Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
Chapters 1, 4 and 5, and annexes A to F of this standard are mandatory.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB 20073-2006 Performance and measurement method for braking of motorcycles and mopeds.
The following main changes have been made with respect to GB 20073-2006:
——the scope is modified where the "vehicles with the maximum design speed less than 25 km/h" is deleted (see Chapter 1 hereof, Chapter 1 of 2006 edition);
——the normative references are modified (see Chapter 2 hereof, Chapter 2 of 2006 edition);
——the terms and definitions of service brake system, secondary brake system, single brake system, split service brake system, power-assisted braking system, antilock brake system, wheel lock, peak braking coefficient, Vmax, engine disconnected, initial brake temperature, lightly loaded, test speed, stopping distance, baseline test and fully cycling are added (see Chapter 3 hereof);
——the terms and definitions of component(s) of a braking device, unladen vehicle and wet brake are deleted (see 3.5, 3.8 and 3.9 of 2006 edition);
——the requirements for functions and characteristics of brake system are modified (see 4.2 and 4.3 hereof, 4.1.2 and 4.2 of 2006 edition);
——the requirements for brake master cylinder, warning light and friction lining, and the performance requirements for brake system are added (see 4.4 to 4.7 hereof);
——the requirements for test road, environmental conditions, test speed, automatic gearbox, vehicle position, wheel lock and test sequence, and the test methods are modified (see Chapter 5 hereof, A.1.2 and A.1.3 of 2006 edition);
——the methods and performance requirements for running-in test, dry brake test of separately operated brake control, dry brake test of simultaneously operated brake control, high-speed brake test, failure test of split service brake system, failure test of power-assisted braking system, and failure test of combined brake system are added (see Annexes A to E hereof);
——the method and performance requirements for type 0 test of engine disconnected, two-wheeled motorcycles and engine connected are deleted (see A.1.4.2 and A.1.4.3 of 2006 edition);
——the methods for wet brake test and fade test are modified (see A.3.4 and A.3.6 hereof, A.1.4.4 and A.1.6 of 2006 edition);
——the applicable scope, method and performance requirements for parking brake system test are modified (see A.3.5 hereof, A.2.3 of 2006 edition);
——the method and performance requirements for antilock brake system test are modified (see Annex B hereof, Annex B and Annex C of 2006 edition);
——the method for measurement of peak braking coefficient on the test surface is added and written as a normative annex of this standard (see Annex F hereof).
This standard was proposed by and is under the jurisdiction of the Ministry of Industry and Information Technology of the People's Republic of China.
The previous editions of the standard replaced by this standard are as follows:
——GB 5382-1985;
——GB/T 5382.1-1996;
——GB 17355-1998;
——GB 20073-2006.
Performance and measurement method for braking of motorcycles and mopeds
1 Scope
This standard specifies requirements and test method for brake performance of motorcycles and mopeds.
This standard is applicable to motorcycles and mopeds.
This standard is not applicable to vehicles for the disabled.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
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 terms and definitions given in GB/T 15089-2001 for Category L vehicles and the followings apply.
3.1
brake system
a combination of components consisting of control, transmission, and brake, but excluding engine, whose function is to progressively reduce the speed of a moving vehicle, bring it to a halt, and keep it stationary when halted
3.2
control
a part actuated directly by the rider in order to supply or control the energy required for braking the vehicle to the transmission
3.3
transmission
a combination of components that provide the functional link between the control and the brake
3.4
brake
parts of the brake system where the forces opposing the movement of the vehicle are developed
3.5
service brake system
a brake system which slows down the vehicle when in motion
3.6
secondary brake system
second service brake system on a vehicle equipped with a combined brake system
3.7
single brake system
a brake system which acts on only one axle
3.8
combined brake system, CBS
a) for two-wheeled mopeds (Category L1) and motorcycles (Category L3), a service brake system where at least two brakes on different wheels are operated by the actuation of a single control
b) for three-wheeled mopeds (Category L2) and right three-wheeled motorcycles (Category L5), a service brake system where the brakes on all wheels are operated by the actuation of a single control
c) for motorcycles with sidecar (Category L4), a service brake system where the brakes on at least the front and rear wheels are operated by the actuation of a single control. If the rear wheel and sidecar wheel are braked by the same brake system, this is regarded as the rear brake.
3.9
split service brake system, SSBS
a brake system that operate the brakes on all wheels, consisting of two or more subsystems actuated by a single control designed so that a single failure in any subsystem (such as a leakage type failure of a hydraulic pipeline) does not impair the operation of any other subsystem
3.10
power-assisted braking system
a brake system in which the energy necessary to produce the braking force is supplied by the physical effort of the rider assisted by one or more energy supplying devices, for example vacuum assisted braking system (with vacuum booster)
3.11
antilock brake system, ABS
a system which senses wheel slip and automatically modulates the pressure producing the braking forces at the wheel(s) to limit the degree of wheel slip
3.12
wheel lock
a condition that occurs when there is a slip ratio of 1.00
3.13
peak braking coefficient, PBC
measure of tyre to road surface friction based on the maximum deceleration of a rolling tyre
3.14
Vmax
maximum speed measured in accordance with the method given in GB/T 5378
3.15
engine disconnected
disconnection of the engine from the driving wheel(s)
3.16
initial brake temperature
temperature of the brake before any brake application. If more than one brakes are operated simultaneously, the temperature of the hottest brake shall be selected.
3.17
laden
so loaded as to attain the maximum mass as defined by the manufacturer (in accordance with GB/T 5359.4)
3.18
lightly loaded
sum of the complete vehicle kerb mass (in accordance with GB/T 5359.4), rider mass (75 kg) and the mass of test equipment (15 kg), or the laden mass, whichever is less
In the case of ABS tests on a low friction surface, the mass of test equipment (including protective supports) is 30 kg.
3.19
test speed
vehicle speed measured at the moment the rider begins to actuate the brake control(s). For tests where the simultaneous actuation of two controls is specified, the vehicle speed is taken from the point the first control is actuated.
3.20
stopping distance
distance traveled by the vehicle from the point the rider begins to actuate the brake control to the point at which the vehicle reaches a full stop. For tests where the simultaneous actuation of two controls is specified, the vehicle speed is taken from the point the first control is actuated.
3.21
baseline test
a brake test or a series of brake tests carried out in order to confirm the performance of the brake prior to subjecting it to a further test such as the heat fade test or wet brake test
3.22
fully cycling
a process where the ABS repeatedly or continuously modulates the braking force in order to prevent directly actuated wheel lock
4 Requirements
4.1 General
The vehicle shall comply with the test requirements specified by its type and brake system characteristics.
4.2 Functions of brake system
4.2.1 Service brake system
The rider shall be able to actuate the service brake system control on the normal riding position without removing his hands from the handlebar (or steering control).
4.2.2 Secondary brake system (if any)
The rider shall be able to actuate the secondary brake system control on the normal riding position with at least one hand holding the handlebar (or steering control).
4.2.3 Parking brake system (if any)
4.2.3.1 The parking brake system fitted to the vehicle, if any, shall stabilize the vehicle on the test ramp as described in 5.1.1.3.
4.2.3.2 The parking brake system shall
a) comprise a control which is isolated from the service brake system control;
b) lock the working parts only in a purely mechanical manner.
4.2.3.3 The rider shall be able to actuate the parking brake system on the normal riding position.
4.2.3.4 The parking brake system fitted to three-wheeled mopeds (Category L2), motorcycles with sidecar (Category L4) and right three-wheeled motorcycles (Category L5) shall be tested according to Annex A, A.3.5, and shall meet the performance requirements.
4.3 Characteristics of brake system
4.3.1 Two-wheeled mopeds (Category L1) and motorcycles (Category L3) shall be fitted with two independent service brake systems or a split service brake system, with at least one brake controlling the front wheel and the other controlling 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 150 mL and less than or equal to 250 mL shall be fitted with antilock brake system or combined brake system;
b) Two-wheeled motorcycles (Category L3) with an actual engine displacement greater than 250 mL shall be fitted with antilock brake system on the front and rear wheels.
4.3.3 Motorcycles with sidecar (Category L4) shall comply with the requirements of 4.3.1. If the performance requirements specified in each test are met, brake is not required for the sidecar.
4.3.4 Three-wheeled mopeds (Category L2) shall be fitted with a parking brake system and one of the following brake systems:
——two independent service brake systems (except for combined brake system), which can control the brakes on all wheels concurrently;
——a split service brake system; or
——a combined brake system that can control the brakes on all wheels, and a secondary brake system or parking brake system.
4.3.5 Right three-wheeled motorcycles (Category L5) shall be fitted with a parking brake system and a foot-operated service brake system for controlling the brakes on all wheels which may be
——a split service brake system; or
——a combined brake system and a secondary brake system which may be a parking brake system.
4.3.6 If the requirements of failure test for combined brake system are met, two independent service brake systems can share the same brake and transmission.
4.4 Brake master cylinder
For vehicles using hydraulic transmission, the brake master cylinder shall comply with the following requirements:
——each brake system shall have an independent sealed and covered reservoir;
——the minimum capacity of the reservoir shall be 1.5 times the liquid volume required for the brake’s friction lining to be adjusted from a brand new state to a completely worn state;
——the liquid level should be inspected without opening the reservoir.
4.5 Warning light
4.5.1 Warning light of the brake system shall be so arranged as to be convenient for the rider to observe and identify on the normal operating position.
4.5.2 Vehicles equipped with an antilock brake system shall be fitted with a yellow warning light:
a) the warning light shall work when the vehicle’s ignition switch is turned on, and go out after the function test is finished;
b) the warning light shall display when the antilock brake system fails and affects the generation and transmission of system signals. The warning light shall remain displayed provided the fault is still present and the ignition switch is in the “ON” position.
4.5.3 Vehicles equipped with a split service brake system shall be fitted with a red warning light:
a) the warning light shall work when the vehicle’s ignition switch is turned on, and go out after the function test is finished;
b) the warning light shall display in the case
——where hydraulic failure occurs when the control force acting on the control is not more than 90 N; or
——where the liquid level in the reservoir of the brake master cylinder is lower than the followings, whichever is higher, when the control is not operated:
1) liquid level as specified in the vehicle technical specifications;
2) lower than or equal to half of the reservoir capacity.
c) The warning light shall remain displayed provided the fault is still present and the ignition switch is in the “ON” position.
4.6 Friction lining
4.6.1 Abrasion of the brake’s friction lining should be compensated by an automatic or manual adjustment device.
4.6.2 The abrasion of friction lining shall be observed without removing the brake. If unfulfillable, it should be inspected with an appropriate device.
4.6.3 During and after the test, the friction lining shall not be separated and the brake fluid shall not leak.
4.6.4 Materials of friction lining shall not contain asbestos.
4.7 Performance of brake system
4.7.1 Requirements for brake performance are given in Annex A.
4.7.2 Requirements for performance of the antilock brake system, if any, are given in Annex B.
4.7.3 Requirements for performance of the split service brake system, if any, for partial failure test are given in Annex C.
4.7.4 Requirements for performance of the power-assisted braking system, if any, for failure test are given in Annex D.
4.7.5 Requirements for performance of the combined brake system for failure test are given in Annex E.
5 Test
5.1 Test conditions
5.1.1 Requirements for test road
5.1.1.1 High friction surface
5.1.1.1.1 The test area shall keep clean and dry, and the test surface shall be flat with a gradient no more than 1%.
5.1.1.1.2 Unless otherwise specified, the peak braking coefficient of test surface is 0.9±0.1.
5.1.1.1.3 The test method for peak braking coefficient of high friction surface is given in Annex F.
5.1.1.2 Low friction surface
5.1.1.2.1 The test area shall keep clean, and the test surface shall be flat with a gradient no more than 1%.
5.1.1.2.2 The peak braking coefficient of test surface is not greater than 0.45.
5.1.1.2.3 The test method for peak braking coefficient of low friction surface is given in Annex F.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Requirements 5 Test 6 Implementation of this standard Annex A (Normative) Brake test and performance requirements Annex B (Normative) Antilock brake system test and performance requirements Annex C (Normative) Partial failure test and performance requirements of split service brake system Annex D (Normative) Failure test and performance requirements of power-assisted braking system Annex E (Normative) Failure test and performance requirements of combined brake system Annex F (Normative) Determination of peak braking coefficient
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
Chapters 1, 4 and 5, and annexes A to F of this standard are mandatory.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB 20073-2006 Performance and measurement method for braking of motorcycles and mopeds.
The following main changes have been made with respect to GB 20073-2006:
——the scope is modified where the "vehicles with the maximum design speed less than 25 km/h" is deleted (see Chapter 1 hereof, Chapter 1 of 2006 edition);
——the normative references are modified (see Chapter 2 hereof, Chapter 2 of 2006 edition);
——the terms and definitions of service brake system, secondary brake system, single brake system, split service brake system, power-assisted braking system, antilock brake system, wheel lock, peak braking coefficient, Vmax, engine disconnected, initial brake temperature, lightly loaded, test speed, stopping distance, baseline test and fully cycling are added (see Chapter 3 hereof);
——the terms and definitions of component(s) of a braking device, unladen vehicle and wet brake are deleted (see 3.5, 3.8 and 3.9 of 2006 edition);
——the requirements for functions and characteristics of brake system are modified (see 4.2 and 4.3 hereof, 4.1.2 and 4.2 of 2006 edition);
——the requirements for brake master cylinder, warning light and friction lining, and the performance requirements for brake system are added (see 4.4 to 4.7 hereof);
——the requirements for test road, environmental conditions, test speed, automatic gearbox, vehicle position, wheel lock and test sequence, and the test methods are modified (see Chapter 5 hereof, A.1.2 and A.1.3 of 2006 edition);
——the methods and performance requirements for running-in test, dry brake test of separately operated brake control, dry brake test of simultaneously operated brake control, high-speed brake test, failure test of split service brake system, failure test of power-assisted braking system, and failure test of combined brake system are added (see Annexes A to E hereof);
——the method and performance requirements for type 0 test of engine disconnected, two-wheeled motorcycles and engine connected are deleted (see A.1.4.2 and A.1.4.3 of 2006 edition);
——the methods for wet brake test and fade test are modified (see A.3.4 and A.3.6 hereof, A.1.4.4 and A.1.6 of 2006 edition);
——the applicable scope, method and performance requirements for parking brake system test are modified (see A.3.5 hereof, A.2.3 of 2006 edition);
——the method and performance requirements for antilock brake system test are modified (see Annex B hereof, Annex B and Annex C of 2006 edition);
——the method for measurement of peak braking coefficient on the test surface is added and written as a normative annex of this standard (see Annex F hereof).
This standard was proposed by and is under the jurisdiction of the Ministry of Industry and Information Technology of the People's Republic of China.
The previous editions of the standard replaced by this standard are as follows:
——GB 5382-1985;
——GB/T 5382.1-1996;
——GB 17355-1998;
——GB 20073-2006.
Performance and measurement method for braking of motorcycles and mopeds
1 Scope
This standard specifies requirements and test method for brake performance of motorcycles and mopeds.
This standard is applicable to motorcycles and mopeds.
This standard is not applicable to vehicles for the disabled.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
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 terms and definitions given in GB/T 15089-2001 for Category L vehicles and the followings apply.
3.1
brake system
a combination of components consisting of control, transmission, and brake, but excluding engine, whose function is to progressively reduce the speed of a moving vehicle, bring it to a halt, and keep it stationary when halted
3.2
control
a part actuated directly by the rider in order to supply or control the energy required for braking the vehicle to the transmission
3.3
transmission
a combination of components that provide the functional link between the control and the brake
3.4
brake
parts of the brake system where the forces opposing the movement of the vehicle are developed
3.5
service brake system
a brake system which slows down the vehicle when in motion
3.6
secondary brake system
second service brake system on a vehicle equipped with a combined brake system
3.7
single brake system
a brake system which acts on only one axle
3.8
combined brake system, CBS
a) for two-wheeled mopeds (Category L1) and motorcycles (Category L3), a service brake system where at least two brakes on different wheels are operated by the actuation of a single control
b) for three-wheeled mopeds (Category L2) and right three-wheeled motorcycles (Category L5), a service brake system where the brakes on all wheels are operated by the actuation of a single control
c) for motorcycles with sidecar (Category L4), a service brake system where the brakes on at least the front and rear wheels are operated by the actuation of a single control. If the rear wheel and sidecar wheel are braked by the same brake system, this is regarded as the rear brake.
3.9
split service brake system, SSBS
a brake system that operate the brakes on all wheels, consisting of two or more subsystems actuated by a single control designed so that a single failure in any subsystem (such as a leakage type failure of a hydraulic pipeline) does not impair the operation of any other subsystem
3.10
power-assisted braking system
a brake system in which the energy necessary to produce the braking force is supplied by the physical effort of the rider assisted by one or more energy supplying devices, for example vacuum assisted braking system (with vacuum booster)
3.11
antilock brake system, ABS
a system which senses wheel slip and automatically modulates the pressure producing the braking forces at the wheel(s) to limit the degree of wheel slip
3.12
wheel lock
a condition that occurs when there is a slip ratio of 1.00
3.13
peak braking coefficient, PBC
measure of tyre to road surface friction based on the maximum deceleration of a rolling tyre
3.14
Vmax
maximum speed measured in accordance with the method given in GB/T 5378
3.15
engine disconnected
disconnection of the engine from the driving wheel(s)
3.16
initial brake temperature
temperature of the brake before any brake application. If more than one brakes are operated simultaneously, the temperature of the hottest brake shall be selected.
3.17
laden
so loaded as to attain the maximum mass as defined by the manufacturer (in accordance with GB/T 5359.4)
3.18
lightly loaded
sum of the complete vehicle kerb mass (in accordance with GB/T 5359.4), rider mass (75 kg) and the mass of test equipment (15 kg), or the laden mass, whichever is less
In the case of ABS tests on a low friction surface, the mass of test equipment (including protective supports) is 30 kg.
3.19
test speed
vehicle speed measured at the moment the rider begins to actuate the brake control(s). For tests where the simultaneous actuation of two controls is specified, the vehicle speed is taken from the point the first control is actuated.
3.20
stopping distance
distance traveled by the vehicle from the point the rider begins to actuate the brake control to the point at which the vehicle reaches a full stop. For tests where the simultaneous actuation of two controls is specified, the vehicle speed is taken from the point the first control is actuated.
3.21
baseline test
a brake test or a series of brake tests carried out in order to confirm the performance of the brake prior to subjecting it to a further test such as the heat fade test or wet brake test
3.22
fully cycling
a process where the ABS repeatedly or continuously modulates the braking force in order to prevent directly actuated wheel lock
4 Requirements
4.1 General
The vehicle shall comply with the test requirements specified by its type and brake system characteristics.
4.2 Functions of brake system
4.2.1 Service brake system
The rider shall be able to actuate the service brake system control on the normal riding position without removing his hands from the handlebar (or steering control).
4.2.2 Secondary brake system (if any)
The rider shall be able to actuate the secondary brake system control on the normal riding position with at least one hand holding the handlebar (or steering control).
4.2.3 Parking brake system (if any)
4.2.3.1 The parking brake system fitted to the vehicle, if any, shall stabilize the vehicle on the test ramp as described in 5.1.1.3.
4.2.3.2 The parking brake system shall
a) comprise a control which is isolated from the service brake system control;
b) lock the working parts only in a purely mechanical manner.
4.2.3.3 The rider shall be able to actuate the parking brake system on the normal riding position.
4.2.3.4 The parking brake system fitted to three-wheeled mopeds (Category L2), motorcycles with sidecar (Category L4) and right three-wheeled motorcycles (Category L5) shall be tested according to Annex A, A.3.5, and shall meet the performance requirements.
4.3 Characteristics of brake system
4.3.1 Two-wheeled mopeds (Category L1) and motorcycles (Category L3) shall be fitted with two independent service brake systems or a split service brake system, with at least one brake controlling the front wheel and the other controlling 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 150 mL and less than or equal to 250 mL shall be fitted with antilock brake system or combined brake system;
b) Two-wheeled motorcycles (Category L3) with an actual engine displacement greater than 250 mL shall be fitted with antilock brake system on the front and rear wheels.
4.3.3 Motorcycles with sidecar (Category L4) shall comply with the requirements of 4.3.1. If the performance requirements specified in each test are met, brake is not required for the sidecar.
4.3.4 Three-wheeled mopeds (Category L2) shall be fitted with a parking brake system and one of the following brake systems:
——two independent service brake systems (except for combined brake system), which can control the brakes on all wheels concurrently;
——a split service brake system; or
——a combined brake system that can control the brakes on all wheels, and a secondary brake system or parking brake system.
4.3.5 Right three-wheeled motorcycles (Category L5) shall be fitted with a parking brake system and a foot-operated service brake system for controlling the brakes on all wheels which may be
——a split service brake system; or
——a combined brake system and a secondary brake system which may be a parking brake system.
4.3.6 If the requirements of failure test for combined brake system are met, two independent service brake systems can share the same brake and transmission.
4.4 Brake master cylinder
For vehicles using hydraulic transmission, the brake master cylinder shall comply with the following requirements:
——each brake system shall have an independent sealed and covered reservoir;
——the minimum capacity of the reservoir shall be 1.5 times the liquid volume required for the brake’s friction lining to be adjusted from a brand new state to a completely worn state;
——the liquid level should be inspected without opening the reservoir.
4.5 Warning light
4.5.1 Warning light of the brake system shall be so arranged as to be convenient for the rider to observe and identify on the normal operating position.
4.5.2 Vehicles equipped with an antilock brake system shall be fitted with a yellow warning light:
a) the warning light shall work when the vehicle’s ignition switch is turned on, and go out after the function test is finished;
b) the warning light shall display when the antilock brake system fails and affects the generation and transmission of system signals. The warning light shall remain displayed provided the fault is still present and the ignition switch is in the “ON” position.
4.5.3 Vehicles equipped with a split service brake system shall be fitted with a red warning light:
a) the warning light shall work when the vehicle’s ignition switch is turned on, and go out after the function test is finished;
b) the warning light shall display in the case
——where hydraulic failure occurs when the control force acting on the control is not more than 90 N; or
——where the liquid level in the reservoir of the brake master cylinder is lower than the followings, whichever is higher, when the control is not operated:
1) liquid level as specified in the vehicle technical specifications;
2) lower than or equal to half of the reservoir capacity.
c) The warning light shall remain displayed provided the fault is still present and the ignition switch is in the “ON” position.
4.6 Friction lining
4.6.1 Abrasion of the brake’s friction lining should be compensated by an automatic or manual adjustment device.
4.6.2 The abrasion of friction lining shall be observed without removing the brake. If unfulfillable, it should be inspected with an appropriate device.
4.6.3 During and after the test, the friction lining shall not be separated and the brake fluid shall not leak.
4.6.4 Materials of friction lining shall not contain asbestos.
4.7 Performance of brake system
4.7.1 Requirements for brake performance are given in Annex A.
4.7.2 Requirements for performance of the antilock brake system, if any, are given in Annex B.
4.7.3 Requirements for performance of the split service brake system, if any, for partial failure test are given in Annex C.
4.7.4 Requirements for performance of the power-assisted braking system, if any, for failure test are given in Annex D.
4.7.5 Requirements for performance of the combined brake system for failure test are given in Annex E.
5 Test
5.1 Test conditions
5.1.1 Requirements for test road
5.1.1.1 High friction surface
5.1.1.1.1 The test area shall keep clean and dry, and the test surface shall be flat with a gradient no more than 1%.
5.1.1.1.2 Unless otherwise specified, the peak braking coefficient of test surface is 0.9±0.1.
5.1.1.1.3 The test method for peak braking coefficient of high friction surface is given in Annex F.
5.1.1.2 Low friction surface
5.1.1.2.1 The test area shall keep clean, and the test surface shall be flat with a gradient no more than 1%.
5.1.1.2.2 The peak braking coefficient of test surface is not greater than 0.45.
5.1.1.2.3 The test method for peak braking coefficient of low friction surface is given in Annex F.
Contents of GB 20073-2018
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
5 Test
6 Implementation of this standard
Annex A (Normative) Brake test and performance requirements
Annex B (Normative) Antilock brake system test and performance requirements
Annex C (Normative) Partial failure test and performance requirements of split service brake system
Annex D (Normative) Failure test and performance requirements of power-assisted braking system
Annex E (Normative) Failure test and performance requirements of combined brake system
Annex F (Normative) Determination of peak braking coefficient
