum value of 110 mm - X). A load of 800 N (F) shall be applied fully reversed to the
dummy clamp (see Figure 1). For composite fork steerer tubes, the running displacements (peak-to-
peak value) at the points where the test forces are applied shall not increase by more than 20 % of the
initial values. Stop the test after 20 000 cycles, remove the stem assembly and inspect the fork assembly
for cracks or fractures.
Key
X length
F applied load
Figure 1 — Dummy clamp
4 Heat resistance testing for composite wheels
4.1 Background
There has been some concern in the development of composite wheels (tubular or clincher rims) that
excessive heat generated during extreme braking (long decents or turning during decents) can cause
material damage that may lead to structural damage of the rim. The resin’s TG (glass transition
temperature) plays a large part in this, but also the braking force and brake pad compound factor in.
Impact after heat damage can also cause structural damage to wheel components. We feel that a review
and test requirement/proposal is a good direction forward to establishing a safety standard that can be
incorporated into an EN and/or ISO standard.
4.2 Requirements
EN ISO 4210-2:2015, 4.6.9 Brakes – Heat resistance test:
4.6.9.1 General
This test applies to all disc and hub brakes, but it applies to rim brakes where the brake pads are known
or suspected to be manufactured from or include thermoplastic materials. This test applies also to rim
brakes where the rim brake sidewalls are known or suspected to be manufactured from or include
composite materials.
Each brake on the bicycle shall be tested individually, but where the front and rear brakes are identical,
only one brake needs to be tested. If rims are identical (spoke count, material, design), only one wheel
needs to be tested.
4.6.9.2 Requirement for disc brakes, hub brakes and rim brakes and pads (alloy or steel rim, composite
rims are excluded from this section)
Throughout the test described in EN ISO 4210-4:2014, 4.7, the brake lever shall not touch the handlebar
grip, the operating force shall not exceed 180 N, and the braking force shall not deviate outside the
range 60 N to 115 N.
Immediately after having been subjected to the test described in EN ISO 4210-4:2014, 4.7, the brakes
shall achieve at least 60 % of the braking performance which was recorded at the highest operating
force used during the performance tests EN ISO 4210-4:2014, 4.6.5.7 c) items 1) and 2).
4.6.9.3 Requirement for rim brakes and pads used with composite rims - Addition
A new wheel with new brake pads (recommended by the wheel/rim manufacturer) and a new tyre
(tubular tyre, tyre w/inner tube or tubeless tyre) shall be subjected to two consecutive
...