Regulation No. 41-03

Name:Regulation No. 41-03
Description:Noise - Motorcycles.
Official Title:Uniform Provisions Concerning the Approval of: Motorcycles with Regard to Noise.
Country:ECE - United Nations
Date of Issue:1980-05-14
Amendment Level:03 Series, Revision 1, Corrigendum 1
Number of Pages:35
Vehicle Types:Motorcycle
Subject Categories:Prior Versions
Available on InterRegs.NET

Our online subscription service, offering immediate access to our extensive library of global vehicle regulations, standards and legislation. A fully searchable, accurate, user-friendly resource for consolidated regulations that are updated quickly and frequently.

Tell me more | Already a subscriber

Available on SelectRegs.com

Our fast and easy means of purchasing up-to-date global vehicle and component standards and regulations on a pay-as-you-go basis. Pay securely by credit card and your documents are delivered directly and immediately to your computer as PDF files.

Tell me more | Go straight to site

Keywords:

motorcycle, test, approval, regulation, type, exhaust, sound, annex, system, surface, speed, engine, noise, requirements, paragraph, number, amendments, measured, series, motorcycles, level, microphone, maximum, track, measurements, silencing, voids, fitted, granted, area, figure, absorption, measurement, content, order, texture, made, tests, measuring, date, material, ece, cores, line, parties, components, position, mark, method, means

Text Extract:

All InterRegs documents are formatted as PDF files and contain the full text, tables, diagrams and illustrations of the original as issued by the national government authority. We do not re-word, summarise, cut or interpret the regulatory documents. They are consolidated, published in English, and updated on a regular basis. The following text extract indicates the scope of the document, but does not represent the actual PDF content.

E/ECE/324 )
E/ECE/TRANS/505 ) Rev.1/Add.40/Rev.1/Corr.1
October 3, 2008
STATUS OF UNITED NATIONS REGULATION
ECE 41-03
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 to the 03 series of amendments
Dated: 07.08.08

REGULATION No. 41
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF MOTORCYCLES
WITH REGARD TO NOISE
CONTENTS
1.
Scope
2.
Definitions
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 Definitely Discontinued
11.
Names and Addresses of Technical Services Responsible for Conducting Approval Tests,
and of Administrative Departments
12.
Transitional Provisions
ANNEXES
Annex 1 – Communication concerning the approval or extension or refusal or withdrawal of approval of
production definitely discontinued of a motorcycle type with regard to noise emitted by
motorcycles pursuant to Regulation No. 41.
Annex 2 – Arrangements of approval marks.
Annex 3 – Methods and instruments for measuring the noise made by motorcycles.
Annex 4 – Test track specifications
Annex 5 – Exhaust system (silencer).
Annex 6 – Maximum limits of sound level (new motorcycles).

2.5. "Component of an exhaust 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 must be treated as components having the same importance as the exhaust
system.
3. APPLICATION FOR APPROVAL
3.1. The application for approval of a motorcycle type with regard to noise made by motorcycles
shall be submitted by its manufacturer or by his duly accredited representative.
3.2. It shall be accompanied by the under-mentioned documents in triplicate and the following
particulars:
3.2.1. a description of the motorcycle type with regard to the items mentioned in Paragraph 2.2.
above. The numbers and/or symbols identifying the engine type and the motorcycle type
shall be specified;
3.2.2. a list of the components, duly identified, constituting the exhaust or silencing system;
3.2.3. a drawing of the assembled exhaust or silencing system and an indication of its position on
the motorcycle;
3.2.4. detailed drawings of each component to enable it to be easily located and identified, and a
specification of the materials used.
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.

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:
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)
the manufacturer's name
(b) the value in dB(A) recorded during the stationary test required by Paragraph 6.2.1.1.
(c)
the engine speed at ¾ S if S does not exceed 5000 min , or at ½ S if S exceeds
5000 min

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 must 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. Production will be
regarded as conforming to the provisions of this Regulation if the sound level measured
using the method described in Annex 3, does not exceed by more than 3 dB(A) the value
measured at the time of type-approval, nor by more than 1 dB(A) the limits laid down in
Annex 6 of this Regulation.
9. PENALTIES FOR NON-CONFORMITY OF PRODUCTION
9.1. The approval granted in respect of a motorcycle type pursuant to this Regulation may be
withdrawn if the requirements laid down in Paragraph 8.1. above are not complied with, or if
the motorcycle has failed to pass the tests provided for in Paragraph 8.2. above.
9.2. If a Party to the Agreement which applies this Regulation withdraws an approval it has
previously granted, it shall forthwith so notify the other Contracting Parties applying this
Regulation, by means of a communication form conforming to the model in Annex 1 to this
Regulation.
10. PRODUCTION DEFINITELY DISCONTINUED
If the holder of the approval completely ceases to manufacture a type of a motorcycle
approved in accordance with this Regulation, he shall so inform the authority which granted
the approval. Upon receiving the relevant communication, that authority shall inform thereof
the other Parties to the Agreement applying this Regulation by means of a communication
form conforming to the model in Annex 1 to this Regulation.
11. NAMES AND ADDRESSES OF TECHNICAL SERVICES RESPONSIBLE FOR
CONDUCTING APPROVAL TESTS, AND OF ADMINISTRATIVE DEPARTMENTS
The Parties to the 1958 Agreement applying this Regulation shall communicate to the
United Nations Secretariat the names and addresses of the technical services responsible
for conducting approval tests and of the administrative departments which grant approval
and to which forms certifying approval or extension or refusal or withdrawal of approval,
issued in other countries, are to be sent.

ANNEX 1
COMMUNICATION
(Maximum format: A 4 (210 x 297 mm) )
issued by:
Name of administration:
.............................................
.............................................
.............................................
concerning:
APPROVAL GRANTED
APPROVAL EXTENDED
APPROVAL REFUSED
APPROVAL WITHDRAWN
PRODUCTION DEFINITELY DISCONTINUED
of a motorcycle type with regard to noise emitted by motorcycles pursuant to Regulation No. 41
Approval No...................................................
Extension No. ................................
1.
Trade name or mark of the motorcycle......................................................................................
2.
Motorcycle type..........................................................................................................................
3.
Manufacturer's name and address ............................................................................................
4.
If applicable, name and address of manufacturer's representative ...........................................
...................................................................................................................................................
...................................................................................................................................................
5.
Kind of engine
........................................................................................................................
6.
Cycles: two-stroke or four-stroke (if applicable).........................................................................
7.
Cylinder capacity........................................................................................................................
8.
Engine power (state how measured) .........................................................................................
9.
Speed at which maximum power is developed (rpm)................................................................

29. The following documents, bearing the approval number shown above, are annexed to this
communication:
................... 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 (measuring conditions and method for testing of the
vehicle during component type approval).
1.1. Limits: see Annex 6
1.2. Measuring Instruments
1.2.1. Acoustic Measurements
The apparatus used for measuring the sound level shall be a precision sound-level meter of
the type described in International Electrotechnical Commission (IEC) Publication 179
"Precision sound-level meters", second edition.
Measurements shall be carried out using the 'fast' response of the sound-level meter and
the 'A' weighting also described in that publication.
At the beginning and end of each series of measurements the sound-level meter shall be
calibrated in accordance with the manufacturer's instructions, using an appropriate sound
source (e.g. pistonphone).
1.2.2. Speed Measurements
Engine speed and motorcycle speed on the test track shall be determined to within ± 3%.
1.3. Conditions of Measurement
1.3.1. Condition of the Motorcycle
During the measurements the motorcycle shall be in running order (including coolant, oils,
fuel, tools, spare wheel and rider).
Before the measurements are made the motorcycle shall be brought to the normal operating
temperature. If the motorcycle is fitted with fans with an automatic actuating mechanism,
this system shall not be interfered with during the sound measurements. For motorcycles
having more than one driven wheel, only the drive provided for normal road operation may
be used. Where a motorcycle is fitted with a sidecar, this must be removed for the purposes
of the test.

1.4. Method of Measurement
1.4.1. Nature and Number of Measurements
The maximum sound level expressed in A-weighted decibels (dB(A)) shall be measured as
the motorcycle travels between Lines AA' and BB' (Figure 1). The measurement will be
invalid if an abnormal discrepancy between the peak value and the general sound level is
recorded. At least two measurements shall be taken on each side of the motorcycle.
1.4.2. Positioning of the Microphone
The microphone shall be located 7,5 m ± 0,2 m from the reference Line CC
(see Appendix - Figure 1) of the track and 1,2 m ± 0,1 m above ground level.
1.4.3. Conditions of Operation
The motorcycle shall approach Line AA' at an initial steady speed as specified in 1.4.3.1 and
1.4.3.2. When the front of the motorcycle reaches Line AA' the throttle shall be fully opened
as quickly as practically possible and kept in that position until the rear of the motorcycle
reaches Line BB'; the throttle must then be returned as quickly as possible to the idle
position.
For all measurements the motorcycle must be ridden in a straight line over the acceleration
section keeping the longitudinal median plane of the motorcycle as close as possible to
Line CC,.
1.4.3.1. Motorcycles with Non-automatic Gearboxes
1.4.3.1.1. Approach Speed
The motorcycle shall approach Line AA' at a steady speed of:
(i)
50 km/h
or
(ii)
speed corresponding to an engine speed equal to 75% of the speed specified under
Item 9 of Annex 1.
The lower of these speeds shall be selected.
1.4.3.1.2. Selection of Gear Ratio
1.4.3.1.2.1. Motorcycles fitted with a gearbox having a maximum of four ratios, whatever the cylinder
capacity of their engines, shall be tested only in second gear.
1.4.3.1.2.2. Motorcycles fitted with engines having a cylinder capacity not exceeding 175 cm and a
gearbox with five ratio or more shall be tested only in third gear.
1.4.3.1.2.3. Motorcycles fitted with engines having a cylinder capacity of more than 175 cm and a
gearbox with five ratios or more shall be tested once in second gear and once in third
gear. The result used must be the average of the two tests.

1.5. Results
1.5.1. The communication referred to in Annex 1 shall indicate any circumstances and influence
affecting the results of the measurements.
1.5.2. Readings taken shall be rounded off to the nearest decibel.
If the figure following the decimal point is between 0 and 4, the total is rounded down and if
between 5 and 9, it is rounded up.
Only those measurements whose variation in two consecutive tests on the same side of the
motorcycle is less than or equal to 2 dB(A) may be used for the purpose of issuing the
communication referred to in Annex 1.
1.5.3. To take account of inaccuracies in the measurements, the result of each measurement shall
be arrived at by deducting 1 dB(A) from the value obtained in accordance with 1.5.2.
1.5.4. If the average of the four results of the measurements does not exceed the maximum
permissible level for the category to which the motorcycle being tested belongs, the limit laid
down in Paragraph 1.1. will be deemed as being complied with. This average value will
constitute the result of the test.
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 1.2.1. shall be used.
2.3. Conditions of Measurement
2.3.1. Condition of the Motorcycle
Before the measurements are made the motorcycle engine shall be brought to the normal
operating temperature. If the motorcycle is fitted with fans with an automatic actuating
mechanism, this system shall not be interfered with during the sound measurements.
During the measurements the gearbox shall be in neutral gear. If it is impossible to
disconnect the transmission, the driving wheel of the motorcycle shall be allowed to rotate
freely, for example by placing the vehicle on its centre stand.

2.4.3. Operating Conditions
2.5. Results
The engine speed shall be held steady at one of the following values:
½ S if S is more than 5,000 rpm
¾ S if S is not more than 5,000 rpm
where S is the speed specified under Item 9 of Annex 1.
When a constant engine speed is reached, the throttle shall be returned swiftly to the idle
position. The sound level shall be measured during an operating cycle consisting of a brief
period of constant engine speed and throughout the deceleration period, the maximum
sound-level meter reading being taken as the test value.
2.5.1. The Communication referred to in Annex 1 shall indicate all relevant data and particularly
used in measuring the noise of the stationary motorcycle.
2.5.2. Values, rounded off to the nearest decibel, shall be read off the measuring instrument.
If the figure following the decimal point is between 0 and 4, the total is rounded down and if
between 5 and 9, it is rounded up.
Only those measurements which vary by no more than 2 dB(A) in three consecutive tests
will be used.
2.5.3. The highest of the three measurements will constitute the test result.

ANNEX 4
SPECIFICATIONS FOR THE TEST SITE
1. INTRODUCTION
This annex describes the specifications relating to the physical characteristics and the laying
of the test track. These specifications, based on a special standard, describe the required
physical characteristics as well as the test methods for these characteristics.
2. REQUIRED CHARACTERISTICS OF THE SURFACE
A surface is considered to conform to this standard provided that the texture and voids
content or sound absorption coefficient have been measured and found to fulfil (all) the
requirements of Paragraphs 2.1. to 2.4. below and provided that the design requirements
(Paragraph 3.2.) have been met.
2.1. Residual Voids Content
The residual voids content V , of the test track paving mixture shall not exceed 8%. For the
measurement procedure, see Paragraph 4.1.
2.2. Sound Absorption Coefficient
If the surface fails to conform to the residual voids content requirement, the surface is
acceptable only if its sound absorption coefficient, α, ≤ 0.10. For the measurement
procedure, see Paragraph 4.2. The requirement of Paragraphs 2.1. and 2.2. is met also if
only sound absorption has been measured and found to be α ≤ 0.10.
Note: The most relevant characteristic is the sound absorption, although the residual voids
content is more familiar among road constructors. However, sound absorption needs to be
measured only if the surface fails to conform to the voids requirement. This is because the
latter is connected with relatively large uncertainties in terms of both measurements and
relevance and some surfaces may therefore be rejected erroneously when the voids
measurement only is used as a basis.
2.3. Texture Depth
The texture depth (TD) measured according to the volumetric method (see Paragraph 4.3.
below) shall be:
TD ≥ 0.4 mm

Figure 1
Minimum Requirements for Test Surface Area
The Shaded Part is called "Test Area"
3.2.
Design and Preparation of the Surface
3.2.1.
Basic Design Requirements
The test surface shall meet four design requirements:
3.2.1.1.
It shall be a dense asphaltic concrete.
3.2.1.2.
The maximum chipping size shall be 8 mm (tolerances allow from 6.3 to 10 mm).
3.2.1.3.
The thickness of the wearing course shall be ≥ 30 mm.
3.2.1.4.
The binder shall be a straight penetration grade bitumen without modification.

In addition to the above, the following recommendations are given:





The sand fraction (0.063 mm < square mesh sieve size < 2 mm) shall include no
more than 55% natural sand and at least 45% crushed sand;
The base and sub-base shall ensure a good stability and evenness, according to best
road construction practice,
The chippings shall be crushed (100% crushed faces) and of a material with a high
resistance to crushing,
The chippings used in the mix shall be washed,
No extra chippings shall be added onto the surface,
− The binder hardness expressed as PEN value shall be 40-60, 60-80 or even 80-100
depending on the climatic conditions of the country. The rule is that as hard a binder
as possible shall be used, provided this is consistent with common practice;

The temperature of the mix before rolling shall be chosen so as to achieve by
subsequent rolling the required voids content. In order to increase the probability of
satisfying the specifications of Paragraphs 2.1 to 2.4 above, the compactness shall be
studied not only by an appropriate choice of mixing temperature, but also by an
appropriate number of passings and by the choice of compacting vehicle.
Table 1
Design Guidelines
Target values
By total
mass
of mix
By mass
of the
aggregate
Tolerances
Mass of stones, Square Mesh Sieve (SM) > 2 mm
47.6%
50.5%
± 5
Mass of sand 0,063 < SM < 2 mm
38.0%
40.2%
± 5
Mass of filler SM < 0,063 mm
8.8%
9.3%
± 2
Mass of binder (bitumen)
5.8%
N.A.
± 0,5
Maximum chipping size
8 mm
6.3-10
Binder hardness
(see Paragraph 3.2.2. (f))
Polished stone value (PSV)
> 50
Compactness, relative to Marshall compactness
98%

5. STABILITY IN TIME AND MAINTENANCE
5.1. Age Influence
In common with any other surfaces, it is expected that the tyre/road noise level measured
on the test surface may increase slightly during the first 6-12 months after construction.
The surface will achieve its required characteristics not earlier than four weeks after
construction. The influence of age on the noise from trucks is generally less than that from
cars.
The stability over time is determined mainly by the polishing and compaction by vehicles
driving on the surface. It shall be periodically checked as stated in Paragraph 2.5.
5.2. Maintenance of the Surface
Loose debris or dust which could significantly reduce the effective texture depth must be
removed from the surface. In countries with winter climates, salt is sometimes used for
de-icing. Salt may alter the surface temporarily or even permanently in such a way as to
increase noise and is therefore not recommended.
5.3. Repaving the Test Area
If it is necessary to repave the test track, it is usually unnecessary to repave more than the
test strip (of 3 m width in Figure 1) where vehicles are driving, provided the test area outside
the strip met the requirement of residual voids content or sound absorption when it was
measured.
6. DOCUMENTATION OF THE TEST SURFACE AND OF TESTS PERFORMED ON IT
6.1. Documentation of the Test Surface
The following data shall be given in a document describing the test surface:
6.1.1. The location of the test track.
6.1.2. Type of binder, binder hardness, type of aggregate, maximum theoretical density of the
concrete (D ), thickness of the wearing course and grading curve determined from cores
from the test track.
6.1.3. Method of compaction (e.g. type of roller, roller mass, number of passes);
6.1.4. Temperature of the mix, temperature of the ambient air and wind speed during laying of the
surface.
6.1.5. Date when the surface was laid and contractor.

ANNEX 5
EXHAUST SYSTEM (SILENCER)
1. Fibrous absorbent material must be asbestos-free and may be used in the construction of
silencers only if suitable devices ensure that the fibrous material is kept in place for the
whole time that the silencer is being used and it meets the requirements of any one of
Paragraphs 1.1., 1.2. and 1.3.
1.1. After removal of the fibrous material, the sound level must comply with the requirements of
Annex 3 and the sound level limits of Annex 4.
1.2. The fibrous absorbent material may not be placed in those parts of the silencer through
which the exhaust gases pass and must comply with the following requirements:
1.2.1. The material must be heated at a temperature of 650 ± 5° C for four hours in a furnace
without reduction in every length, diameter or bulk density of the fibre.
1.2.2. After heating at 650 ± 5° C for one hour in a furnace, at least 98% of the material must be
retained in a sieve of nominal aperture size 250 µm complying with
ISO Standard 3310/1 : 1990 when tested in accordance with ISO Standard 2599 : 2000.
1.2.3. The loss in weight of the material must not exceed 10.5% after soaking for 24 hours at
90 ± 5° C in a synthetic condensate of the following composition:
1 N hydrobromic acid (HBr): 10 ml
1 N sulphuric acid (H SO ): 10 ml
Distilled water to make up to 1,000 ml.
Note: The material must be washed in distilled water and dried for one hour at 105° C
before weighing.
1.3. Before the system is tested in accordance with Annex 3, it must be put into a normal state
for road use by one of the following condition methods:
1.3.1. Conditioning By Continuous Road Operation
1.3.1.1. According to the classes of motorcycles, the minimum distances to be completed during
conditioning are:
Class of motorcycle according to cylinder capacity in cm
Distance (km)
Class I ≤ 80
4 000
Class II > 80 ≤ 175
6 000
Class III > 175
8 000
1.3.1.2. 50 ± 10% of this conditioning cycle consists of town driving and the remainder of
long-distance runs at high speed; the continuous road cycle may be replaced by a
corresponding test-track programme.
1.3.1.3. The two speed regimes must be alternated at least six times.

1.3.3.4. Each test-bench cycle consists of six phases. The engine conditions for and the duration of
each phase are:
Phase
Conditions
Engines ≤ 175 cm
(minutes)
Duration of phase
Engines > 175 cm
(minutes)
1 Idling 6 6
2 25% load at 75% S 40 50
3 50% load at 75% S 40 50
4 100% load at 75% S 30 10
5 50% load at 100% S 12 12
6 25% load at 100% S 22 22
Total time 2.5 hours 2.5 hours
1.3.3.5 During this conditioning procedure, at the request of the manufacturer, the engine and the
silencer may be cooled in order that the temperature recorded at a point not more than
100 mm from exhaust gas outlet does not exceed that measured when the motorcycle is
running at 110 km/h or 75% S in top gear. The engine and/or motorcycle speeds are
determined to within ± 3%.

ANNEX 6
MAXIMUM LIMITS OF SOUND LEVEL (NEW MOTORCYCLES)
Class of Motorcycle Engine Cylinder Capacity (cc) Values expressed in dB(A)
First category
Second category
Third category
cc ≤ 80 cm
80 cm < cc ≤ 175 cm
cc > 175 cm
75
77
80
Noise - Motorcycles.