ASTM F2711-19

Standard Test Methods for Bicycle Frames

SIGNIFICANCE AND USE
5.1 These tests are used to verify the durability and strength of a bicycle frame.
SCOPE
1.1 These test methods establish procedures for conducting tests to determine the structural performance properties of bicycle frames.  
1.2 These test methods describe mechanical tests for determining the following performance properties:  
1.2.1 Frame Fatigue – Horizontal Loading  
1.2.2 Frame Fatigue – Vertical Loading  
1.2.3 Falling Mass – Horizontal Loading  
1.2.4 Falling Frame – Vertical Loading  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2019
• ICS: 43.150 - Cycles
• Technical Committee: F08 - Sports Equipment, Playing Surfaces, and Facilities
• Drafting Committee: F08.10 - Bicycles

Relations

• Replaces: ASTM F2711-08(2012) - Standard Test Methods for Bicycle Frames
• Effective Date: 01-Oct-2019
• Refers: ASTM E4-14 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Jun-2014
• Refers: ASTM E4-10 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Jun-2010
• Refers: ASTM E4-09a - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Nov-2009
• Refers: ASTM E4-09 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Apr-2009
• Refers: ASTM E4-08 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Dec-2008
• Refers: ASTM E4-07 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Jan-2007
• Refers: ASTM E4-03 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 10-Aug-2003
• Refers: ASTM E4-02 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 10-Nov-2002
• Refers: ASTM E4-01 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 10-Apr-2001
• Refers: ASTM E4-99 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 10-Apr-2001
• Referred By: ASTM F2843-19 - Standard Specification for Condition 0 Bicycle Frames
• Effective Date: 01-Oct-2019
• Referred By: ASTM F2868-19 - Standard Specification for Condition 2 Bicycle Frames
• Effective Date: 01-Oct-2019
• Referred By: ASTM F2614-19 - Standard Specification for Condition 3 Bicycle Frames
• Effective Date: 01-Oct-2019
• Referred By: ASTM F2802-19 - Standard Specification for Condition 1 Bicycle Frames
• Effective Date: 01-Oct-2019

Overview

ASTM F2711-19: Standard Test Methods for Bicycle Frames specifies mechanical testing procedures to determine the structural performance of bicycle frames. Developed by ASTM International, this standard focuses on assessing the durability and strength of bicycle frames under different load conditions. The procedures outlined in ASTM F2711-19 help manufacturers, laboratories, and regulatory authorities verify that bicycle frames meet key safety and quality requirements.

Key Topics

• Structural Performance: The standard outlines procedures to evaluate frame strength and durability, ensuring frames can withstand real-world stresses.
• Fatigue Testing: Includes both horizontal and vertical load fatigue tests to simulate repetitive loading conditions experienced during cycling.
  • Horizontal Loading Fatigue Test
  • Vertical Loading Fatigue Test
• Impact Strength Testing: Details falling mass and falling frame tests to assess the frame's ability to absorb and withstand sudden impacts.
  • Falling Mass – Horizontal Loading Test
  • Falling Frame – Vertical Loading Test
• Test Apparatus and Calibration: Specifies requirements for test forks, test fixtures, and calibration procedures to ensure accurate and repeatable results.
• Sample Handling: Provides guidance on the use of frame samples, test sequences, and criteria for passing or failing test results.

Applications

The ASTM F2711-19 standard is widely used in the bicycle industry for:

• Product Development: Designers and engineers use these test methods to validate new bicycle frame designs for safety and durability before mass production.
• Quality Assurance: Manufacturers apply these tests during production to maintain a consistent standard of strength and resilience in their bicycle frames.
• Third-Party Testing: Independent laboratories utilize these methods to certify product compliance with international standards and regulatory requirements.
• Regulatory Compliance: Meeting ASTM F2711-19 requirements ensures alignment with internationally recognized safety principles and addresses technical barriers to trade.
• Aftermarket and OEM Verification: Both original equipment manufacturers and aftermarket suppliers use the standard to verify the performance of bicycle frames against industry benchmarks.

Practical Benefits

• Enhances product safety and durability
• Provides a repeatable methodology for frame assessment
• Supports market access by aligning with global standards
• Assists in identifying design or production flaws early

Related Standards

For comprehensive bicycle safety and quality evaluation, ASTM F2711-19 may be used in conjunction with:

• ASTM E4: Practices for Force Verification of Testing Machines
• ISO Bicycle Safety Standards: For global compliance and interoperability
• National and Regional Bicycle Regulations: For market-specific requirements

Keywords: ASTM F2711-19, bicycle frame testing, structural performance, fatigue testing, impact strength, quality assurance, bicycle safety, frame durability, international standards, testing procedures

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Meeting the requirements of ASTM F2711-19 ensures that bicycle frames are robust, reliable, and safe for consumer use, supporting manufacturers’ confidence in product quality and consumer trust in bicycle safety.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2711 − 19 An American National Standard
Standard Test Methods for
Bicycle Frames
This standard is issued under the fixed designation F2711; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1.1 Discussion—Theforktransmitssteeringtorquefrom
the handlebars to the front wheel.
1.1 These test methods establish procedures for conducting
tests to determine the structural performance properties of 3.1.2 bicycle frame, n—structural member that supports the
bicycle frames. seat with rear connection for the rear wheel, front connection
via the head tube for the fork and lower connection for the
1.2 These test methods describe mechanical tests for deter-
crank/pedal assembly.
mining the following performance properties:
1.2.1 Frame Fatigue – Horizontal Loading 3.1.3 bottom bracket shell, n—structural member of the
1.2.2 Frame Fatigue – Vertical Loading frame that houses the assembly that supports the bearings,
1.2.3 Falling Mass – Horizontal Loading which support the cranks.
1.2.4 Falling Frame – Vertical Loading
3.1.4 crank, n—lever arm that receives human energy as
1.3 The values stated in SI units are to be regarded as torque to convert into bicycle motion.
standard. No other units of measurement are included in this
3.1.5 crown race seat, n—position on the fork where the
standard.
lower steering axis bearing sits.
1.4 This standard does not purport to address all of the
3.1.6 down tube, n—lower structural connection between
safety concerns, if any, associated with its use. It is the
the head tube and the bottom bracket shell.
responsibility of the user of this standard to establish appro-
3.1.7 dropout centerline, n—hub-mounting axis that passes
priate safety, health, and environmental practices and deter-
through both right and left dropouts.
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
3.1.8 front dropout, n—area where the front wheel hub
dance with internationally recognized principles on standard-
connects to the fork.
ization established in the Decision on Principles for the
3.1.9 head tube, n—forward most structural member of the
Development of International Standards, Guides and Recom-
frame, which provides an interface through top, and bottom
mendations issued by the World Trade Organization Technical
bearings for the fork.
Barriers to Trade (TBT) Committee.
3.1.9.1 Discussion—The head tube is connected to the seat
tube through the top tube and the down tube.
2. Referenced Documents
3.1.10 initial running displacement, n—average displace-
2.1 ASTM Standards:
ment between approximately 500 and 1000 cycles during a
E4 Practices for Force Verification of Testing Machines
durability fatigue test.
3. Terminology
3.1.11 normal attitude, n—intended position of the bicycle
3.1 Definitions of Terms Specific to This Standard: framewhenincontinuousstraight-linemotiononaflatsurface.
3.1.1 bicycle fork, n—structural connection between the
3.1.12 rake, n—straight-line distance from the front axle
front wheel and the frame.
center to the perpendicular of the steering axis.
3.1.13 rear dropout, n—area where the rear wheel hub
These test methods are under the jurisdiction of ASTM Committee F08 on connects to the lower rear and the upper rear frame members.
Sports Equipment, Playing Surfaces, and Facilities and are the direct responsibility
3.1.14 sag, n—amount of compression in a suspension unit,
of Subcommittee F08.10 on Bicycles.
Current edition approved Oct. 1, 2019. Published November 2019. Originally given in a percentage.
approved in 2008. Last previous edition approved in 2012 as F2711 - 08 (2012).
3.1.15 seat post, n—structural component that connects the
DOI: 10.1520/F2711-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or seat to the seat tube.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3.1.16 seat tube, n—structural member of the frame into
Standardsvolume information, refer to the standard’s Document Summary page on
the ASTM website. which the seat post inserts.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2711 − 19
3.1.17 steerer tube, n—section of the bicycle fork that is 6.1.1 The test forks shall be designed to mount in a manner
housed within the head tube and bearing assemblies. similar to the OEM fork, or in a manner using typical bicycle
assembly procedures.
3.1.18 top tube, n—upper structural connection between the
6.1.2 The test forks, when mounted, shall be the same
head tube and the seat tube.
length, L, as the longest fork designed for use with the frame
3.2 Acronyms:
and have a rake of 45 6 6 mm. When the test fork is used in
3.2.1 OEM, n—original equipment from manufacturer
place of an OEM Suspension fork, the length is determined by
3.3 Symbols:
the dropout position when the suspension fork is compressed
L = fork length, a straight-line measure from the crown race
no more than 20 % of its maximum amount of travel.
seat to the center of the front axle.
6.1.3 The deflection of a test fork is measured at the front
δ = deflection of test fork.
axle center, resulting from the application of a vertical 1200 N
load at that point. The fork is fixed in position only at the
4. Summary of Test Methods
steerer tube by a v-block with minimum length of 76 mm. The
4.1 Horizontal Loading Durability Fatigue Test—This test
steerer tube is fixed horizontally with the crown race seat
method restrains the frame at the rear dropouts (see Fig. 1). A
adjacent to the v-block.
cyclicloadisappliedalongthex-axisatthefrontdropouts.The
6.1.4 ThedeflectionratiofortheTestforkfortheHorizontal
number of cycles is measured. The magnitude of the load, and
LoadingFatiguetestandtheVerticalLoadingFatiguetestshall
the minimum number of cycles, are determined by the speci-
not exceed the value of 1.0 when computed as follows:
fication standard.
K 310 000 3δ
Deflection ratio 5
4.2 Vertical Loading Durability Fatigue Test—This test
L
methodrestrainstheframeatthereardropouts,andallowsfree
Where:
rollingatthefork(seeFig.2).Acyclicloadisappliedalongthe
K (a constant) = 1417 for L and δ in millimetres.
Z-axis behind the seat post.The number of cycles is measured.
Themagnitudeoftheload,andtheminimumnumberofcycles,
(For example, a fork length of 460 mm, the maximum
are determined by the specification standard.
acceptable fork deflection (δ) would be 6.9 mm. Similarly for
a fork length of 330 mm, the maximum deflection is 2.5 mm.)
4.3 Falling Mass Test—This test method restrains the frame
6.1.5 The deflection ratio for the Test fork for the Impact
vertically at the rear dropouts (see Fig. 3). A mass is dropped
onto a roller assembly attached to the fork. Permanent set is test shall not exceed the value of 1.0 when computed as
follows:
measured. The height of the drop is determined by the
specification standard.
K 310 000 3δ
Deflection ratio 5
L
4.4 Falling Frame Test—This test method pins the frame at
the rear dropouts (see Fig. 4), weight is loaded on the frame,
Where:
the frame rotates to drop onto a roller in the front dropouts.
K = 709 for L and δ in millimetres.
5. Significance and Use
6.2 Horizontal Loading Durability Fatigue Test:
5.1 These tests are used to verify the durability and strength 6.2.1 A fixture is required to restrain the frame at the rear
of a bicycle frame.
dropouts, while allowing free rotation about the axle (see Fig.
1). In the case of a suspension frame, the suspension must be
6. Apparatus
locked in a position equivalent to the manufacturer’s recom-
6.1 Requirements for Test Forks: mendation for sag for an 80 kg rider, or 25 % sag if none was
FIG. 1 Horizontal Fatigue Test
F2711 − 19
FIG. 2 Vertical Fatigue Test
recommended. If the suspension does not permit locking, then 5); and free rotation of the fork assembly about the front axle;
replace the suspension unit with a solid link providing the while movement in the Y-axis and Z-axis is constrained.
equivalent sag geometry. 6.3.5 The front and rear dropouts are to be equal height
6.2.2 A test fork meeting the requirements for this test (see when the frame and fork assembly is fixtured.
6.1) shall be used. 6.3.6 A round solid steel loading bar equivalent to a seat
6.2.3 The fork shall be attached to the bicycle frame head post shall be inserted into the top of the seat tube, and secured
tube using typical bicycle assembly practices. to the seat tube by the manufacturers instructions using the
6.2.4 The fork assembly shall be restrained at the dropouts normal clamp. A horizontal rearward extension shall be se-
in such a way that allows translation along the X-axis, and curely attached to the top of this bar such that its height, h, is
rotation about the Y-axis. equal to the maximum saddle height for that particular frame,
6.2.5 The front and rear dropouts are to be equal in height as shown in Fig. 2.The extension bar shall permit loading with
when the frame and fork assembly is fixtured. a 70 mm rearward offset.
6.2.6 An actuator mounted load cell or equivalent apparatus 6.3.7 An actuator mounted load cell or equivalent apparatus
that is capable of providing a reversible load of constant that is capable of providing a reversible load, is attached to the
amplitude shall be attached to the front dropouts or front axle, rearward extension and aligned in the vertical, downward,
without constricting the rotational freedom of the fork assem- direction.
bly.
6.4 Falling Mass Test:
6.2.7 This apparatus shall allow cyclic load application to
6.4.1 A fixture is required to restrain the frame at the rear
the front dropouts in a longitudinal direction along the bicycle
dropouts, while holding the frame securely in a vertical
centerline.
orientation (Fig. 3). In the case of a suspension frame, the
6.3 Vertical Loading Durability Fatigue Test: suspension must be locked in a position equivalent to the
6.3.1 A fixture is required to restrain the frame at the rear manufacturer’s recommendation for sag for an 80 kg rider, or
dropouts, while allowing free rotation about the rear axle (Fig. 25%sagifnonewasrecommended.Ifthesuspensiondoesnot
2). In the case of a suspension frame, the suspension must be permit locking, then replace the suspension unit with a solid
locked in a position equivalent to the manufacturer’
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2711 − 08 (Reapproved 2012) F2711 − 19 An American National Standard
Standard Test Methods for
Bicycle Frames
This standard is issued under the fixed designation F2711; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 These test methods establish procedures for conducting tests to determine the structural performance properties of bicycle
frames.
1.2 These test methods describe mechanical tests for determining the following performance properties:
1.2.1 Frame Fatigue—Horizontal Loading,Fatigue – Horizontal Loading
1.2.2 Frame Fatigue—Vertical Loading, andFatigue – Vertical Loading
1.2.3 Falling Mass – Horizontal Loading
1.2.4 Frame Impact Strength.Falling Frame – Vertical Loading
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 bicycle, n—two-wheeled, single track, articulated vehicle that is solely human powered.
3.1.1 bicycle fork, n—structural connection between the front wheel and the frame.
3.1.1.1 Discussion—
The fork transmits steering torque from the handlebars to the front wheel.
3.1.2 bicycle frame, n—structural member that supports the seat with rear connection for the rear wheel, front connection via
the head tube for the fork and lower connection for the crank/pedal assembly.
3.1.3 bottom bracket shell, n—structural member of the frame that houses the assembly that supports the bearings, which
support the cranks.
3.1.4 crank, n—lever arm that receives human energy as torque to convert into bicycle motion.
3.1.5 crown race seat, n—position on the fork where the lower steering axis bearing sits.
3.1.6 down tube, n—lower structural connection between the head tube and the bottom bracket shell.
ThisThese test method ismethods are under the jurisdiction of ASTM Committee F08 on Sports Equipment, Playing Surfaces, and Facilities and isare the direct
responsibility of Subcommittee F08.10 on Bicycles.
Current edition approved Nov. 1, 2012Oct. 1, 2019. Published December 2012November 2019. Originally approved in 2008. Last previous edition approved in 20082012
as F2711 – 08. DOI: 10.1520/F2711-08.- 08 (2012). DOI: 10.1520/F2711-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standardsvolume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2711 − 19
3.1.7 dropout centerline, n—hub-mounting axis that passes through both right and left dropouts.
3.1.8 front dropout, n—area where the front wheel hub connects to the fork.
3.1.9 head tube, n—forward most structural member of the frame, which provides an interface through top, and bottom bearings
for the fork.
3.1.9.1 Discussion—
The head tube is connected to the seat tube through the top tube and the down tube.
3.1.10 initial running displacement, n—average displacement between approximately 500 and 1000 cycles during a durability
fatigue test.
3.1.11 normal attitude, n—intended position of the bicycle frame when in continuous straight-line motion on a flat surface.
3.1.12 rake, n—straight-line distance from the front axle center to the perpendicular of the steering axis.
3.1.13 rear dropout, n—area where the rear wheel hub connects to the lower rear and the upper rear frame members.
3.1.14 sag, n—amount of compression in a suspension unit, given in a percentage.
3.1.15 seat post, n—structural component that connects the seat to the seat tube.
3.1.16 seat tube, n—structural member of the frame into which the seat post inserts.
3.1.17 steerer tube, n—section of the bicycle fork that is housed within the head tube and bearing assemblies.
3.1.18 top tube, n—upper structural connection between the head tube and the seat tube.
3.2 Acronyms:
3.2.1 OEM, n—original equipment from manufacturer
3.3 Symbols:
L = fork length, a straight-line measure from the crown race seat to the center of the front axle.
δ = deflection of test fork.
4. Summary of Test Methods
4.1 Horizontal Loading Durability Fatigue Test—This test method restrains the frame at the rear dropouts (see Fig. 1). A cyclic
load is applied along the x-axis at the front dropouts. The number of cycles is measured. The magnitude of the load, and the
minimum number of cycles, are determined by the specification standard.
4.2 Vertical Loading Durability Fatigue Test—This test method restrains the frame at the rear dropouts, and allows free rolling
at the fork (see Fig. 2). A cyclic load is applied along the Z-axis behind the seat post. The number of cycles is measured. The
magnitude of the load, and the minimum number of cycles, are determined by the specification standard.
4.3 Impact StrengthFalling Mass Test—This test method restrains the frame vertically at the rear dropouts (see Fig. 3). A mass
is dropped onto a roller assembly attached to the fork. Permanent set is measured. The height of the drop is determined by the
specification standard.
4.4 Falling Frame Test—This test method pins the frame at the rear dropouts (see Fig. 4), weight is loaded on the frame, the
frame rotates to drop onto a roller in the front dropouts.
FIG. 1 Horizontal Fatigue Test
F2711 − 19
FIG. 2 Vertical Fatigue Test
5. Significance and Use
5.1 These tests are used to verify the durability and strength of a bicycle frame.
6. Apparatus
6.1 Requirements for Test Forks:
6.1.1 The test forks shall be designed to mount in a manner similar to the OEM fork, or in a manner using typical bicycle
assembly procedures.
6.1.2 The test forks, when mounted, shall be the same length, L, as the longest fork designed for use with the frame and have
a rake of 45 6 6 mm. When the test fork is used in place of an OEM Suspension fork, the length is determined by the dropout
position when the suspension fork is compressed no more than 20 % of its maximum amount of travel.
6.1.3 The deflection of a test fork is measured at the front axle center, resulting from the application of a vertical 1200 N load
at that point. The fork is fixed in position only at the steerer tube by a v-block with minimum length of 76 mm. The steerer tube
is fixed horizontally with the crown race seat adjacent to the v-block.
6.1.4 The deflection ratio for the Test fork for the Horizontal Loading Fatigue test and the Vertical Loading Fatigue test shall
not exceed the value of 1.0 when computed as follows:
K 310 000 3δ
Deflection ratio 5
L
Where:
K (a constant) = 1417 for L and δ in millimetres.
(For example, a fork length of 460 mm, the maximum acceptable fork deflection (δ) would be 6.9 mm. Similarly for a fork length
of 330 mm, the maximum deflection is 2.5 mm.)
6.1.5 The deflection ratio for the Test fork for the Impact test shall not exceed the value of 1.0 when computed as follows:
K 310 000 3δ
Deflection ratio 5
L
Where:
K = 709 for L and δ in millimetres.
6.2 Horizontal Loading Durability Fatigue Test:
6.2.1 A fixture is required to restrain the frame at the rear dropouts, while allowing free rotation about the axle (see Fig. 1). In
the case of a suspension frame, the suspension must be locked in a position equivalent to the manufacturer’s recommendation for
sag, sag for an 80 kg rider, or 25 % sag if none was recommended. If the suspension does not permit locking, then replace the
suspension unit with a solid link providing the equivalent sag geometry.
6.2.2 A test fork meeting the requirements for this test (see 6.1) shall be used.
6.2.3 The fork shall be attached to the bicycle frame head tube using typical bicycle assembly practices.
F2711 − 19
FIG. 3 Frame ImpactFalling Mass Test
6.2.4 The fork assembly shall be restrained at the dropouts in such a way that allows translation along the X-axis, and rotation
about the Y-axis.
6.2.5 The front and rear dropouts are to be equal in height when the frame and fork assembly is fixtured.
6.2.6 An actuator mounted load cell or equivalent apparatus that is capable of providing a reversible load of constant amplitude
shall be attached to the front dropouts or front axle, without constricting the rotational freedom of the fork assembly.
6.2.7 This apparatus shall allow cyclic load application to the front dropouts in a longitudinal direction along the bicycle
centerline.
6.3 Vertical Loading Durability Fatigue Test:
6.3.1 A fixture is required to restrain the frame at the rear dropouts, while allowing free rotation about the rear axle (Fig. 2).
In the case of a suspension frame, the suspension must be locked in a position equivalent to the manufacturer’s recommendation
for sag, sag for an 80 kg rider, or 25 % sag if none was recommended. If the suspension does not permit locking, then replace the
suspension unit with a solid link providing the equivalent sag geometry.
6.3.2 A test fork meeting the requirements for this test (see 6.1) shall be used.
6.3.3 The fork shall be attached to the bicycle frame head tube using typical bicycle assembly practices.
6.3.4 The fork assembly shall be restrained at the dropouts in such a way that allows translation along the X-axis (see Fig. 45);
and free rotation of the fork assembly about the front axle; while movement in the Y-axis and Z-axis is constrained.
6.3.5 The front and rear dropouts are to be equal height when the frame and fork assembly is fixtured.
F2711 − 19
FIG. 4 Falling Frame Test
FIG. 45 Frame Coordinate System
6.3.6 A round solid steel loading bar equivalent to a seat post shall be inserted into the top of the seat tube, and secured to the
seat tube by the manufacturers instructions using the normal clamp. A horizontal rearward extension shall be securely attached to
the top of this bar such that its height, h, is equal to the maximum saddle height for that particular frame, as shown in Fig. 2. The
extension bar shall permit loading with a 70 mm rearward offset.
6.3.7 An actuator mounted load cell or equivalent apparatus that is capable of providing a reversible load, is attached to the
rearward extension and aligned in the vertical, downward, d
...