UN Regulation No. 41 - Uniform provisions concerning the approval of motor cycles with regard to noise [2025/2412]
Date: 2025-12-12
Institutions: United Nations Economic Commission for Europe
Subjects: approval, noise level, noise pollution, safety standard, technical specification, technical standard, two-wheeled vehicle




L_202502412EN.000101.fmx.xml












Official Journal of the European Union


EN
L series













2025/2412


12.12.2025





Only the original UN/ECE texts have legal effect under international public law. The status and date of entry into force of this Regulation should be checked in the latest version of the UN/ECE status document TRANS/WP.29/343, available at: https://unece.org/status-1958-agreement-and-annexed-regulations



UN Regulation No. 41 - Uniform provisions concerning the approval of motor cycles with regard to noise [2025/2412]

Incorporating all valid text up to:
06 series of amendments – Date of entry into force: 11 January 2026
      
CONTENTS
Regulation







1.

Scope











2.

Definitions, terms and symbols











3.

Application for approval











4.

Markings











5.

Approval











6.

Specifications











7.

Modification and extension of the approval of the motor cycle 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 the Type Approval Authorities











12.

Transitional provisions




Annexes







1

Communication











2

Arrangements of approval marks











3

Methods and instruments for measuring noise made by motor cycles











4

Test track layout











5

Exhaust or silencing systems containing fibrous material











6

Maximum limits of sound levels











7

Additional Sound Emission Provisions (ASEP)











8

Statement of compliance with the Additional Sound Emission Provisions (ASEP)




1.   Scope
This Regulation applies to vehicles of category L3
             (1) with regard to noise.
The specifications in this Regulation are intended to reproduce the sound levels which are generated by vehicles during normal driving in urban traffic.
This Regulation provides, as well, Real Driving Additional Sound Emission Provisions (RD-ASEP) for vehicles of category L3 referring to typical on road driving conditions including high accelerations and engine loads for urban and suburban traffic, except for highways situations.
2.   Definitions, terms and symbols
For the purpose of this Regulation








2.1.


"Approval of a motorcycle" means the approval of a motorcycle type with regard to noise;












2.2.


"Type of motorcycle as regards its sound level" means motorcycles which do not differ in such essential respects as the following:












2.2.1.


The type of engine (two-stroke or four-stroke, reciprocating piston engine or rotary-piston engine, number and capacity of cylinders or rotors, number and type of carburettors or injection systems, arrangement of valves, rated maximum net power and corresponding engine speed). For rotary-piston engines the cubic capacity should be taken to be double of the volume of the chamber;












2.2.2.


Transmission system, in particular the number and ratios of the gears and the overall gear ratio taking into account the rear wheel circumference.












2.2.3.


Configurations and arrangements of exhaust or silencing systems.












2.3.


"Exhaust or silencing system" means a complete set of components necessary to limit the noise caused by a motorcycle engine and its exhaust.












2.3.1.


"Original exhaust or silencing system" means a system of a type fitted to the vehicle at the time of type approval or extension of type approval. It may also be the vehicle manufacturer's replacement part.












2.3.2.


"Non-Original Replacement Exhaust or Silencing System (NORESS)" means a system of a type other than that fitted to the vehicle at the time of type approval or extension of type approval.












2.4.


"Exhaust or silencing systems of differing configurations" means systems which are fundamentally different in one of the following ways:












2.4.1.


Systems comprising components bearing different factory or trademarks;












2.4.2.


Systems comprising any component made of materials of different characteristics or comprising components which are of a different shape or size;












2.4.3.


Systems in which the operating principles of at least one component are different;












2.4.4.


Systems comprising components in different combinations.












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)


Full electrical equipment including the lighting and signalling devices supplied by the manufacturer;










(b)


All instruments and fittings required by any legislation in respect of which a measurement of the vehicle dry mass is being made;










(c)


Full complement of liquids to ensure the correct functioning of every part of the vehicle and the fuel tank filled at least to 90 percent of the capacity specified by the manufacturer;










(d)


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
n 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)













2.9.


"Power-to-mass ratio index" means the ratio of the rated maximum net power of a vehicle to its mass. It is defined as:

PMR = (P
n / (m
kerb + 75)) * 1000
Where m
kerb is the numerical value of the kerb mass as defined in paragraph 2.6. above, expressed in kilograms.
The symbol PMR denotes the power-to-mass ratio index.












2.10.


"Maximum speed" means the maximum vehicle speed as defined in ISO 7117:1995.
The symbol v
max denotes the maximum speed.












2.11.


"Locked gear" means the control of the transmission such that the transmission gear ratio cannot change during a test.












2.12.


"Engine" means the power source of the vehicle without detachable accessories.












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




awot



m/s2



calculated acceleration


Annex 3 – 1.4.2.




awot,ref



m/s2



prescribed reference acceleration


Annex 3 – 1.3.3.3.1.2.




aurban



m/s2



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.




kp



–


partial power factor


Annex 3 – 1.4.4.




L


dB(A)


sound pressure level


Annex 3 – 1.4.1.




L wot(i)



dB(A)


L at wot condition


Annex 3 – 1.4.6.




LASEP



dB(A)


L at RD-ASEP additional operating conditions


Annex 7 – 3.3.3.2.




lPA



m


pre-acceleration length


Annex 3 – 1.3.3.1.1.




mkerb



kg


kerb mass of the vehicle


2.6.




mt



kg


test mass of the vehicle


Annex 3 – 1.3.2.2.




n


min-1



engine speed


 




nAA’,min



min-1



Minimum engine speed of the RD-ASEP control range at line AA’


Annex 7 – 2.5




nBB’,max



min-1



Maximum engine speed of RD-ASEP control range at line BB’


Annex 7 – 2.5




nPP’



min-1



engine speed at PP’


Annex 7 – 2.6.




nidle



min-1



engine speed at idle


–




nwot(i)



min-1



nPP' measured at Lwot(i) detection


Annex 7 – 2.6.




nadj



min-1



adjustment factor for low PMR vehicles with high S


Annex 7 – 2.6.




PP'


–


virtual line on the test track


Annex 4 – Figure 1




PMR


–


power-to-mass ratio index


2.9.




Pn



kW


rated maximum net power


2.7.




S


min-1



rated engine speed


2.8.




V


km/h


measured vehicle speed


–




vmax



km/h


maximum speed


2.10.




vtest



km/h


prescribed test speed


Annex 3 – 1.3.3.1.1.




The following indices are used for measured engine speeds "n" and vehicle speeds "v" to indicate the location or rather time of the measurement:






(a)


AA' denoting that the measurement corresponds to the point in time when the front of the vehicle passes the line AA' (see Annex 4 – Figure 1); or










(b)


PP' denoting that the measurement corresponds to the point in time when the front of the vehicle passes the line PP' (see Annex 4 – Figure 1); or










(c)


BB' denoting that the measurement corresponds to the point in time when the rear of the vehicle passes the line BB' (see Annex 4 – Figure 1).




The following indices are used for calculated full throttle accelerations a
wot and measured sound pressure levels L to indicate the gear used for the test:






(a)


"(i)" denoting, in the case of a two-gear test, the lower gear (i.e. the gear with the higher gear transmission ratio) and otherwise referring to the single test gear or gear selector position used; or










(b)


"(i + 1)" denoting, in the case of a two-gear test, the higher gear (i.e. the gear with the lower gear transmission ratio).




Measured sound pressure levels L also carry an index indicating the type of the respective test:






(a)


"Wot" denoting a full throttle acceleration test (see paragraph 1.3.3.1.1. of Annex 3); or










(b)


"CRS" denoting a constant speed test (see paragraph 1.3.3.3.2. of Annex 3); or










(c)


"Urban" denoting a weighted combination of a constant speed test and a full throttle acceleration test (see paragraph 1.4.6.2. of Annex 3).




The index "j" referring to the number of the test run can be used in addition to the indices mentioned above.




3.   Application for approval








3.1.


The application for approval of a motor cycle type with regard to its sound emissions 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 motor cycle type with regard to the items mentioned in paragraph 2.2. above. The numbers and/or symbols identifying the engine type and the motor cycle 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 motor cycle;












3.2.4.


Drawings of each component to enable it to be easily located and identified, and a specification of the materials used;












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.


Respective documents mentioned in paragraph 3.2 above shall be prepared for each exhaust or silencing system configuration, if multiple configurations are applicable to the motorcycle type to be approved.












3.4.


At the request of the technical service responsible for conducting approval tests in agreement with the type approval authorities, the motorcycle manufacturer shall, in addition, submit a sample of the exhaust or silencing system(s).












3.5.


All motorcycle(s) representative of the same type with all possible exhaust or silencing system configurations to be approved shall be submitted to the technical service responsible for conducting approval tests in agreement with the type approval authorities.












3.6.


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)


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;










(b)


The type of measuring equipment including the windscreen;










(c)


The A-weighted sound pressure level typical of the background noise;










(d)


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, awot ref, aurban, vehicle length;










(e)


The transmission gears or gear ratios used during the test;










(f)


For tests according to Annex 3 of this Regulation and for the reference points tests of Annex 7 paragraph 3.2. 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;










(g)


For tests according to Annex 3 of this Regulation and according to the reference points test of Annex 7 paragraph 3.2. the vehicle speed and engine speed at PP' and at the end of the acceleration per valid measurement;










(h)


For tests according to Annex 7, paragraph 3.3. the vehicle speed and the engine speed at lines AA’, PP’ and BB’;










(i)


For tests according to Annex 7, paragraph 3.3. the approach condition to line AA’ (acceleration, deceleration or constant speed) and the prescribed throttle control position (in % of throttle control opening) between lines AA’ and BB’;







Note:



This is a description of the prescribed throttle control operation. The actual throttle control operation during a test run will not be recorded but assessed by observation only;














(j)


The method used for calculation of the acceleration;










(k)


The intermediate measurement results awot(i), awot(i + 1), Lwot(i), Lwot(i + 1), Lcrs(i) and Lcrs(i + 1), if applicable;










(l)


The weighting factors k and kp and the final measurement results Lwot, Lcrs, Lurban and LASEP;










(m)


The auxiliary equipment of the vehicle, where appropriate, and its operating conditions;










(n)


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










(o)


All relevant information necessary to obtain the different sound emission levels.








4.   Markings








4.1.


The components of the exhaust or silencing system shall bear at least the following identifications:












4.1.1.


The trade name or mark of the manufacturer of the exhaust or silencing system and of its components;












4.1.2.


The trade description given by the manufacturer;












4.1.3.


The identifying part numbers; and












4.1.4.


For all original silencers, the "E" mark followed by the identification of the country which granted the component type approval. (3)













4.1.5.


Any packing of original replacement exhaust or silencing systems shall be marked legibly with the words "original part" and the make and type references integrated together with the "E" mark and also the reference of the country of origin.












4.1.6.


Such markings shall be indelible, clearly legible and also visible, in the position at which it is to be fitted to the vehicle.




5.   Approval








5.1.


If the motor cycle type submitted for approval pursuant to this Regulation meets the requirements of paragraphs 6. and 7. below, approval of that motor cycle type shall be granted.












5.2.1.


An approval number shall be assigned to each type approved. Its first two digits indicate the series of amendments incorporating the most recent major technical amendments made to the Regulation at the time of issue of the approval. The same Contracting Party may not assign the same number to another motorcycle type.












5.2.2.


Multiple exhaust or silencing system configurations shall be explicitly listed under the same approval of a type of motorcycle with their respective test results.












5.3.


Notice of approval or of refusal of approval of a motorcycle type pursuant to this Regulation shall be communicated to the Parties to the Agreement which apply this Regulation, by means of a form conforming to the model in Annex 1 to this Regulation and of drawings of the exhaust or silencing system, supplied by the applicant for approval in a format not exceeding A4 (210 × 297 mm) or folded to that format and on an appropriate scale.












5.4.


The respective information for multiple exhaust or silencing system configurations mentioned in paragraph 5.2.2. above shall be provided for in Annex 1 to this Regulation.












5.5.


There shall be affixed, conspicuously and in a readily accessible place specified on the approval form, to every motor cycle conforming to a motor cycle type approved under this Regulation an international approval mark consisting of:












5.5.1.


A circle surrounding the letter "E" followed by the distinguishing number of the country which has granted approval3; and












5.5.2.


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 5.5.1.












5.6.


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 5.5.1. 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 5.5.1.












5.7.


The approval mark shall be clearly legible and be indelible.












5.8.


The approval mark shall be placed close to or on the motor cycle data plate affixed by the manufacturer.












5.9.


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 motor cycle in an easily accessible but not necessarily immediately visible location:






(a)


The manufacturer's name;










(b)


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 motor cycles of category L3 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). (4)

















6.2.


Specifications regarding sound levels












6.2.1.


The sound emissions of the motor cycle type submitted for approval shall be measured by the two methods described in Annex 3 to this Regulation (motor cycle in motion and motor cycle when stationary) (5); in the case of a motor cycle where an internal combustion engine does not operate when the motor cycle is stationary, the emitted noise shall only be measured in motion.












6.2.2.


The test results obtained in accordance with the provisions of paragraph 6.2.1. above shall be entered in the test report and on a form conforming to the model in Annex 1 to this Regulation.












6.2.3.


The test results for the motor cycle in motion obtained in accordance with paragraph 1. of Annex 3 to this Regulation and mathematically rounded to the nearest integer shall not exceed the limits prescribed (for new motor cycles and new silencing systems) in Annex 6 to this Regulation for the category to which the motor cycle belongs. In any case, L
wot shall not exceed the limit value for L
urban by more than 5 dB.












6.3.


Additional sound emission provisions












6.3.1.


The motorcycle manufacturer shall not use any device, procedure or software which would modify any noise related functional parameters of the vehicle for the purpose of passing the tests within this Regulation and which would result in increased noise emissions during typical on-road operation in the RD-ASEP control range of Annex 7 paragraph 2.5, compared to during testing according to the provisions of this regulation.












6.3.2.


The vehicle type to be approved shall meet the requirements of Annex 7 to this Regulation. If the motorcycle has user selectable software programs or modes which affect the sound emission of the vehicle, all these modes shall be in compliance with the requirements in Annex 7.












6.3.3.


In the application for type approval or for modification or extension of a type approval the manufacturer shall provide a statement in accordance with Annex 8 that the vehicle type to be approved complies with the requirements of paragraph 6.3.1. of this Regulation.












6.3.4.


The test results obtained in accordance with the provisions of paragraph 6.3.2. above shall be entered in the test report and on a form conforming to the model in Annex 1 to this Regulation.












6.4.


Additional specifications regarding exhaust or silencing systems filled with fibrous material












6.4.1.


If the exhaust or silencing system of the motor cycle contains fibrous materials the requirements of Annex 5 shall apply. If the intake of the engine is fitted with an air filter and/or an intake-noise absorber which is (are) necessary in order to ensure compliance with the permissible sound level, the filter and/or absorber shall be considered to be part of the silencing system, and the requirements of Annex 5 shall also apply to them.












6.5.


Additional prescriptions related to tamperability 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 motor cycle type or of the type of exhaust or silencing system(s)








7.1.


Every modification of the motor cycle type or of the exhaust or silencing system shall be notified to the Type Approval Authority which approved the motor cycle 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 motor cycle 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 motor cycle manufactured shall conform to a type of motor cycle 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 (Lurban and Lwot) 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 3.0 dB(A) the values measured and processed at the time of type approval. Furthermore, Lurban shall not exceed by more than 1.0 dB(A) the limit laid down in Annex 6 of this Regulation, and Lwot, in connection with 6.2.3., shall not exceed the limit value for Lurban by more than 6.0 dB(A).












8.3.


For conformity of production, the manufacturer shall make a renewed declaration that the type still fulfils the requirements of paragraph 6.3.1. of this Regulation. The measured sound levels according to Annex 7 shall not exceed by more than 1.0 dB(A) the limits given in paragraph 2.6. of Annex 7. As a minimum, tests in the operating conditions for the reference points according to paragraph 3.2. of Annex 7 shall be performed.












8.4.


If due to substantially different barometric pressure, humidity, temperature or rider mass, the reference acceleration awot,ref defined in paragraph 1.3.3.3.1.2. of Annex 3 cannot be reached with the same gear in conformity of production as in type approval tests, the gear determined according to the requirement of paragraph 1.3.3.3.1.3.1. of Annex 3 during type-approval shall prevail and the conformity of production tests can be performed using an acceleration different from awot,ref.





9.   Penalties for non-conformity of production








9.1.


The approval granted in respect of a motor cycle type pursuant to this Regulation may be withdrawn if the requirements laid down in paragraph 8. above are not met.












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 motor cycle approved in accordance with this Regulation, he shall 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 the Type Approval Authorities
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 Type Approval Authorities 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.
12.   Transitional provisions








12.1.


As from the official date of entry into force of the 06 series of amendments, no Contracting Party applying this Regulation shall refuse to grant or refuse to accept type approvals under this Regulation as amended by the 06 series of amendments.












12.2.


As from 1 January 2029, Contracting Parties applying this Regulation shall not be obliged to accept type approvals to the preceding series of amendments, first issued after 1 January 2029.












12.3.


Until 1 January 2030, Contracting Parties applying this Regulation shall accept type approvals to the preceding series of amendments, first issued before 1 January 2029.












12.4.


As from 1 January 2030, Contracting Parties applying this Regulation shall not be obliged to accept type approvals issued to the preceding series of amendments to this Regulation.












12.5.


Notwithstanding the transitional provisions above, Contracting Parties who start to apply this Regulation after the date of entry into force of the most recent series of amendments are not obliged to accept type approvals which were granted in accordance with any of the preceding series of amendments to this Regulation / are only obliged to accept type approval granted in accordance with the 06 series of amendments.












12.6.


Notwithstanding paragraph 12.4, Contracting Parties applying this Regulation shall continue to accept type approvals issued according to the preceding series of amendments to this Regulation, for the vehicles/vehicle systems which are not affected by the changes introduced by the 06 series of amendments.












12.7.


Contracting Parties applying this Regulation may grant type approvals according to any preceding series of amendments to this Regulation.












12.8.


Contracting Parties applying this Regulation shall continue to grant extensions of existing approvals to any preceding series of amendments to this Regulation.












12.9.


From 10 January 2025, ISO 10844:2021 shall be accepted for all approvals granted under this Regulation. Until 10 January 2030, ISO 10844:2014 shall be accepted for all approvals granted under this Regulation.






(1)  As defined in the Consolidated Resolution on the Construction of Vehicles (R.E.3.), document ECE/TRANS/WP.29/78/Rev.7, para. 2 - https://unece.org/transport/vehicle-regulations/wp29/resolutions.

(2)  If the rated maximum net power is reached at several engine speeds, S is used in this Regulation as the highest engine speed at which the rated maximum net power is reached.

(3)  The distinguishing numbers of the Contracting Parties to the 1958 Agreement are reproduced in Annex 3 to the Consolidated Resolution on the Construction of Vehicles (R.E.3), document ECE/TRANS/WP.29/78/Rev. 7, Annex 3- https://unece.org/transport/vehicle-regulations/wp29/resolutions.

(4)  The establishment of an electronic type approval database is expected to make the provision of in-use compliance reference data on the motor cycle superfluous.

(5)  A test is made on a stationary motor cycle in order to provide a reference value for administrations which use this method to check motor cycles in use.




ANNEX 1

Communication

(Maximum format: A4 (210 × 297 mm)












 (1)


issued by:


Name of administration
…
…
…













concerning (2):


Approval granted
Approval extended
Approval refused
Approval withdrawn
Production definitely discontinued




of a motor cycle type with regard to noise emitted by motor cycles pursuant to Regulation No. 41
Approval No.: … Extension No.: …








1.


Trade name or mark of the motor cycle: …












2.


Motor cycle type: …












3.


Manufacturer's name and address: …












4.


If applicable, name and address of manufacturer’s representative: …












5.


Engine












5.1.


Manufacturer: …












5.2.


Type: …












5.3.


Model: …












5.4.


Rated maximum net power: … kW at … min-1













5.5.


Kind of engine (e.g. positive-ignition, compression ignition, etc.): (3)…












5.6.


Cycles: two-stroke/four-stroke 2













5.7.


Cylinder capacity: … cm3













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 motor cycle 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
ref: … m












13.


Vehicle speeds of measurements in gear (i)












13.1.


Vehicle speed at the beginning of the period of acceleration (average of 3 runs) for gear (i): … km/h












13.2.


Pre-acceleration length for gear (i): … m












13.3.


Vehicle speed v
PP' (average of 3 runs) for gear (i): … km/h












13.4.


Vehicle speed v
BB' (average of 3 runs) for gear (i): … km/h












14.


Vehicle speeds of measurements in gear (i+1) (if applicable)












14.1.


Vehicle speed at the beginning of the period of acceleration (average of 3 runs) for gear (i+1): … km/h












14.2.


Pre-acceleration length for gear (i+1): … m












14.3.


Vehicle speed v
PP' (average of 3 runs) for gear (i+1): … km/h












14.4.


Vehicle speed v
BB' (average of 3 runs) for gear (i+1): … km/h












15.


Accelerations are calculated between lines AA' and BB'/PP' and BB'












15.1.


Description of functionality of devices used to stabilize the acceleration (if applicable): …












16.


Noise levels of moving vehicle












16.1.


Wide-open-throttle test result Lwot: … db(A)












16.2.


Constant speed test results Lcrs: … db(A)












16.3.


Partial power factor kp: …












16.4.


Final test result Lurban: … db(A)












17.


Noise level of stationary vehicle












17.1.


Position and orientation of microphone (according to Appendix 2 of Annex 3): …












17.2.


Test result for stationary test: … dB(A) at … min-1













18.


Additional sound emission provisions:











18.1.


RD-ASEP operating conditions


Reference Point
(a)


Reference Point
(b)


additional operating condition 1


additional operating condition 2


additional operating condition 3




gear i
i= 1 to n (number of gears)




18.1.1.


Selected gear number


 


 


 


 


 




1.8.1.2.


Approach condition to line AA’ (acceleration, deceleration or constant speed)


n.a.


n.a.


 


 


 




1.8.1.3.


Throttle control position (%)


n.a.


n.a.


 


 


 




18.1.4.


Vehicle speeds


-


-


-


-


-




18.1.4.1.


Vehicle speed at the beginning of the period of acceleration (average of 3 runs) (km/h)


 


 


n.a.


n.a.


n.a.




18.1.4.2.


Pre-acceleration length (m)


 


 


n.a.


n.a.


n.a.




18.1.4.3.


Vehicle speed vAA’

(average of 3 runs for Reference Points (a) and (b)) (km/h)


 


 


 


 


 




18.1.4.4.


Vehicle speed vPP’

(average of 3 runs for Reference Points (a) and (b)) (km/h)


 


 


 


 


 




18.1.4.5.


Vehicle speed vBB’

(average of 3 runs for Reference Points (a) and (b)) (km/h)


 


 


 


 


 




18.1.5.


Engine speeds


-


-


-


-


-




18.1.5.1.


Engine speed nAA’

(average of 3 runs for Reference Points (a) and (b)) (km/h)


 


 


 


 


 




18.1.5.2.


Engine speed nPP’

(average of 3 runs for Reference Points (a) and (b)) (km/h)


 


 


 


 


 




18.1.5.3.


Engine speed nBB’

(average of 3 runs for Reference Points (a) and (b) (min-1)


 


 


 


 


 




18.1.6.


Wide open throttle test result Lwot for Reference Points (a) and (b) (dB(A))


 


 


n.a.


n.a.


n.a.




18.1.7.


max. sound pressure level LASEP of the additional operating conditions


n.a.


n.a.


 


 


 




18.1.8.


RD-ASEP limit’


 


 


 


 


 











Note:


The columns for the additional operating conditions 1, 2 and 3 in the table above, need to be repeated for each gear that needs to be tested.
















18.2.


See manufacturer's statement of compliance with the requirements of paragraph 6.3.1. (attached).












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
PA: … 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
wot(i): … dB(A)












19.5.


User selectable software programs or modes with effect on either Lwot(i) or Lcrs or Lurb or LASEP













19.5.1.


List of user selectable software programs or modes: …












19.5.2.


User selectable software programs or modes used for the Lurb determination according to Annex 3: …












19.5.3.


User selectable software programs or modes used for Lwot and LASEP determination according to Annex 7: …












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: 2…












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.






(1)  Distinguishing number of the country which has granted/extended/refused or withdrawn approval

(2)  Delete what does not apply

(3)  If a non-conventional engine is used, this should be stated





ANNEX 2
Arrangements of approval marks

MODEL A

(See paragraph 5.5. of this Regulation)





a = 8 mm min
The above approval mark affixed to a motor cycle shows that the motor cycle type concerned has, with regard to noise, been approved in the Netherlands (E4) pursuant to Regulation No. 41 under approval number 052439. The first two digits of the approval number indicate that the approval was granted in accordance with the requirements of Regulation No. 41 as amended by the 05 series of amendments.

MODEL B

(See paragraph 5.6. of this Regulation)





a = 8 mm min
The above approval mark affixed to a motor cycle shows that the motor cycle type concerned has been approved in the Netherlands (E 4) pursuant to Regulations Nos. 41 and 10. The first two digits of the approval numbers indicate that on the date on which these approvals were granted, Regulation No. 41 included 05 series of amendments and Regulation No. 10 included the 01 series of amendments.





ANNEX 3
Methods and instruments for measuring noise made by motor cycles

1.   

Noise of the motor cycle in motion (measuring 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
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 30 ms.
The instruments shall be maintained and calibrated in accordance with the instructions of the instrument manufacturer.


1.1.1.2.   
Calibration
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 0.5 dB(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.


1.1.2.   
Instrumentation for speed measurements
The rotational speed of the engine shall be measured with an instrument meeting specification limits of at least ±2 percent or better at the engine speeds required for the measurements being performed. In case that there are other measurements correlated with the engine speeds, the calculated value may be used (e.g. calculation from the vehicle speed measurement).
The road speed of the vehicle shall be measured with instruments meeting specification limits of at least ±0.5 km/h when using continuous measuring devices.
If testing uses independent measurements of speed, this instrumentation shall meet specification limits of at least ±0.2 km/h. (1)



1.1.3.   
Meteorological instrumentation
The meteorological instrumentation used to monitor the environmental conditions during the test shall meet the following specifications:
±1 °C or less for a temperature measuring device;
±1.0 m/s for a wind speed measuring device;
±5 hPa for a barometric pressure measuring device;
±5 percent for a relative humidity measuring device.


1.2.   

Acoustical environment, meteorological conditions and background noise



1.2.1.   
Test site
The test site shall consist of a central acceleration section surrounded by a substantially level test area. The acceleration section shall be level; its surface shall be dry and so designed that rolling noise remains low.
On the test site the variations in the free sound field between the sound source at the centre of the acceleration section and the microphone shall be maintained to within 1 dB(A). This condition will be deemed to be met if there are no large objects which reflect sound, such as fences, rocks, bridges or buildings, within 50 m of the centre of the acceleration section. The road surface covering of the test site shall conform to ISO10844:2021.
The microphone shall not be obstructed in any way which could affect the sound field, and no person may stand between the microphone and the sound source. The observer carrying out the measurements shall take up position so as not to affect the readings of the measuring instrument.


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 5 m/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 10 s 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 10 dB(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 10 dB(A) and 15 dB(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 ±0.05 m.
The microphones shall be located 1.2 ±0.02 m 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'.


1.3.2.   

Conditions of the vehicle



1.3.2.1.   
General Conditions
The vehicle(s) tested shall be representative of vehicles to be put on the market under the vehicle type to be approved and selected by the manufacturer in agreement with the Type Approval Authority, to comply with the requirements of this Regulation.
Before the measurements are started, the vehicle shall be brought to its normal operating conditions.
If the motor cycle is fitted with fans with an automatic actuating mechanism, this system shall not be interfered with during the sound measurements. For motor cycles having more than one driven wheel, only the drive provided for normal road operation may be used.


1.3.2.2.   
Test mass of the vehicle
Measurements shall be made on vehicles at the following test mass m
t, in kg, specified as:

m
t = m
kerb + 75 ±5 kg
(75 ±5 kg equates to mass of the driver and instrumentation)


1.3.2.3.   
Tyre selection and condition
The tyres shall be appropriate for the vehicle and shall be inflated to the pressure recommended by the vehicle manufacturer for the test mass of the vehicle.
The tyres shall be selected by the vehicle manufacturer, and correspond to one of the tyre sizes and types designated for the vehicle by the vehicle manufacturer. The minimum tread depth shall be at least 80 percent of the full tread depth.


1.3.3.   

Operating conditions



1.3.3.1.   
General operating conditions
The path of the centreline of the vehicle shall follow the line CC' as closely as possible throughout the entire test, from the approach to line AA' until the rear of the vehicle passes line BB' +20m (see Annex 4 – Figure 1).


1.3.3.1.1.   
For full throttle acceleration tests the vehicle shall approach the line AA' at constant speed. When the front of the vehicle passes the line AA' the throttle control shall be shifted to the maximum throttle position as rapidly as possible and kept in this position until the rear of the vehicle passes the BB'. At this moment the throttle control shall be shifted to the idle position as rapidly as possible.
Unless specified otherwise the manufacturer may choose to use pre-acceleration in a full throttle acceleration test for the purpose of achieving a stable acceleration between the lines AA' and BB'. A test with pre-acceleration proceeds as described above except for the fact that the throttle control is shifted to the maximum throttle position already before the vehicle passes the line AA', namely when the front of the vehicle is still at a distance l
PA, the pre-acceleration length, from the line AA'.
The approach velocity shall be chosen such that the vehicle reaches a prescribed test speed v
test when its front passes the line PP'.


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'.



1.3.3.1.3.   

If the vehicle has user selectable software programs or modes, the test shall be conducted in a mode which does not restrict the vehicle’s power performance and which produces the highest Lwot(i). Manufacturer documentation is provided to the technical service responsible for conducting approval tests. Based on this documentation, the technical service selects the software program or mode to be tested



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 vtest = 40 ±1 km/h.










(b)


When the rear of the vehicle passes the line BB' the vehicle speed shall not exceed 75 percent 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 percent of v
test (i.e. 4 km/h) in case the exit speed v
BB' exceeds 75 percent of v
max 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 percent of v
max 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
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.


1.3.3.3.1.1.   
Test speed
The test speed v
test shall be:
40 ±1 km/h for vehicles with a PMR ≤ 50; and
50 ±1 km/h for vehicles with a PMR > 50.
If, in a given gear, the exit speed v
BB' exceeds 75 percent of the maximum speed v
max of the vehicle, the test speed for test in this gear shall be successively reduced by increments of 10 percent of v
test (i.e. 4 km/h or 5 km/h) until the exit speed v
BB' falls below 75 percent of v
max.


1.3.3.3.1.2.   
Reference acceleration and target acceleration
During the full throttle acceleration tests the vehicle shall reach the reference acceleration a
wot ref defined as:

a
wot ref = 2.47 * log(PMR) - 2.52 for vehicles with a PMR ≤ 50; and

a
wot ref = 3.33 * log(PMR) - 4.16 for vehicles with a PMR > 50
The results of these full throttle acceleration tests are used together with the results of constant speed tests to approximate a partial load acceleration typical for urban driving. The corresponding target acceleration a
urban is defined as:

a
urban = 1.37 * log(PMR) - 1.08 for vehicles with a PMR ≤ 50; and

a
urban = 1.28 * log(PMR) - 1.19 for vehicles with a PMR > 50.


1.3.3.3.1.3.   
Gear selection
It is the responsibility of the manufacturer to determine the correct manner of testing to achieve the required test speed and acceleration.


1.3.3.3.1.3.1.   
Vehicles with manual transmissions, automatic transmissions, or transmissions with continuously variable transmission ratios (CVT's) tested with locked gears
The selection of gears for the test depends on the specific acceleration under full throttle in the various gears in relation to the reference acceleration a
wot,ref required for the full-throttle acceleration tests according to paragraph 1.3.3.3.1.2. above.
The following conditions for the gear selection are possible:






(a)


If there are two gears that give an acceleration in a tolerance band of ±10 percent of the reference acceleration a
wot,ref, the gear nearest the reference acceleration shall be used for the test and shall be identified as such in the test report;










(b)


If only one specific gear gives an acceleration in the tolerance band of ±10 percent of the reference acceleration a
wot ref, the test shall be performed with that gear;










(c)


If none of the gears gives the required acceleration to within ±10 percent of the reference acceleration a
wot,ref, then tests shall be performed in two adjacent gears (i) and (i+1) chosen such that the gear (i), gives an acceleration higher and the gear (i+1) an acceleration lower than the reference acceleration a
wot,ref.




If the rated engine speed is exceeded in a gear before the vehicle passes BB', the next higher gear shall be used.
If the vehicle has more than one gear the first gear shall not be used. If awot,ref can only be achieved in first gear, second gear shall be used.


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 when the rear of the vehicle passes BB' + 20 m (see Annex 4 – Figure 1) shall be reduced by 1 dB(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 2.0 dB(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
AA'), BB' (v
BB'), and PP' (v
PP') shall be mathematically rounded to the nearest first decimal place (e.g. XX.X) and noted for further calculations.


1.4.2.   
Calculation of the acceleration
All accelerations are calculated using different speeds of the vehicle on the test track. Depending on the type of transmission the acceleration is either calculated between the lines AA' and BB' or between the lines PP' and BB' as specified below. The method used for the calculation of the acceleration shall be indicated in the test report.
In all of the following cases the acceleration is calculated between the lines AA' and BB' as specified in paragraph 1.4.2.1. below:






(a)


The vehicle is equipped with a manual transmission.










(b)


The vehicle is equipped with an automatic transmission or with a transmission with continuously variable gear ratios (CVT's) but tested with locked gear ratios.










(c)


The vehicle is equipped with an automatic transmission, an adaptive transmission or a transmission with variable gear ratios and tested with non-locked gear ratios, and electronic or mechanical devices, including alternative gear selector positions, are used to prevent a downshift to a gear which is typically not used at the specified test condition in urban traffic.




In all other cases the acceleration is calculated between the lines PP' and BB' as specified in paragraph 1.4.2.2. below.


1.4.2.1.   
Calculation of the acceleration between the lines AA' and BB'
The acceleration is calculated from measurements of the vehicle speed at the lines AA' and BB':

a
wot,(i),j = ((v
BB',j / 3.6)2 - (v
AA',j / 3.6)2) / (2 * (20 + l
ref))
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/s2;

l
ref is either the length of vehicle or 2 m, freely selectable by the vehicle manufacturer, Type Approval Authority and Technical Service.


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
wot,(i),j = ((v
BB',j / 3.6)2 - (v
PP',j / 3.6)2) / (2 * (10 + l
ref))
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/s2;

l
ref is either the length of vehicle or 2 m, 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
wot,(i) = (1 / 3) * (a
wot,(i),1 + a
wot,(i),2 + a
wot,(i),3)
The mean acceleration a
wot,(i) 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
wot,ref - a
wot,(i+1)) / (a
wot(i) - a
wot,(i+1))


1.4.4.   
Calculation of the partial power factor
The partial power factor k
p 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
p = 1 - (a
urban / a
wot,ref).


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
p = 1 - (a
urban / a
wot,(i))
If a
wot,(i) is equal to or less than a
urban, k
p is set to zero.


1.4.5.   
Processing of the sound pressure measurements
For a given test condition, the three individual results of each side of the vehicle shall be averaged separately:

L
mode,(i),side = (1 / 3) * (L
mode,(i),side,1 + L
mode,(i),side,2 + L
mode,(i),side,3)
Where the index "mode" refers to the test mode (full throttle acceleration or constant speed), "(i)" to the gear and "side" to the microphone position (left or right).
The higher value of the two averages shall be mathematically rounded to the nearest first decimal place (e.g. XX.X) and noted for further calculations:

L
mode,(i) = MAX (L
mode,(i),left ; L
mode,(i),right)


1.4.6.   

Calculation of the final test results



1.4.6.1.   
Vehicles with PMR ≤ 25
Vehicles with a PMR not exceeding 25 are tested in a single gear or gear selector position only under full throttle. The final test result is the sound pressure level L
wot,(i) mathematically rounded to the nearest first decimal place (e.g. XX.X).


1.4.6.2.   
Vehicles with PMR > 25
If the vehicle was tested in two gears the gear weighting factor is used to calculate the test results of the full throttle acceleration tests and of the constant speed tests:

L
wot = L
wot (i+1) + k * (L
wot,(i) - L
wot,(i+1))

L
crs = L
crs (i+1) + k * (L
crs,(i) - L
crs,(i+1))
If the vehicle was tested in a single gear or gear selector position no further weighting is necessary:

L
wot = L
wot,(i)


L
crs = L
crs,(i)

The sound pressure level L
urban representing urban driving is finally calculated using the partial power factor k
p:

L
urban = L
wot - k
p * (L
wot - L
crs)
All sound pressure levels are mathematically rounded to the nearest first decimal place (e.g. XX.X).


2.   

Noise from stationary motor cycle (measuring conditions and method for testing of the vehicle in use).



2.1.   
Sound-pressure level in the immediate vicinity of the motor cycle
In order to facilitate subsequent noise tests on motor cycles 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 motor cycle
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.


2.3.2.   
Test site
A suitable test site shall be outdoors and consist of a level concrete, dense asphalt with no appreciable level of porosity or similar hard material flat surface, free from snow, grass, loose soil, ashes or other sound-absorbing material. It shall be in an open space free from large reflecting surfaces, such as parked vehicles, buildings, billboards, trees, shrubbery, parallel walls, people, etc., within a 3 m radius from the microphone location and any point of the vehicle.
As an alternative to outside testing, a semi-anechoic chamber may be used. The semi-anechoic chamber shall fulfil the acoustical requirements given above. These requirements shall be met if the testing facility meets the 3 m distance criteria above and has a cut-off frequency below the lower of:






(a)


One-third-octave band below the lowest fundamental frequency of the engine during test conditions; and










(b)


100 Hz. (2)







2.3.3.   
Miscellaneous
Readings of the measuring instrument caused by ambient noise and wind effects shall be at least 10 dB(A) lower than the sound levels to be measured. A suitable windshield may be fitted to the microphone provided that account is taken of its effect on the sensitivity of the microphone.
The tests shall not be carried out if the wind speed, including gusts, exceeds 5 m/s during the sound-measurement interval.


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 ±0.01 m 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 0.2 m 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)


The reference point shall be at the end of the exhaust pipe,










(b)


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 or equal to 0.3 m apart and connected to a single silencer, only one measurement shall be made. The microphone shall be located relative to the outlet furthest from the vehicle's longitudinal centreline, or, when such outlet does not exist, to the outlet that is highest above the ground. The 0.3 m measurement is to be made along a single plane perpendicular to the flow axis of the exhaust gases.
For vehicles having an exhaust provided with outlets spaced more than 0.3 m 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 side of the body.

Figure 1


Reference point








2.4.2.   

Operating conditions



2.4.2.1.   
Target engine speed
The target engine speed is defined as
75 percent of S for vehicles with S ≤ 5,000 min–1, and
50 percent of S for vehicles with S > 5,000 min–1.
For a vehicle which cannot reach, in a stationary test, the target engine speed defined above, 95 percent of the maximum engine speed reachable in a stationary test shall be used instead as target engine speed.


2.4.2.2.   
Test procedure
The engine speed shall be gradually increased from idle to the target engine speed and held constant within a tolerance band of ±5 percent. Then the throttle control shall be rapidly released and the engine speed shall be returned to idle. The sound pressure level shall be measured during a period consisting of constant engine speed of at least 1 s and throughout the entire deceleration period. The maximum sound level meter reading shall be taken as the test value.
A measurement shall be regarded as valid only if the test engine speed did not deviate from the target engine speed by more than the specified tolerance of ±5 percent for at least 1 s.


2.4.3.   
Multi-mode exhaust system
Vehicles equipped with a multiple mode, manually adjustable exhaust system shall be tested in all modes.


2.5.   

Results



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 motor cycle.



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 2.0 dB(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 motor cycle 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 motor cycles, the following information relating to the sound-pressure level measurements carried out in accordance with paragraph 1. of Annex 3 for the motor cycle 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
PA 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
wot,(i) 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.




(1)  Independent measurements of speed are when two or more separate devices will determine the values of vAA', vBB' and vPP'. A continuous measuring device such as radar will determine all required speed information with one device.

(2)  The noise performance of indoor testing facilities is specified in terms of the cut-off frequency (Hz). This is the frequency above which the room can be assumed to act as a semi-anechoic space.





Annex 3 - Appendix 1
Flowchart of the test procedure for the test of the vehicle in motion for vehicles of category L3 with PMR ≤ 25










Annex 3 - Appendix 2
Positioning of the microphones for the stationary noise test





Dimensions in metres, unless otherwise indicated





ANNEX 4
Test track layout

Figure 1


Test track layout with dimensions in meters






Key













Minimum area covered with test road surface, i.e. test area











Microphone positions (height 1,2m)









ANNEX 5
Exhaust or silencing systems containing fibrous material

1.   

Fibrous absorbent material shall be asbestos-free and may be used in the construction of the exhaust or silencing system only if suitable devices ensure that the fibrous material is kept in place for the whole time that the exhaust or silencing system is being used and the exhaust or silencing system meets the requirements of any one of paragraphs 1.1., 1.2.,1.3. or 1.4.:



1.1.   

After removal of the fibrous material, the sound level shall comply with the requirements of paragraph 6 of this Regulation.



1.2.   

The fibrous absorbent material may not be placed in those parts of the silencer through which the exhaust gases pass and shall comply with the following requirements:



1.2.1.   

The material shall 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 percent of the material shall 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 2559:2000.



1.2.3.   
The loss in weight of the material shall not exceed 10.5 percent after soaking for 24 hours at 90 ± 5°C in a synthetic condensate of the following composition: (1)

1 N hydrobromic acid (HBr): 10 ml
1 N sulphuric acid (H2SO4): 10 ml
Distilled water to make up to 1,000 ml


1.3.   

Before the system is tested in accordance with Annex 3, it shall 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 motor cycles, the minimum distances to be completed during conditioning are:






Class of motor cycle according to
Power-to-Mass Ratio index (PMR)


Distance (km)




Class I < 25
Class II > 25 < 50
Class III > 50


4,000 
6,000 
8,000 






1.3.1.2.   

50 ±10 percent 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 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 three hours' 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 motor cycle or to the engine. In the former case, the motor cycle 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 100 mm downstream of the intake flange, reaches a value of between 35 and 40 kPa. 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 percent of the maximum that can be measured before the engine stops. It shall close when this pressure does not differ by more than 10 percent 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 percent of the rated engine speed (S).



1.3.2.6.   

The power indicated by the dynamometer shall be 50 percent of the full-throttle power measured at 75 percent 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 48 hours. 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 motor cycle 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 motor cycle for which the exhaust system was designed. The number of cycles for each class of motor cycle is:






Class of motor cycle according to
Power-toMass Ratio index (PMR)


Number of cycles




Class I < 25
Class II > 25 < 50
Class III > 50


6 
9 
12 






1.3.3.3.   

Each test-bench cycle shall be followed by a break of at least six hours in order to reproduce the effects of cooling and condensation.



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


Duration of phase in minutes




PMR < 50


PMR > 50




1
2
3
4
5
6


Idling
25 % load at 75 % S

50 % load at 75 % S

100 % load at 75 % S

50 % load at 100 % S

25 % load at 100 % S



6 
40 
40 
30 
12 
22 


6 
50 
50 
10 
12 
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 the exhaust gas outlet does not exceed that measured when the motor cycle is running at 110 km/h or 75 percent of S in top gear. The engine and/or motor cycle speeds are determined to within ±3 percent.



1.4.   
Exhaust gases are not in contact with fibrous materials and fibrous materials are not under the influence of pressure variations.

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 and a filling time of not less than 1 second.










4.


Pressure switch with an operating range of 5 kPa to 250 kPa.










5.


Time delay switch.










6.


Impulse counter.










7.


Quick response valve, such as exhaust brake valve 60 mm in diameter, operated by a pneumatic cylinder with an output of 120 N at 400 kPa. The response time, both when opening and closing, shall not exceed 0.5 seconds.










8.


Exhaust gas evacuation.










9.


Flexible pipe.










10.


Pressure gauge.






(1)  The material shall be washed in distilled water and dried for one hour at 105 °C before weighing.





ANNEX 6
Maximum limits of sound levels







Category


Power-to-mass ratio index (PMR)


Limit value for Lurban in dB(A)




First category


PMR ≤ 25


73 




Second category


25 < PMR ≤ 50


74 




Third category


PMR > 50


77 









ANNEX 7
Real Driving Additional Sound Emission Provisions (RD-ASEP)

1.   

Scope



1.1.   

This annex applies to vehicles of category L3 with PMR >50.



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.   
RD-ASEP control range
The requirements of this annex apply to any vehicle operation with the following restrictions:






(a)


vAA' shall be at least 10 km/h










(b)


vBB' shall not exceed 80 km/h for vehicles with PMR≤150
vBB’ shall not exceed 100 km/h for vehicles with PMR>150










(c)


nAA' shall be equal to or greater than nAA',min

nAA',min = 0,1 * (S – nidle) + nidle











(d)


nBB' shall be equal to or less than nBB',max





For vehicles tested in locked gears: nBB',max = 0,8 × S
For vehicles tested in non-locked gear ratios: nBB',max = S
The values for the RD-ASEP control range shall be seen as absolute values and shall not be increased or lowered by addition or subtraction of the tolerance as indicated in paragraph 2.8. of this Annex.


2.6.   
RD-ASEP limits
The maximum noise level recorded during the passage of the motorcycle through the test track shall not exceed:
for nPP' < nwot,(i)

Lwot,(i) + (1 * (nPP' – nwot,(i)) /1000) + 3
and for nPP' ≥ nwot,(i)











Where Lwot,(i) and nPP' have the same meaning as in paragraph 1. of Annex 3 and nwot,(i) refers to the corresponding engine speed when the front of the vehicle passes the line PP'. The index "(i)" refers to the gear used, nAA’,min is the engine speed as defined in paragraph 2.5.(c) of this Annex and nBB’,max is the engine speed as defined in paragraph 2.5.(d) of this Annex.
If the tests according to Annex 3 of this UN Regulation and the RD-ASEP tests are performed with the same vehicle in immediate sequence, the values for Lwot(i) and nwot(i) from the Annex 3 test may be used, if agreed by the type approval authority. Otherwise, when compliance with these limits is checked, values for Lwot(i) and nwot(i) shall be newly determined by measurements as defined in paragraph 1. of Annex 3, however using the same gear (i), the same user selectable drive mode and the same pre-acceleration distance as during type approval.


2.7.   
Facilities
Due to limitations of test facilities and in respect of safety, not every test condition may be safely performed on every test facility.
Notwithstanding such restrictions, the type approval shall be granted on these test facilities, however the vehicle has to comply to all provisions of this Annex 7. In these cases, the vehicle manufacturer shall explain to the satisfaction of the authority present at type approval that the vehicle fulfils the requirements which could not be tested due to the restriction of the test facility.


2.8.   
Tolerances
For tests according to paragraphs 3.2.2. (b) and 3.3. of this Annex, a tolerance of +/- 5km/h shall apply, while still respecting the boundaries of the RD-ASEP control range defined in paragraph 2.5 of this Annex.
Examples for paragraph 3.2.2. (b) of this Annex:






—


requested vBB’=95 km/h → valid vBB’= 90-100 km/h










—


requested vBB’=100 km/h → valid vBB’= 95-100 km/h




Examples for paragraph 3.3. of this Annex:






—


requested vtest=10 km/h → valid vAA’= 10-15 km/h










—


requested vtest=15 km/h → valid vAA’= 10-20 km/h










—


requested vtest=75 km/h → valid vAA’= 70-80 km/h










—


requested vtest=95 km/h → valid vAA’= 90-100 km/h










—


requested vtest=100 km/h → valid vAA’= 95-100 km/h






3.   

Testing compliance by measurements (1)




3.1.   
General
The Type Approval Authority as well as the technical service shall request tests to check the compliance of the motorcycle with the requirements of paragraph 2 of this Annex. To avoid undue workload, testing is restricted to the reference points defined in paragraph 3.2 of this Annex and the additional operating conditions as defined in paragraph 3.3. of this Annex.
For vehicles with manual transmissions, the total number of operating conditions to be tested according to paragraph 3.3. of this Annex is defined by the number of gears of the vehicle multiplied by 3, and reduced by the number of operating conditions which were applied for tests according to paragraph 3.2 of this Annex and for the determination of Lurb according to Annex 3.
For vehicles with variable gear ratios or automatic transmission with non-lockable gear ratios the total number of operating conditions to be tested according to paragraph 3.3. of this Annex is defined as 6, and reduced by the number of operating conditions which were applied for tests according to paragraph 3.2 of this Annex and for the determination of Lurb according to Annex 3.
Notwithstanding the above, a minimum of 3 operating conditions shall be tested according to paragraph 3.3. of this Annex.


3.2.   

RD-ASEP reference test conditions



3.2.1.   
Test procedure
When the front of the vehicle reaches AA', the throttle shall be fully engaged and held fully engaged until the rear of the vehicle reaches BB'. The throttle shall then be returned as quickly as possible to the idle position. Pre-acceleration may be used if acceleration is delayed beyond AA'. The location of the start of the acceleration shall be reported.


3.2.2.   
Test speed and gear selection
The vehicle shall be tested at each of the following operating conditions:






(a)


vPP' = 50 km/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.










(b)


vBB' corresponding to nBB' = nBB’,max as defined in paragraph 2.5 (d)
vBB' shall not exceed the values as specified in paragraph 2.5 (b) of this Annex.




The selected gear shall be 2nd. If the 3rd gear satisfies requirements of nBB' and vBB', 3rd shall be used. If the 4th gear satisfies requirements of nBB' and vBB', 4th shall be used. If the 5th gear satisfies requirements of nBB' and vBB', 5th shall be used. If the 6th gear satisfies requirements of nBB' and vBB', 6th shall be used.
If in 2nd gear under the above-mentioned condition for nBB’ the vehicle speed at line BB’ would exceed the value for vBB’ as specified in paragraph 2.5 of this Annex, the test shall be performed in 2nd gear and a maximum vehicle speed as specified in paragraph 2.5 of this Annex shall be reached at line BB’ instead.
If during the test unusual riding conditions (such as apparent wheel spin or front wheel lift up) occur, the test shall be performed in the next higher gear, and the maximum vehicle speed as specified in paragraph 2.5 of this Annex shall be reached at line BB’ instead.


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-1 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.


3.3.   

Additional operating conditions



3.3.1.   
Test procedure
The vehicle shall approach the line AA' at constant speed or in acceleration or deceleration, according to the throttle operation which may be requested by the technical service responsible for conducting approval tests in agreement with the type approval authorities.
The approach velocity shall be chosen as such that the vehicle reaches a prescribed test speed vtest when its front passes the line AA'.
When the front of the vehicle passes the line AA' the throttle control shall be adjusted as rapidly as possible to a position (partial throttle, wide open throttle or maintain present throttle control position) defined by the technical service responsible for conducting approval tests and shall be kept in this position until the rear of the vehicle passes line BB’.
When the rear of the vehicle passes line BB' the throttle control shall be shifted to the idle position as rapidly as possible.
The throttle position between lines AA’ and BB’ shall not result in a deceleration of the vehicle. A deceleration is present when:






—


vPP’ < vAA’ - 5km/h, or










—


vBB’ < vAA’ - 5km/h, or










—


vBB’ < vPP’ - 5km/h.






3.3.2.   
Test speed, gear and mode selection and throttle operation
The conditions of this paragraph shall be defined by the technical service responsible for conducting the approval tests.
To assist defining these conditions, manufacturer documentation is provided to the technical service responsible for conducting approval tests. The technical service responsible for conducting approval tests can request pre-testing of the vehicle.
The test speed vtest may be any speed within the RD-ASEP control range as defined in paragraph 2.5. of this Annex. The vehicle may be tested in any of the available gears, including the 1st gear.
Within the total number of additional operating conditions defined in paragraph 3.1 of this Annex, the vehicle may be tested in any of the available user selectable software programs or modes.
The throttle operation shall be in accordance with paragraph 3.3.1. of this Annex.
The throttle operation before line AA’ and between lines AA’ and BB’ shall be defined and described in a way that it can be performed by a skilled rider who has made himself familiar with the riding characteristics of the test vehicle and that the correct execution can be assessed by observation without the necessity of technical equipment on the vehicle or at the test site other than the equipment which is required for the tests according to Annex 3.
If the requested operating conditions lead to a riding condition which may not be expected to occur when the vehicle is operated in real traffic (for example, front wheel lift up, apparent wheel spin, chain slap, engine lugging), that test run shall be discarded and a test run with different operating conditions shall be performed.


3.3.3.   

Data processing and reporting



3.3.3.1.   
The maximum A-weighted sound pressure level "L" indicated during the passage of the vehicle between AA' and when the rear of the vehicle passes BB' + 20 m (see Annex 4 – Figure 1) shall be reduced by 1 dB(A) to account for measurement inaccuracy and mathematically rounded to the nearest first decimal place (e.g. XX.X) for each microphone position (2).
If a sound peak obviously out of character with the general sound pressure level is observed, the measurement shall be discarded, and the test run shall be repeated with the same operating conditions.


3.3.3.2.   
Processing of the sound pressure measurements and calculation of the final test results
LASEP = MAX (LASEP,left; LASEP,right)
Where the index "left, “right” refers to the microphone position (left or right).


3.3.3.3.   

The engine speed values at AA', BB', and PP' in units of min-1 shall be mathematically rounded to the nearest integer for further calculations



3.3.3.4.   

The final sound pressure levels for the additional operating conditions shall not exceed the limits specified in paragraph 2.6. of this Annex.




(1)  It is recommended that the rider who is performing the tests is making himself familiar with the riding characteristics of the test vehicle before he performs the test runs.

(2)  The sound pressure level "L" is determined by a single test run.





ANNEX 8
Statement of compliance with the Additional Sound Emission Provisions (ASEP)
(Maximum format: A4 (210 × 297 mm))
… (Name of manufacturer) attests that vehicles of this type … (type with regard to its noise emission pursuant to Regulation No. 41) comply with the requirements of paragraph 6.3. of Regulation No. 41.
… (Name of manufacturer) makes this statement in good faith, after having performed an appropriate evaluation of the sound emission performance of the vehicles.
Date: …
Name of authorized representative: …
Signature of authorized representative: …



ELI: http://data.europa.eu/eli/reg/2025/2412/oj
ISSN 1977-0677 (electronic edition)