Regulation No. 41-04

Name:Regulation No. 41-04
Description:Noise - Motorcycles
Official Title:Uniform Provisions Concerning the Approval of: Motorcycles with Regard to Noise.
Country:ECE - United Nations
Date of Issue:2012-08-14
Amendment Level:04 Series, Supplement 5
Number of Pages:54
Vehicle Types:Motorcycle
Subject Categories:Noise
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Keywords:

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Text Extract:

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E/ECE/324
) Rev.1/Add.40/Rev.2/Amend.5
E/ECE/TRANS/505 )
February 22, 2017
STATUS OF UNITED NATIONS REGULATION
ECE 41-04
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF:
MOTORCYCLES WITH REGARD TO NOISE
Incorporating:
02 series of amendments
Date of Entry into Force: 01.04.94
03 series of amendments
Date of Entry into Force: 05.02.00
Supplement 1 to the 03 series of amendments
Date of Entry into Force: 10.10.06
Corr. 1 to Revision 1 of the Regulation
Date of Entry into Force: 25.06.08
04 series of amendments
Date of Entry into Force: 13.04.12
Supplement 1 to the 04 series of amendments
Date of Entry into Force: 09.10.14
Supplement 2 to the 04 series of amendments
Date of Entry into Force: 08.10.15
Supplement 3 to the 04 series of amendments
Date of Entry into Force: 20.01.16
Supplement 4 to the 04 series of amendments
Date of Entry into Force: 08.10.16
Supplement 5 to the 04 series of amendments
Date of Entry into Force: 09.02.17

REGULATION No. 41-04
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF MOTORCYCLES
WITH REGARD TO NOISE
CONTENTS
1.
Scope
2.
Definitions, terms and symbols
3.
Application for Approval
4.
Markings
5.
Approval
6.
Specifications
7.
Modifications and Extension of the Approval of the Motorcycle Type or of the Type of
Exhaust or Silencing System(s)
8.
Conformity of Production
9.
Penalties for Non-conformity of Production
10.
Production Definitively Discontinued
11.
Names and Addresses of Technical Services Responsible for Conducting Approval Tests,
and of Type Approval Authorities
12.
Transitional Provisions
ANNEXES
Annex 1 – Communication
Annex 2 – Arrangements of approval marks.
Annex 3 – Methods and instruments for measuring noise made by motorcycles.
Appendix 1:
Appendix 2:
Flowchart of the test procedure for the test of the vehicle in motion for
vehicles of Category L with PMR ≤ 25
Positioning of the microphones for the stationary noise test
Annex 4 – Specifications for the test site
Annex 5 – Exhaust or silencing systems containing fibrous material
Annex 6 – Maximum limits of sound levels
Annex 7 – Additional Sound Emission Provisions (ASEP)
Annex 8 – Statement of compliance with the Additional Sound Emission Provisions (ASEP)

2.5. "Component of an exhaust or silencing system" means one of the individual components
which together form the exhaust system (such as exhaust pipework, the silencer proper) and
the intake system (air filter) if any.
If the engine has to be equipped with an intake system (air filter and/or intake noise absorber)
in order to comply with the maximum permissible sound levels, the filter and/or absorber shall
be treated as components having the same importance as the exhaust system.
2.6. "Kerb mass" (as defined in Section 4.1.2 of ISO 6726:1988) means the mass of the vehicle
ready for normal operation and fitted with the following equipment:
(a)
(b)
(c)
(d)
Full electrical equipment including the lighting and signalling devices supplied by the
manufacturer;
All instruments and fittings required by any legislation in respect of which a
measurement of the vehicle dry mass is being made;
Full complement of liquids to ensure the correct functioning of every part of the vehicle
and the fuel tank filled at least to 90% of the capacity specified by the manufacturer;
Auxiliary equipment usually supplied by the manufacturer in addition to that necessary
for normal operation (tool-kit, carrier(s), windscreen(s), protective equipment, etc.)
Notes:
1. In the case of a vehicle which operates on a fuel/oil mixture:
1.1. Where the fuel and oil are premixed, the word "fuel" is interpreted as including such
premixture of fuel and oil;
1.2. Where the fuel and oil are separately metered, the word "fuel" is interpreted as
including only the petrol. [The "oil", in this case, is already included in subparagraph (c)
of this Paragraph.]
2.7. "Rated maximum net power" means the rated engine power as defined in ISO 4106:2004.
The Symbol P denotes the numerical value of the rated maximum net power expressed in
kilowatts.
2.8. "Rated engine speed" means the engine speed at which the engine develops its rated
maximum net power as stated by the manufacturer.
The Symbol "S" denotes the numerical value of the rated engine speed expressed in
revolutions per minute .

2.13. Following is a table containing all symbols used in this Regulation:
Symbol
Units
Explanation
Reference
AA'

virtual line on the test track
Annex 4 – Figure 1
a
m/s
calculated acceleration
Annex 3 – 1.4.2.
a
m/s
prescribed reference acceleration Annex 3 – 1.3.3.3.1.2.
a
m/s
prescribed target acceleration
Annex 3 – 1.3.3.3.1.2.
BB'

virtual line on the test track
Annex 4 – Figure 1
CC'

virtual line on the test track
Annex 4 – Figure 1
k

gear weighting factor
Annex 3 – 1.4.3.
k

partial power factor
Annex 3 – 1.4.4.
L
dB(A)
sound pressure level
Annex 3 – 1.4.1.
L
dB(A)
L at wot condition
Annex 3 – 1.4.6.
I
m
pre-acceleration length
Annex 3 – 1.3.3.1.1.
m
kg
kerb mass of the vehicle
2.6.
m
kg
test mass of the vehicle
Annex 3 – 1.3.2.2.
n
min
engine speed
n
min
engine speed at PP'
Annex 7 – 2.6.
n
min
engine speed at idle

n
min
n
measured at L
detection
Annex 7 – 2.6.
PP'

virtual line on the test track
Annex 4 – Figure 1
PMR

power-to-mass ratio index
2.9.
P
kW
rated maximum net power
2.7.
S
min
rated engine speed
2.8.
v
km/h
measured vehicle speed

v
km/h
maximum speed
2.10.
v
km/h
prescribed test speed
Annex 3 – 1.3.3.1.1.

3.2.5. Cross-sectional drawings indicating the dimensions of the exhaust system. A copy of these
drawings shall be appended to the certificate referred to in Annex 1.
3.3. At the request of the Technical Service responsible for conducting approval tests, the
motorcycle manufacturer shall, in addition, submit a sample of the exhaust or silencing
system.
3.4. A motorcycle representative of the motorcycle type to be approved shall be submitted to the
Technical Service responsible for conducting approval tests.
3.5. A test report from the Technical Service conducting the type approval test shall be submitted
to the Type Approval Authority. This test report shall at least include the following information:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
Details of the test site (e.g. surface temperature, absorption coefficient, etc.), test site
location, site orientation and weather conditions including wind speed and air
temperature, direction, barometric pressure, humidity;
The type of measuring equipment including the windscreen;
The A-weighted sound pressure level typical of the background noise;
The identification of the vehicle, its engine, its transmission system, including available
transmission ratios, size and type of tyres, tyre pressure, type approval number of the
tyres (if available) or tyre manufacturer and commercial description of the tyres
(i.e. trade name, speed index, load index), rated maximum net power, test mass, power
to mass ratio index, a , a , vehicle length;
The transmission gears or gear ratios used during the test;
The vehicle speed and engine speed at the beginning of the period of acceleration and
the location of the beginning of the acceleration per gear used;
The vehicle speed and engine speed at PP' and at the end of the acceleration per valid
measurement;
The method used for calculation of the acceleration;
(i)
The intermediate measurement results a
, a
, L
, L
, L
and L
,
if applicable;
(j) The weighting factors k and k and the final measurement results L , L and L ;
(k)
(l)
(m)
The auxiliary equipment of the vehicle, where appropriate, and its operating conditions;
All valid A-weighted sound pressure level values measured for each test, listed
according to the side of the vehicle and the direction of the vehicle movement on the
test site; and
All relevant information necessary to obtain the different sound emission levels.

5.4. There shall be affixed, conspicuously and in a readily accessible place specified on the
approval form, to every motorcycle conforming to a motorcycle type approved under this
Regulation an international approval mark consisting of:
5.4.1. A circle surrounding the Letter "E" followed by the distinguishing number of the country which
has granted approval ; and
5.4.2. The number of this Regulation, followed by the Letter "R", a dash and the approval number to
the right of the circle prescribed in Paragraph 5.4.1.
5.5. If the motorcycle conforms to a motorcycle type approved, under one or more other
Regulations annexed to the Agreement, in the country which has granted approval under this
Regulation, the symbol prescribed in Paragraph 5.4.1. need not be repeated; in such a case
the Regulation and approval numbers and the additional symbols of all the Regulations under
which approval has been granted in the country which has granted approval under this
Regulation shall be placed in vertical columns to the right of the symbol prescribed in
Paragraph 5.4.1.
5.6. The approval mark shall be clearly legible and be indelible.
5.7. The approval mark shall be placed close to or on the motorcycle data plate affixed by the
manufacturer.
5.8. Annex 2 to this Regulation gives examples of arrangements of the approval mark.
6. SPECIFICATIONS
6.1. General Specifications
6.1.1. The following information shall be provided on the motorcycle in an easily accessible but not
necessarily immediately visible location:
(a)
(b)
The manufacturer's name;
The target engine speed and the final result of the stationary test as defined in
Paragraph 2. of Annex 3 to this Regulation;
In addition for motorcycles of Category L with PMR > 50 the in-use compliance
reference data as defined in Paragraph 3. of Annex 3 to this Regulation shall be
displayed. This data can be provided either in one single location together with the
information in 6.1.1.(a) and 6.1.1.(b) or in a second different location together with the
information in 6.1.1.(a) .

6.5. Additional prescriptions related to tamper ability and manually adjustable multi-mode exhaust
or silencing systems
6.5.1. All exhaust or silencing systems shall be constructed in a way that does not easily permit
removal of baffles, exit-cones and other parts whose primary function is as part of the
silencing/expansion chambers. Where incorporation of such a part is unavoidable, its method
of attachment shall be such that removal is not facilitated easily (e.g. with conventional
threaded fixings) and should also be attached such that removal causes
permanent/irrecoverable damage to the assembly.
6.5.2. Exhaust or silencing systems with multiple, manually adjustable operating modes shall meet
all requirements in all operating modes. The reported noise levels shall be those resulting
from the mode with the highest noise levels.
7. MODIFICATION AND EXTENSION OF THE APPROVAL OF THE MOTORCYCLE TYPE
OR OF THE TYPE OF EXHAUST OR SILENCING SYSTEM(S)
7.1. Every modification of the motorcycle type or of the exhaust or silencing system shall be
notified to the Type Approval Authority which approved the motorcycle type. The Type
Approval Authority may then either:
7.1.1. Consider that the modifications made are unlikely to have appreciable adverse effects, and
that in any case the motorcycle still complies with the requirements of this Regulation; or
7.1.2. Require a further test report from the Technical Service responsible for conducting the tests.
7.2. Confirmation or refusal of approval, specifying the alterations, shall be communicated by the
procedure specified in Paragraph 5.3. above to the Parties to the Agreement which apply this
Regulation.
7.3. The competent authority which issued the approval extension shall assign a serial number to
the extension and shall so notify the other Parties to the 1958 Agreement applying this
Regulation, by means of a communication form conforming to the model in Annex 1 to this
Regulation.
8. CONFORMITY OF PRODUCTION
The conformity of production procedures shall comply with those set out in the Agreement,
Appendix 2 (E/ECE/324-E/ECE/TRANS/505/Rev.2), with the following requirements:
8.1. Any motorcycle manufactured shall conform to a type of motorcycle approved pursuant to this
Regulation, be equipped with the silencer with which it was type approved and satisfy the
requirements of Paragraph 6 above.
8.2. In order to test conformity as required above, a sample motorcycle will be taken from the
production line of the type approved pursuant to this Regulation. Its sound levels measured
and processed (L and L ) according to the method described in Annex 3, with the same
gear(s) and pre-acceleration distance(s) as used in the original type approval test, and
mathematically rounded to the nearest integer shall not exceed by more than 3.0dB(A) the
values measured and processed at the time of type approval. Furthermore, L shall not
exceed by more than 1.0dB(A) the limit laid down in Annex 6 of this Regulation, and L , in
connection with 6.2.3., shall not exceed the limit value for L by more than 6.0 dB(A).

12.5. Approvals granted under this Regulation before the date in Paragraph 12.2. and all
extensions of such approvals, including those granted subsequently under a preceding series
of amendments to this Regulation, shall remain valid indefinitely. If the motorcycle type
approved under the preceding series of amendments meets the requirements of this
Regulation as amended by the 04 series of amendments, the Contracting Party which granted
the approval shall so notify the other Contracting Parties applying this Regulation.
12.6. No Contracting Party applying this Regulation shall refuse national type approval of a
motorcycle type approved under the 04 series of amendments to this Regulation or meeting
the requirements thereof.
12.7. As from January 1, 2017 Contracting Parties applying this Regulation may refuse first national
registration (first entry into service) of a motorcycle which does not meet the requirements of
the 04 series of amendments to this Regulation.
12.8. As from the official date of entry into force of Supplement 3 to the 04 series of amendments,
no Contracting Party applying this Regulation shall refuse to grant or refuse to accept type
approval according to Supplement 3 to 04 series of amendments to this Regulation.
12.9. As from 60 months after the date of entry into force of Supplement 3 to the 04 series of
amendments to this Regulation, Contracting Parties applying this Regulation shall grant type
approvals only if the vehicles type to be approved meets the requirements of this Regulation
as amended by Supplement 3 to the 04 series of amendments to this Regulation.

6. Transmission
6.1. Type of transmission: non-automatic gearbox/automatic gearbox: ..........................................
6.2. Number of gears: ......................................................................................................................
7. Equipment
7.1. Exhaust silencer
7.1.1. Manufacturer or authorized representative (if any): ..................................................................
7.1.2. Model: .......................................................................................................................................
7.1.3. Type: ..................................... in accordance with drawing No. ..............................................
7.2. Intake silencer
7.2.1. Manufacturer or authorized representative (if any): ..................................................................
7.2.2. Model: .......................................................................................................................................
7.2.3. Type: ..................................... in accordance with drawing No. ..............................................
8. Gears used for test of motorcycle in motion: ............................................................................
9. Final drive ratio(s): ....................................................................................................................
10. Type approval number of tyre(s): ..............................................................................................
If not available, the following information shall be provided:
10.1. Tyre manufacturer: ....................................................................................................................
10.2. Commercial description(s) of the type of tyre (by axle), (e.g. trade name, speed index, load
index): .......................................................................................................................................
10.3. Tyre size (by axle): ....................................................................................................................
10.4. Other type approval number (if available): ................................................................................
11. Masses
11.1. Maximum permissible gross weight: .................................................................................... kg
11.2. Test mass: ............................................................................................................................ kg
11.3. Power to mass ratio index (PMR): ............................................................................................
12. Vehicle length: ....................................................................................................................... m
12.1. Reference length l : ............................................................................................................. m

19. In-use compliance reference data
19.1. Gear (i) or, for vehicles tested with non-locked gear ratios, the position of the gear selector
chosen for the test: ....................................................................................................................
19.2. Pre-acceleration length l : ................................................................................................... m
19.3. Vehicle speed at the beginning of the period of acceleration (average of 3 runs) for
gear (i): ............................................................................................................................. km/h
19.4. Sound pressure level L : ............................................................................................ dB(A)
20. Date of submission of vehicle for approval: ..............................................................................
21. Technical Service performing the approval tests: .....................................................................
22. Date of report issued by that service .........................................................................................
23. Number of report issued by that service ....................................................................................
24. Approval granted/extended/refused/withdrawn .......................................................................
25. Place ..........................................................................................................................................
26. Date ............................................................................................................................................
27. Signature ....................................................................................................................................
28. Annexed to this communication are the following documents, bearing the approval number
indicated above:
Drawings, diagrams and plans of the engine and of the noise reduction system;
Photographs of the engine and of the exhaust or silencing system;
List of components, duly identified constituting the noise reduction system.

ANNEX 3
METHODS AND INSTRUMENTS FOR MEASURING NOISE MADE BY MOTORCYCLES
1. NOISE OF THE MOTORCYCLE IN MOTION (MEASURUING CONDITIONS AND
METHOD FOR TESTING OF THE VEHICLE DURING COMPONENT TYPE
APPROVAL).
1.1. Measuring Instruments
1.1.1. Acoustic Measurements
1.1.1.1. General
1.1.1.2. Calibration
The apparatus used for measuring the sound pressure level shall be a sound level meter
or equivalent measuring system meeting the requirements of Class 1 instruments
(inclusive of the recommended windscreen, if used). These requirements are described in
IEC 61672-1:2002.
Measurements shall be carried out using the time weighting "F" of the acoustic measuring
instrument and the "A" frequency weighting curve also described in IEC 61672-1:2002.
When using a system that includes periodic monitoring of the A-weighted sound pressure
level, a reading should be made at a time interval not greater than 30ms.
The instruments shall be maintained and calibrated in accordance with the instructions of
the instrument manufacturer.
At the beginning and at the end of every measurement session, the entire acoustic
measuring system shall be checked by means of a sound calibrator that fulfils the
requirements of Class 1 sound calibrators according to IEC 60942:2003. Without any
further adjustment, the difference between the readings shall be less than or equal to
0.5dB(A). If this value is exceeded, the results of the measurements obtained after the
previous satisfactory check shall be discarded.
1.1.1.3. Compliance with Requirements
Compliance of the sound calibrator with the requirements of IEC 60942:2003 shall be
verified once a year. Compliance of the instrumentation system with the requirements of
IEC 61672-1:2002 shall be verified at least every 2 years. All compliance testing shall be
conducted by a laboratory which is authorized to perform calibrations traceable to the
appropriate standards.

1.2.2. Meteorological Conditions
The meteorological instrumentation shall deliver data representative of the test site, and
shall be positioned adjacent to the test area at a height representative of the height of the
measuring microphone.
The measurements shall be made when the ambient air temperature is within the range
from 5°C to 45°C. The tests shall not be carried out if the wind speed, including gusts, at
microphone height exceeds 5m/s, during the noise measurement interval.
A value representative of temperature, wind speed and direction, relative humidity and
barometric pressure shall be recorded during the noise measurement interval.
1.2.3. Background Noise
Any sound peak which appears to be unrelated to the characteristics of the general noise
level of the vehicle shall be ignored in taking the readings.
The background noise shall be measured for a duration of 10s immediately before and
after a series of vehicle tests. The measurements shall be made with the same
microphones and microphone locations used during the test. The maximum A-weighted
sound pressure level shall be reported.
The background noise (including any wind noise) shall be at least 10dB(A) below the
A-weighted sound pressure level produced by the vehicle under test. If the difference
between the background sound pressure level and the measured sound pressure level is
between 10dB(A) and 15dB(A), in order to calculate the test result the appropriate
correction shall be subtracted from the readings on the sound level meter, as given in
Table 1.
Table 1
Correction Applied to Individual Measured Test Value
Background sound pressure level difference
to measured sound pressure level, in dB
10
11
12
13
14
≥ 15
Correction, in dB(A) 0.5 0.4 0.3 0.2 0.1 0.0
1.3. Test Procedures
1.3.1. Microphone Positions
The distance of the microphone positions from the Line CC', on the microphone Line PP',
perpendicular to the reference Line CC' on the test track (see Annex 4 – Figure 1), shall be
7.5 ± 0.05m.
The microphones shall be located 1.2 ± 0.02m above the ground level. The reference
direction for free-field conditions (see IEC 61672-1:2002) shall be horizontal and directed
perpendicularly towards the path of the vehicle Line CC'.

1.3.3.1.2. During constant speed tests, the acceleration control unit shall be positioned to maintain a
constant vehicle speed between the Lines AA' and BB'.
1.3.3.2. Operating conditions for vehicles with PMR ≤ 25
The vehicle is tested in a full throttle acceleration test with the following specifications:
(a) The test speed shall be v = 40 ± 1km/h.
(b)
When the rear of the vehicle passes the Line BB' the vehicle speed shall not exceed
75% of the maximum vehicle speed as defined in Paragraph 2.10. of this Regulation
neither shall the engine speed exceed the rated engine speed.
The gear for the test shall be selected in the following iterative way:
The initial test speed shall be as specified above. The test speed shall be reduced by
increments of 10% of v (i.e. 4km/h) in case the exit speed v exceeds 75% of v or in
case the engine speed exceeds the rated engine speed S at BB'. The selected gear shall
be the lowest one without exceeding the rated engine speed S during the test. The final
test conditions are determined by the lowest possible gear at the highest possible test
speed without exceeding either 75% of v or the rated engine speed "S" at BB'.
To save testing time, the manufacturer may provide information on the iterative procedure
for gear selection specified above.
A flow chart of the test procedure is given in Appendix 1 to this Annex.
1.3.3.3. Operating conditions for vehicles with PMR > 25
The vehicle is tested in a full throttle acceleration test and in a constant speed test.
1.3.3.3.1. Full Throttle Acceleration Test
1.3.3.3.1.1. Test Speed
For the full throttle acceleration tests the test speed and the mean acceleration of the
vehicle in the test track are specified.
The accelerations are not measured directly but calculated from measurements of the
vehicle speed as described in Paragraph 1.4. below.
The test speed v shall be:
40 ± 1km/h for vehicles with a PMR ≤ 50; and
50 ± 1km/h for vehicles with a PMR > 50.
If, in a given gear, the exit speed v exceeds 75% of the maximum speed v of the
vehicle, the test speed for test in this gear shall be successively reduced by increments of
10% of v (i.e. 4km/h or 5km/h) until the exit speed v falls below 75% of v .

1.3.3.3.1.3.2. Vehicles with automatic transmissions, adaptive transmissions or transmissions with
variable transmission ratios tested with non-locked gears
The gear selector position for full automatic operation shall be used.
The test may then include a gear change to a lower gear and a higher acceleration. A gear
change to a higher gear and a lower acceleration is not allowed. In any case, a gear
change to a gear which is typically not used at the specified condition in urban traffic shall
be avoided.
Therefore, it is permitted to establish and use electronic or mechanical devices, including
alternative gear selector positions, to prevent a downshift to a gear which is typically not
used at the specified test condition in urban traffic. If such devices are used, no
pre-acceleration may be applied. The functionality of the devices shall be described in the
communication form.
1.3.3.3.2. Constant Speed Test
For the constant speed tests the gears or gear selector positions and the test speeds shall
be identical to those used in the full throttle acceleration tests previously performed.
1.4. Data Processing and Reporting
1.4.1. General
At least three measurements for each test condition shall be made on each side of the
vehicle and for each gear.
The maximum A-weighted sound pressure level "L" indicated during each passage of the
vehicle between AA' and BB' (see Annex 4 – Figure 1) shall be reduced by 1dB(A) to
account for measurement inaccuracy and mathematically rounded to the nearest first
decimal place (e.g. XX.X) for both microphone positions. If a sound peak obviously out of
character with the general sound pressure level is observed, that measurement shall be
discarded.
The first three valid consecutive measurement results for each test condition, within
2.0dB(A), allowing for the deletion of non-valid results, shall be used for the calculation of
the appropriate intermediate or final result.
The speed measurements at AA' (v ), BB' (v ), and PP' (v ) shall be mathematically
rounded to the nearest first decimal place (e.g. XX.X) and noted for further calculations.

1.4.2.2. Calculation of the Acceleration between the Lines PP' and BB'
The acceleration is calculated from measurements of the vehicle speed at the Lines PP'
and BB':
a = ((v / 3.6) - (v / 3.6) ) / (2 * (10 + l ))
Where:
The index "(i)" refers to the gear used and the index "j" to the number of the individual
measurement. The velocities are expressed in units of km/h and the resulting
accelerations have units of m/s ;
l is either the length of vehicle or 2m, freely selectable by the vehicle manufacturer, type
approval authority and technical service.
Pre-acceleration shall not be used.
1.4.2.3. Averaging of Individual Measurements
The calculated accelerations from three valid runs are arithmetically averaged to give the
mean acceleration for the test condition:
a = (1 / 3) * (a + a + a )
The mean acceleration a shall be mathematically rounded to the nearest second
decimal place (e.g. XX.XX) and noted for further calculations.
1.4.3. Calculation of the Gear Weighting Factor
The gear weighting factor "k" is used only in the case of a two-gear test to combine the
results from both gears into a single result.
The gear weighting factor is a dimensionless number defined as:
k = (a - a ) / (a - a )
1.4.4. Calculation of the Partial Power Factor
The partial power factor k is a dimensionless number used to combine the results of a full
throttle acceleration test with those of a constant speed test.
1.4.4.1. For vehicles tested in two gears the partial power factor is defined as
k = 1 - (a / a ).
1.4.4.2. For vehicles tested in a single gear or with the gear selector in one position the partial
power factor is defined as:
k = 1 - (a / a )
If a is equal to or less than a , k is set to zero.

2. NOISE FROM STATIONARY MOTORCYCLE (MEASURING CONDITIONS AND
METHOD FOR TESTING OF THE VEHICLE IN USE).
2.1. Sound-pressure Level in the Immediate Vicinity of the Motorcycle
In order to facilitate subsequent noise tests on motorcycles in use, the sound-pressure
level shall also be measured in the immediate vicinity of the exhaust-system outlet in
accordance with the following requirements, the result of the measurement being entered
in the communication referred to in Annex 1.
2.2. Measuring Instruments
A precision sound level meter as defined in Paragraph 1.1.1. of this Annex shall be used.
2.3. Conditions of Measurement
2.3.1. Condition of the Motorcycle
The vehicle transmission shall be in neutral position and the clutch engaged, or in parking
position for automatic transmission, and the parking brake applied for safety, if equipped.
The vehicle air conditioner, if equipped, shall be turned off.
If the vehicle is fitted with fan(s) having an automatic actuating mechanism, this system
shall not be interfered with during the sound pressure level measurements.
The engine hood or compartment cover shall be closed.
Before each series of measurements, the engine shall be brought to its normal operating
temperature, as specified by the manufacturer.
In case of a two-wheeled motor-driven vehicle having no neutral gear position,
measurements shall be carried out with the rear wheel raised off the ground so that the
wheel can rotate freely.
If it is necessary to raise a two-wheeled vehicle off the ground to perform the test, the
microphone measurement position shall be adjusted to achieve the specified distance
from the reference point of the exhaust pipe; see Figure 1 for the location of the reference
points.

2.4. Method of Measurement
2.4.1. Positioning of the Microphone (see Appendix 2)
The microphone shall be located at a distance of 0.5 ± 0.01m from the reference point of
the exhaust pipe defined in Figure 1 and at an angle of 45 ± 5° to the vertical plane
containing the flow axis of the pipe termination. The microphone shall be at the height of
the reference point, but not less than 0.2m from the ground surface. The reference axis of
the microphone shall lie in a plane parallel to the ground surface and shall be directed
towards the reference point on the exhaust outlet.
The reference point shall be the highest point satisfying the following conditions:
(a)
(b)
The reference point shall be at the end of the exhaust pipe,
The reference point shall be on the vertical plane containing the exhaust outlet
centre and the flow axis of the exhaust pipe termination.
If two microphone positions are possible, the location farthest laterally from the vehicle
longitudinal centreline shall be used.
If the flow axis of the exhaust outlet pipe is at 90° ± 5° to the vehicle longitudinal
centreline, the microphone shall be located at the point that is the furthest from the engine.
If a vehicle has two or more exhaust outlets spaced less than 0.3m apart and connected to
a single silencer, only one measurement shall be made. The microphone shall be located
relative to the outlet the farthest from the vehicle's longitudinal centreline, or, when such
outlet does not exist, to the outlet that is highest above the ground.
For vehicles having an exhaust provided with outlets spaced more than 0.3m apart, one
measurement is made for each outlet as if it were the only one, and the highest sound
pressure level shall be noted.
For the purpose of roadside checking, the reference point may be moved to the outer
surface of the vehicle body.

2.4.3. Multi-mode Exhaust System
2.5. Results
Vehicles equipped with a multiple mode, manually adjustable exhaust system shall be
tested in all modes.
2.5.1. The Communication referred to in Annex 1 shall indicate all relevant data and particularly
those used in measuring the noise of the stationary motorcycle.
2.5.2. Measurements shall be made at the microphone location(s) prescribed above. The
maximum A-weighted sound pressure level indicated during the test shall be noted,
retaining one significant figure behind the decimal place (e.g. 92.45 shall be noted as to
92.5 while 92.44 shall be noted as to 92.4).
The test shall be repeated until three consecutive measurements that are within 2.0dB(A)
of each other are obtained at each outlet.
2.5.3. The result for a given outlet is the arithmetic average of the three valid measurements,
mathematically rounded to the nearest integer value (e.g. 92.5 shall be noted as to 93
while 92.4 shall be noted as to 92).
2.5.4. For vehicles equipped with multiple exhaust outlets, the reported sound pressure level
shall be for the outlet having the highest average sound pressure level.
2.5.5. For vehicles equipped with a multi-mode exhaust system and a manual exhaust mode
control the reported sound pressure level shall be for the mode having the highest average
sound pressure level.
3. NOISE FROM THE MOTORCYCLE IN MOTION (DATA REPORTED TO FACILITATE
TESTING OF THE VEHICLE IN USE)
3.1. A test procedure for in-use compliance tests may be defined by a Contracting Party, taking
due account of any differences from the test conditions used at type-approval.
3.2. In order to facilitate in-use compliance test of motorcycles, the following information
relating to the sound-pressure level measurements carried out in accordance with
Paragraph 1. of Annex 3 for the motorcycle in motion is referred to as in-use compliance
reference data:
(a)
Gear (i) or, for vehicles tested with non-locked gear ratios, the position of the gear
selector chosen for the test;
(b) The pre-acceleration length l in m;
(c)
The average vehicle speed in km/h at the beginning of the full throttle acceleration
for tests in gear (i); and
(d) The sound pressure level L in dB(A) of the wide-open-throttle tests in gear (i),
defined as the maximum of the two values resulting from averaging the individual
measurement results at each microphone position separately.
3.3. The in-use compliance reference data shall be entered in the communication form
conforming to Annex 1.

ANNEX 3 - APPENDIX 2
POSITIONING OF THE MICROPHONES FOR THE STATIONARY NOISE TEST
Dimensions in metres, unless otherwise indicated

2.5. Periodic Testing
In order to check whether the surface continues to conform to the texture and voids content
or sound absorption requirements stipulated in this standard, periodic testing of the surface
shall be done at the following intervals:
(a)
For residual voids content or sound absorption:
When the surface is new;
If the surface meets the requirements when new, no further periodical testing is
required.
(b)
For texture depth (TD):
When the surface is new;
When the noise testing starts (NB: not before four weeks after laying);
Then every 12 months.
3. TEST SURFACE DESIGN
3.1. Area
When designing the test track layout it is important to ensure that, as a minimum
requirement, the area traversed by the vehicles running through the test strip is covered with
the specified test material with suitable margins for safe and practical driving. This will
require that the width of the track is at least 3m and the length of the track extends beyond
Lines AA and BB by at least 10m at either end. Figure 1 shows a plan of a suitable test site
and indicates the minimum area which shall be machine laid and machine compacted with
the specified test surface material. According to Paragraph 1.3.1. of Annex 3 measurements
have to be made on each side of the vehicle. This can be made either by measuring with
two microphone locations (one on each side of the track) and driving in one direction, or
measuring with a microphone only on one side of the track but driving the vehicle in two
directions. If the latter method is used, then there are no surface requirements on that side
of the track where there is no microphone.

3.2.2. Design Guidelines
As a guide to the surface constructor, an aggregate grading curve which will give desired
characteristics is shown in Figure 2. In addition, Table 1 gives some guidelines in order to
obtain the desired texture and durability. The grading curve fits the following formula:
P (percent passing) = 100 * (d / d )
Where:
d
= square mesh sieve size, in mm
d = 8mm for the mean curve
d = 10mm for the lower tolerance curve
d = 6.3mm for the upper tolerance curve
Figure 2
Grading Curve of the Aggregate in the Asphaltic Mix with Tolerances

4. TEST METHOD
4.1. Measurement of the Residual Voids Content
For the purpose of this measurement, cores have to be taken from the track in at least four
different positions which are equally distributed in the test area between Lines AA and BB
(see Figure 1). In order to avoid inhomogeneity and unevenness in the wheel tracks, cores
should not be taken in wheel tracks themselves, but close to them. Two cores (minimum)
should be taken close to the wheel tracks and one core (minimum) should be taken
approximately midway between the wheel tracks and each microphone location.
If there is a suspicion that the condition of homogeneity is not met (see Paragraph 2.4.),
cores shall be taken from more locations within the test area. The residual voids content has
to be determined for each core, then the average value from all cores shall be calculated
and compared with the requirement of Paragraph 2.1. In addition, no single core shall have
a voids value which is higher than 10%. The test surface constructor is reminded of the
problem which may arise when the test area is heated by pipes or electrical wires and cores
shall be taken from this area. Such installations shall be carefully planned with respect to
future core drilling locations. It is recommended to leave a few locations of size
approximately 200* 300mm where there are no wires/pipes or where the latter are located
deep enough in order not to be damaged by cores taken from the surface layer.
4.2. Sound Absorption Coefficient
The sound absorption coefficient (normal incidence) shall be measured by the impedance
tube method using the procedure specified in ISO 10534:1994 – "Acoustics – Determination
of sound absorption coefficient and impedance by a tube method."
Regarding test specimens, the same requirements shall be followed as regarding the
residual voids content (see Paragraph 4.1.). The sound absorption shall be measured in the
range between 400Hz and 800Hz and in the range between 800Hz and 1.600Hz (at least at
the centre frequencies of third octave bands) and the maximum values shall be identified for
both of these frequency ranges. Then these values, for all test cores, shall be averaged to
constitute the final result.
4.3. Volumetric Macro Texture Measurement
For the purpose of this standard, texture depth measurements shall be made on at least
10 positions evenly spaced along the wheel tracks of the test strip and the average value
taken to compare with the specified minimum texture depth. For the description of the
procedure see standard ISO 10844:1994.

6.1.6. All or at least the latest test results, including:
6.1.6.1. The residual voids content of each core.
6.1.6.2. The locations in the test area from where the cores for voids measurements have been
taken.
6.1.6.3. The sound absorption coefficient of each core (if measured). Specify the results both for
each core and each frequency range as well as the overall average.
6.1.6.4. The locations in the test area from where the cores for absorption measurement have been
taken.
6.1.6.5. Texture depth, including the number of tests and standard deviation.
6.1.6.6. The institution responsible for the tests according to Paragraphs 6.1.6.1. and 6.1.6.2. and
the type of equipment used.
6.1.6.7. Date of the test(s) and date when the cores were taken from the test track.
6.2. Documentation of Vehicle Noise Tests Conducted on the Surface
In the document describing the vehicle noise test(s) it shall be stated whether all the
requirements of this standard were fulfilled or not. Reference shall be given to a document
according to Paragraph 6.1. describing the results which verify this.

1.3.1.3. The two speed regimes shall be alternated at least six times.
1.3.1.4. The complete test programme shall include a minimum of 10 breaks of at least 3h' duration
in order to reproduce the effects of cooling and condensation.
1.3.2. Conditioning by Pulsation
1.3.2.1. The exhaust system or components thereof shall be fitted to the motorcycle or to the engine.
In the former case, the motorcycle shall be mounted on a test bench.
The test apparatus, a detailed diagram of which is shown in Figure 1, is fitted at the outlet of
the exhaust system. Any other apparatus providing equivalent results is acceptable.
1.3.2.2. The test equipment shall be adjusted so that the flow of exhaust gases is alternatively
interrupted and restored 2,500 times by a rapid-action valve.
1.3.2.3. The valve shall open when the exhaust gas back-pressure, measured at least 100mm
downstream of the intake flange, reaches a value of between 35 and 40kPa. Should such a
figure be unattainable because of the engine characteristics, the valve shall open when the
gas back-pressure reaches a level equivalent to 90% of the maximum that can be measured
before the engine stops. It shall close when this pressure does not differ by more than 10%
from its stabilized value with the valve open.
1.3.2.4. The time-delay switch shall be set for the duration of exhaust gases calculated on the basis
of the requirements of Paragraph 1.3.2.3.
1.3.2.5. Engine speed shall be 75% of the rated engine speed (S).
1.3.2.6. The power indicated by the dynamometer shall be 50% of the full-throttle power measured
at 75% of the rated engine speed (S).
1.3.2.7. Any drainage holes shall be closed off during the test.
1.3.2.8. The entire test shall be complete within 48h. If necessary, a cooling period shall be allowed
after each hour.
1.3.3. Conditioning on a Test Bench
1.3.3.1. The exhaust system shall be fitted to an engine representative of the type fitted to the
motorcycle for which the exhaust system was designed, and mounted on a test bench.
1.3.3.2. Conditioning consists of the specific number of test bench cycles for each class of
motorcycle for which the exhaust system was designed. The number of cycles for each
class of motorcycle is:
Class of motorcycle according to Power-to-Mass Ratio index (PMR)
Class I ≤ 25
Class II > 25 ≤ 50
Class III > 50
Number of cycles
6
9
12

Figure 1
Test Apparatus For Conditioning By Pulsation
Notes:
1. Inlet flange or sleeve for connection to the rear of the test exhaust system.
2. Hand-operated regulating valve.
3. Compensating reservoir with a maximum capacity of 40 litres.
4. Pressure switch with an operating range of 5kPa to 250kPa.
5. Time delay switch.
6. Impulse counter.
7. Quick response valve, such as exhaust brake valve 60mm in diameter, operated by a
pneumatic cylinder with an output of 120N at 400kPa. The response time, both when
opening and closing, must not exceed 0.5s.
8. Exhaust gas evacuation.
9. Flexible pipe.
10. Pressure gauge.
1.4. Exhaust gases are not in contact with fibrous materials and fibrous materials are not under the
influence of pressure variations

ANNEX 7
ADDITIONAL SOUND EMISSION PROVISIONS (ASEP)
1. SCOPE
1.1. This Annex applies to vehicles of Category L with PMR >50.
1.2. Vehicles with variable gear ratios or automatic transmission with non-lockable gear ratios
are exempted from the requirements of this Annex, if the vehicle manufacturer provides
technical documents to the type approval authority showing, that the vehicle's engine speed
at BB' does neither exceed n + 0.05 * (S – n ) nor fall below n – 0.05 * (S – n ) for
any test condition inside the ASEP control range defined in Paragraph 2.5. below, where
n is the average engine speed at BB' from the three valid acceleration tests according to
Paragraph 1. of Annex 3.
2. ADDITIONAL SOUND EMISSION REQUIREMENTS
2.1. Measuring Instruments
The requirements for the measurement equipment are identical to those defined in
Paragraph 1.1. of Annex 3 for the tests of the motorcycle in motion.
2.2. Acoustical Environment, Meteorological Conditions and Background Noise
The requirements concerning the acoustical environment, the meteorological conditions and
the background noise are identical to those defined in Paragraph 1.2. of Annex 3 for the
tests of the motorcycle in motion.
2.3. Microphone Positions and Conditions of the Vehicle
The requirements concerning the microphone positions and the conditions of the vehicle are
identical to those defined in Paragraphs 1.3.1. and 1.3.2. of Annex 3 for the tests of the
motorcycle in motion.
2.4. General Operating Conditions
The general operating conditions are identical to those defined in Paragraph 1.3.3.1. of
Annex 3 for the tests of the motorcycle in motion.
2.5. ASEP Control Range
The requirements of this Annex apply to any vehicle operation with the following restrictions:
(a) v shall be at least 20km/h
(b) v shall not exceed 80km/h
(c) n shall be at least 0.1 * (S – n ) + n
(d) n shall not exceed
0.85 * (S – n ) + n for PMR ≤ 66 and
3.4 * PMR * (S – n ) + n for PMR > 66
Note: If the vehicle has more than one gear, the first gear shall not be used

3.2.2. Test Speed and Gear Selection
The vehicle shall be tested at each of the following operating conditions:
(i) v = 50km/h
The selected gear (i) and pre-acceleration condition shall be the same as those used
in the original type approval test of Annex 3 of this Regulation.
(ii) v corresponding to
n = 0.85 * (S – n ) + n for PMR ≤ 66; and
n = 3.4 * PMR * (S – n ) + n for PMR > 66
v shall not exceed 80km/h
The selected gear shall be 2nd. If the 3rd gear satisfies requirements of n
and v
,
3rd shall be used. If the 4th gear satisfies requirements of n
and v
, 4th shall be
used.
3.2.3. Data Processing and Reporting
The requirements of Paragraph 1.4. of Annex 3 shall be applied.
In addition the engine speed values at AA', BB', and PP' in units of min shall be
mathematically rounded to the nearest integer for further calculations. For a given test
condition the three individual engine speeds shall be averaged arithmetically.
The final sound pressure levels for the full throttle acceleration shall not exceed the limits
specified in Paragraph 2.6. above.

Noise - Motorcycles