UN R41 Supplement 8 (04 series) · UNECE Regulation No. 41 (ECE R41) — Uniform provisions concerning the approval of motorcycles with regard to noise.
UN R41 — Supplement 8 to the 04 series of amendments
Supplement 7 → 8
- What changed
- New paragraph 5.2.2. says that multiple exhaust or silencing system configurations must be explicitly listed under the same type approval with their respective test results.
- Paragraph 5.2.1. no longer bars a Contracting Party from giving the same number to the same motorcycle type with another exhaust or silencing system type.
- For outlets spaced less than or equal to 0.3 m apart and connected to separate silencers, Annex 3 now requires only one measurement.
- Why
- The proposal intends to minimize the proliferation of approval numbers from models with differences in vehicle exhaust and silencing systems.
- The proposal says that the type definition language, in its strictest sense, does not allow multiple configurations to be listed on the same approval certificate.
- For the microphone position, GRBP-71-10 says that misinterpretation because of ambiguity in the language causes improper stationary noise measurements.
Q1What changed31 changes
Type of motorcycle as regards its sound level (paras. 2.1. to 2.2.3.)
Paragraph 2.2. now defines the “Type of motorcycle as regards its sound level”, without the words “and exhaust system”. In paragraph 2.2.1., the type of engine now includes the number and capacity of cylinders “or rotors”. In paragraph 2.2.2., the transmission system now includes, in particular, the overall gear ratio taking into account the rear wheel circumference. Paragraph 2.2.3. now says “Configurations and arrangements of exhaust or silencing systems” instead of “Number, type and arrangement of exhaust or silencing systems”. Paragraph 2.1. now uses “motorcycle” instead of “motor cycle”.
Exhaust or silencing system terms (paras. 2.3. to 2.4.1.)
Paragraph 2.3.2. now uses the term “Non-Original Replacement Exhaust or Silencing System (NORESS)” instead of “Non-original exhaust or silencing system”. Paragraph 2.4. now defines “Exhaust or silencing systems of differing configurations” instead of “Exhaust or silencing systems of differing types”. In paragraph 2.3., “motor cycle” is now “motorcycle”. In paragraph 2.4.1., “trade marks” is now “trademarks”.
Application documents, samples and motorcycles for each configuration (paras. 3.3. to 3.6.)
New paragraph 3.3. applies if multiple configurations are applicable to the motorcycle type to be approved. Then the documents of paragraph 3.2. must be prepared for each exhaust or silencing system configuration. Former paragraph 3.3. is now paragraph 3.4., and it now adds the words “in agreement with the type approval authorities” and asks for a sample of the exhaust or silencing system(s). Former paragraph 3.4. is now paragraph 3.5., and it now says “All motorcycle(s) representative of the same type with all possible exhaust or silencing system configurations to be approved”. Before, it said “A motor cycle representative of the motor cycle type to be approved”. Former paragraph 3.5. is now paragraph 3.6.
Approval number and multiple exhaust configurations (paras. 5.2.1. to 5.9.)
Former paragraphs 5.2. and 5.4. to 5.8. are now paragraphs 5.2.1. and 5.5. to 5.9. Paragraph 5.2.1. no longer bars a Contracting Party from giving the same number to the same motorcycle type with another exhaust or silencing system type. The same Contracting Party still may not assign the same number to another motorcycle type. New paragraph 5.2.2. says that multiple exhaust or silencing system configurations must be explicitly listed under the same type approval with their respective test results. New paragraph 5.4. says that the respective information for these configurations must be provided for in Annex 1. In paragraph 5.3., “motor cycle” is now “motorcycle”, and the A4 size is now written “210 × 297 mm”.
General conditions for the vehicles tested (Annex 3, para. 1.3.2.1.)
The vehicle(s) tested must be representative of vehicles to be put on the market under the vehicle type to be approved. The text adds “selected by the manufacturer in agreement with the Type Approval Authority”. Before, the vehicle had to be supplied as specified by the vehicle manufacturer.
Microphone position for several exhaust outlets (Annex 3, para. 2.4.1., and Appendix 2)
For outlets connected to a single silencer, the one-measurement rule now applies to a spacing of less than or equal to 0.3 m. Before, it applied to a spacing of less than 0.3 m. In this case, the 0.3 m measurement is to be made along a single plane perpendicular to the flow axis of the exhaust gases. A new paragraph requires only one measurement for outlets spaced less than or equal to 0.3 m apart and connected to separate silencers. For the purpose of roadside checking, the reference point may now be moved to “the outer side of the body” instead of “the outer surface of the vehicle body”. The figure in Appendix 2 to Annex 3 is changed.
Filling time of the compensating reservoir (Annex 5, Figure 1, note 3)
Note 3 to Figure 1 now gives the compensating reservoir a filling time of not less than 1 second. The maximum capacity of 40 litres does not change.
Q2Why it changed
- Proposed by
- Expert from the International Motorcycle Manufacturers Association
- Working party
- GRBP, 71st session (January 2020)
Reasons
The proposal intends to minimize the proliferation of approval numbers from models with differences in vehicle exhaust and silencing systems. The proposal says that this change will reduce redundancy and minimize the chances for documentation errors.
Sources (2)
“The intention of this proposal is to minimize proliferation of approval numbers from models with differences in vehicle exhaust and silencing systems.”
“This change will reduce redundancy and minimize the chances for documentation errors.”
The proposal says that the type definition language, in its strictest sense, does not allow multiple configurations to be listed on the same approval certificate. Examples of configurations are different exhausts, intakes or engine displacements. A separate approval number and document must be generated for each unique configuration. Approvals to UN Regulation No. 41 are used by more and more countries around the world. The proposal says that the increase in approval numbers and documentation burden can become unmanageable and burdensome for manufacturers and type approval authorities.
Sources (4)
“The current type definition language, in its strictest sense, does not allow for multiple configurations, such as different exhausts, intakes or engine displacements, to be listed on the same approval certificate.”
“A separate approval number and document must be generated for each unique configuration.”
“As approvals according to UN Regulation No. 41 are utilized by more and more countries around the world, the increase in approval numbers and documentation burden”
“can grow to a point becoming unmanageable and burdensome for the manufacturers and type approval authorities.”
The proposal on the compensating reservoir intends to correct an omission, which requires conditioning by pulsation. The proposal says that this is in line with other noise UN Regulations Nos. 9, 51 and 63.
Sources (2)
“The intention of this proposal is to correct an omission, which requires conditioning by pulsation, in line with other noise UN Regulations Nos. 9, 51 and 63.”
“Compensating reservoir with a maximum capacity of 40 litres and a filling time of”
Proposer's reason (informal document GRBP-71-10)
The proposal is to align the stationary microphone positioning of UN R41-04 and ISO 5130. The reason is to prevent the regular misinterpretation that happens because of ambiguity in the language. This misinterpretation causes improper stationary noise measurements. These lead to customer satisfaction complaints, false reports of non-compliance and enforcement issues.
Submitted by IMMA. Working party adoption: ECE/TRANS/WP.29/GRBP/69, para. 5.
Sources (2)
“The reason of proposing to align UN R41-04 and ISO 5130 stationary microphone positioning is to prevent the regular misinterpretation that happens because of ambiguity in the language.”
“This causes improper stationary noise measurements leading to: customer satisfaction complaints, false reports of non-compliance and enforcement issues.”
Proposer's reason (informal document GRBP-71-10)
Stationary noise measurements on a single sided dual exhaust system can vary by approximately 4 dB from the lower to the upper muffler. The proposal says that the text at that time did not address single sided dual exhaust systems with separate silencers. It also did not address systems spaced at 0.3 m, or how to measure the 0.3 m spacing.
Submitted by IMMA. Working party adoption: ECE/TRANS/WP.29/GRBP/69, para. 5.
Sources (2)
“Stationary noise measurements on a single sided dual exhaust system can vary by approximately 4dB from the lower to upper muffler.”
“The current language does not address single sided dual exhaust systems which have separate silencers, does not address systems that are spaced at 0.3 m, and does not address how to measure the 0.3 m spacing.”
Document trail
- 2019-06ProposalECE/TRANS/WP.29/GRBP/2019/24Proposal by IMMA on the compensating reservoir
- —Working party adoptsECE/TRANS/WP.29/GRBP/68Session report, para. 5: proposal adopted, submission postponed
- 2019-11RevisedECE/TRANS/WP.29/GRBP/2019/25/Rev.1Revised proposal by IMMA on approval numbers
- —ProposalGRBP-71-10Proposal by IMMA on the microphone position
- —Working party adoptsECE/TRANS/WP.29/GRBP/69Session report, paras. 3 and 5
- 2020-03Sent to WP.29ECE/TRANS/WP.29/2020/70Text that GRBP sent to WP.29 and AC.1
- 2020-06WP.29 adoptsAdopted at the 181st session
- 2021-01-03In forceC.N.22.2021.TREATIES-XI.B.16.41UN depositary notification
Q3Who is affected
Vehicle manufacturer
- Make sure that the paragraph 3.2. documents are prepared for each exhaust or silencing system configuration, if multiple configurations apply.
- Be ready to submit motorcycles representative of the type with all possible exhaust or silencing system configurations to be approved.
- Select test vehicles representative of vehicles to be put on the market under the type, with Type Approval Authority agreement.
Component supplier
- No direct action for this role.
Technical service / Approval authority
- For outlets spaced less than or equal to 0.3 m apart on separate silencers, make only one measurement.
- For a single silencer, measure the 0.3 m spacing along a single plane perpendicular to the exhaust gas flow axis.
- Check that the Annex 5 compensating reservoir has a filling time of not less than 1 second.
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ⓘ This report gives advice only. It is not legal or type-approval advice.
More UN R41 change reports
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- 06 series — Base text
- 05 series — Supplement 5
- 05 series — Supplement 4
- 05 series — Supplement 3
- 05 series — Supplement 2
- 05 series — Supplement 1
- 05 series — Base text
- 04 series — Supplement 13
- 04 series — Supplement 12
- 04 series — Supplement 11
- 04 series — Supplement 10
- 04 series — Supplement 9
- 04 series — Supplement 7