UN R90 Supplement 7 (02 series) · UNECE Regulation No. 90 (ECE R90) — Uniform provisions concerning the approval of replacement brake lining assemblies, drum-brake linings and discs and drums for power-driven vehicles and their trailers.
UN R90 — Supplement 7 to the 02 series of amendments
Supplement 6 → 7
- What changed
- New paragraph 3.1.1.1. of Annex 9 allows an alternative disc brake and brake disc, with a disc diameter of 278 ± 2 mm. This set-up is such as to allow a rectangular piece of the friction material to be attached to the backing plates of the disc brake.
- With the alternative hardware, the Registered Values of friction for ongoing COP checks must be established in accordance with the technical service by comparative tests.
- The applicant must provide the friction behaviour values from the alternative test hardware in accordance with Annex 9, paragraph 3.4.1. The results must be attached to the type-approval report.
- Why
- Paragraph 3.1.1. requires a very specific type and size of brake calliper and brake disc, but such brakes are no longer in series production.
- Approval holders find it increasingly difficult to fulfil their routine CoP obligations, because they cannot locate and buy the prescribed hardware.
- The changed proposal still requires the same disc diameter and pad area and thickness, to give consistency with past data.
Q1What changed3 changes
Alternative disc brake and brake disc for the machine (Annex 9, para. 3.1.1.1.)
This part of Annex 9 covers brake lining assemblies and drum brake linings for vehicles of categories M3, N2, N3, O3, and O4. Alternatively, the machine may be equipped with a disc brake and corresponding brake disc having a diameter of 278 ± 2 mm. This set-up is such as to allow a rectangular piece of the friction material to be attached to the backing plates of the disc brake. The piece has a surface area of 44 cm² ± 0.5 cm² and a thickness of at least 6 mm. Paragraph 3.1.1. specifies a disc brake of the fixed calliper type with a cylinder diameter of 60 mm and a solid (not ventilated) disc. That disc has a diameter of 278 ± 2 mm and a thickness of 12 mm ± 0.5 mm.
Registered Values of friction with the alternative hardware (Annex 9, para. 3.1.1.1.)
With the alternative hardware, the Registered Values of friction for ongoing COP checks must be established in accordance with the technical service by comparative tests. These tests use the same batch of friction material with the test hardware specified in 3.1.1. and with the alternative hardware. The applicant must provide the values for the friction behaviour from the alternative test hardware in accordance with Annex 9, paragraph 3.4.1. The results must be attached to the type-approval report.
Q2Why it changed
- Proposed by
- Expert from the European Association of Automotive Suppliers (CLEPA)
- Working party
- GRVA, 10th session (May 2021)
Reasons
Paragraph 3.1.1. of Annex 9 covers CoP testing of brake lining assemblies and drum brake linings for categories M3, N2, N3, O3, and O4. It requires a very specific type and size of brake calliper and brake disc. The purpose is to let the brake lining manufacturer demonstrate to the approving authority the consistency of production, batch to batch.
Sources (2)
“Paragraph 3.1.1. of Annex 9 in UN Regulation No. 90, covering CoP testing for brake lining assemblies and drum brake linings for vehicles of categories M3, N2, N3, O3, and O4”
“currently requires the use of a very specific type and size of brake calliper and brake disc in order for the brake lining manufacturer to be able to demonstrate to the approving authority the consistency of production, batch to batch.”
This type of brake calliper and brake rotor was commonly available in the early 1990s, when the Regulation was first published. This is no longer the case. All major brake calliper manufacturers confirm that such brakes are no longer in series production.
Sources (2)
“This type of brake calliper and corresponding brake rotor were commonly available when the Regulation was first published in the early 1990’s but this is no longer the case”
“with all major brake calliper manufacturers confirming that such brakes are no longer in series production.”
As a result, holders of UN Regulation No. 90 approvals find it increasingly difficult to fulfil their routine CoP obligations. They cannot locate and buy the specifically prescribed hardware to do the tests.
Source
“holders of UN Regulation No. 90 approvals around the world are finding it increasingly difficult to fulfil their routine CoP obligations because they cannot any longer locate and purchase the specifically prescribed hardware in order to conduct the tests.”
It is anticipated that, to change to new hardware, the manufacturer will need a new set of baseline tests with the new hardware. It is anticipated that the manufacturer will do these tests in agreement with the Type Approval Authority. These tests “re-establish/re-confirm” CoP values to use as the reference data going forward.
Sources (2)
“it is anticipated that it will be necessary for the manufacturer, in agreement with the Type Approval Authority, to conduct a new set of baseline tests with the new hardware”
“to “re-establish/re-confirm” CoP values to use as the reference data going forward.”
Proposer's reason (informal document GRVA-10-28)
The changed proposal allows also alternative forms of brake calliper (for example, floating types) and brake discs (for example, vented). It still requires the same disc diameter and pad area and thickness, as currently specified, to give consistency with past data.
Submitted by Expert from the European Association of Automotive Suppliers (CLEPA). Working party adoption: ECE/TRANS/WP.29/GRVA/10, para. 87.
Sources (2)
“It is therefore proposed to amend the regulation to allow also the use of alternative forms of brake calliper (e.g. floating types) and brake discs (e.g. vented)”
“but still require the use of the same disc diameter and pad area and thickness, as currently specified, in order to provide consistency with past data.”
Document trail
- —ProposalGRVA-07-52Informal proposal by CLEPA
- 2020-11ProposalECE/TRANS/WP.29/GRVA/2021/15Proposal by CLEPA, based on GRVA-07-52
- —Amended in sessionGRVA-10-28Amendments by CLEPA to the proposal
- —Working party adoptsECE/TRANS/WP.29/GRVA/10Session report, para. 87
- 2021-09Sent to WP.29ECE/TRANS/WP.29/2021/139Text that GRVA sent to WP.29 and AC.1
- 2021-11WP.29 adoptsECE/TRANS/WP.29/1161Adopted at the 185th session (session report, para. 121)
- 2022-06-22In forceC.N.223.2022.TREATIES-XI.B.16.90UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- In the case of paragraph 3.1.1.1., be ready for comparative tests with the same batch of friction material.
- In the case of paragraph 3.1.1.1., give the friction values from the alternative hardware as Annex 9, paragraph 3.4.1. requires.
Technical service / Approval authority
- In the case of paragraph 3.1.1.1., be ready for comparative tests that establish Registered Values of friction for COP checks.
- In the case of paragraph 3.1.1.1., check that the alternative hardware results are attached to the type-approval report.
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ⓘ This report gives advice only. It is not legal or type-approval advice.