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GB 20073-2018: Performance and measurement method for braking of motorcycles and mopeds
GB 20073-2018
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.140
T 80
Replacing GB 20073-2006
Performance and Measurement Method for Braking of
Motorcycles and Mopeds
ISSUED ON: FEBRUARY 06, 2018
IMPLEMENTED ON: JULY 01, 2018
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 5
4 Requirements ... 8
5 Test ... 11
6 Implementation of this Standard ... 13
Appendix A (Normative) Braking Test and Performance Requirements ... 15
Appendix B (Normative) Test and Performance Requirements of Antilock Brake
System ... 29
Appendix C (Normative) Partial Failure Test and Performance Requirements for Split
Service Brake System ... 35
Appendix D (Normative) Failure Test and Performance Requirements for Power-
Assisted Braking System ... 37
Appendix E (Normative) Failure Test and Performance Requirements of Combined
Brake System ... 38
Appendix F (Normative) Determination of Peak Braking Coefficient ... 40
Performance and Measurement Method for Braking of
Motorcycles and Mopeds
1 Scope
This Standard specifies the braking performance requirements and test methods for motorcycles
and mopeds.
This Standard applies to motorcycles and mopeds.
This Standard does not apply to the carriages for disabled persons.
2 Normative References
The following documents are essential to the application of this document. For the dated
documents, only the versions with the dates indicated are applicable to this document; for the
undated documents, only the latest version (including all the amendments) is applicable to this
document.
GB/T 5359.4 Term for Motorcycles and Mopeds - Part 4: Mass of Vehicle with Two and
Three Wheels
GB/T 5378 Methods of Road Test for Motorcycles and Mopeds
GB/T 15089-2001 Classification of Power-Driven Vehicles and Trailers
ASTM E867 Terminology Relating to Vehicle-Pavement Systems
ASTM E1136 Specification for A Radial Standard Reference Test Tire
ASTM F408 Test Method for Tires for Wet Traction in Straight-Ahead Braking, using a
Towed Trailer
ASTM F457 Test Method for Speed and Distance Calibration of Fifth Wheel Equipped
with Either Analog or Digital Instrumentation
3 Terms and Definitions
For the purposes of this Document, the Category-L vehicle defined in GB/T 15089-2001 and
the following terms and definitions apply.
3.1 Brake system
A component combination that gradually slows down or stops a moving vehicle, or keeps a
stopped vehicle stationary. The device consists of a control, a transmission and a brake, but
does not include an engine.
3.2 Control
A component that is directly operated by the driver to provide the transmission with the energy
required for braking or controlling.
3.3 Transmission
The combination of components between the control and the brake that connects their functions.
3.4 Brake
A component in a brake system that produces forces to prevent vehicle movement.
3.5 Service brake system
A brake system that slows down a moving vehicle.
3.6 Secondary brake system
The second set of service brake systems that are installed on vehicles equipped with a combined
brake system.
3.7 Single brake system
A brake system that only acts on one axle.
3.8 Combined brake system; CBS
a) For two-wheeled mopeds (Category-L1) and two-wheeled motorcycles (Category-L3), a
set of service brake system that operates a single control can jointly control at least two
brakes on different wheels;
b) For three-wheeled mopeds (Category-L2) and right three-wheeled motorcycles
(Category-L5), a set of service brake system that operates a single control can jointly
control the brakes on all wheels;
c) For motorcycle with sidecar (Category-L4), a set of service brake system that operates a
single control can control at least brakes on the front and rear wheels. A brake system
that controls both the rear and side wheels shall be considered a rear brake.
3.9 Split service brake system; SSBS
A brake system that controls the brakes on all wheels, where a single control controls two or
more subsystems. The failure of any one subsystem (such as system failure caused by hydraulic
pipeline leakage) cannot affect the function of other subsystems.
3.10 Power-assisted braking system
A brake system in which the driver's physical force is assisted by one or more energy supply
devices to apply the braking force. Such as vacuum booster brake system (with vacuum booster).
3.11 Antilock brake system; ABS
A system that can determine the degree of wheel slip relative to the ground, and can
automatically adjust the braking force of the wheel, thereby limiting the degree of wheel slip
relative to the ground.
3.12 Wheel lock
The case when the wheel slip is 1.00.
3.13 Peak braking coefficient; PBC
The coefficient of friction between the tire and the road surface that is measured based on the
maximum deceleration of the rolling tire.
3.14 Vmax
The maximum speed that is measured according to the test method specified in GB/T 5378.
3.15 Engine disconnected
The engine is disconnected from the drive wheels.
3.16 Initial brake system
The temperature of the brakes before any braking is applied. If multiple brakes are controlled
at the same time, select the temperature of the brake with the highest temperature.
3.17 Laden
Load the vehicle to its factory-set maximum gross mass (as per GB/T 5359.4).
3.18 Lightly loaded
It is whichever is the lesser BETWEEN the sum of vehicle curb weight (as per GB/T 5359.4)
plus the driver's mass (75kg) plus the test equipment mass (15kg) AND the laden mass.
When the antilock brake system test is carried out on the road with low friction coefficient, the
mass of the test equipment (including the protective bracket) is 30kg.
4.2.3.2 The parking brake system shall:
a) Contains a control and is separate from the control of the service brake system;
b) Only use purely mechanical means to lock the working parts.
4.2.3.3 It shall be ensured that the driver can operate the parking brake system from the normal
driving position.
4.2.3.4 The parking brake systems installed on three-wheeled mopeds (Category-L2),
motorcycles with sidecars (Category-L4) and right three-wheeled motorcycles (Category-L5)
shall be tested in accordance with A.3.5 in Appendix A and meet the requirements of
performance requirements.
4.3 Characteristics of the brake system
4.3.1 Two-wheeled mopeds (Category-L1) and two-wheeled motorcycles (Category-L3) shall
be equipped with two sets of independent service brake systems, or a set of split service brake
system, in which at least one brake controls the front wheel, another brake controls the rear
wheel.
4.3.2 Special requirements for two-wheeled motorcycles (Category-L3):
a) Two-wheeled motorcycles (Category-L3) with an actual engine displacement greater than
150mL and less than or equal to 250mL shall be equipped with an antilock brake system
or a combined brake system;
b) For two-wheeled motorcycles (Category-L3) with actual engine displacement greater than
250mL, antilock brake system shall be installed on both front and rear wheels.
4.3.3 Motorcycles with sidecars (Category-L4) shall comply with the provisions of 4.3.1. If the
performance requirements specified in each test can be met...