UN R90 Supplement 10 (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 10 to the 02 series of amendments
Supplement 9 → 10
- What changed
- Paragraph 2.3. of Annex 15 now says “same or lower than the reference disc” instead of “same or higher”.
- The tolerance in paragraph 2.3. is now “+20 per cent maximum” instead of “– 20 per cent maximum”.
- Why
- A misprint was made in paragraph 2.3. when Amendment 8 to UN Regulation No. 90 was implemented.
- The old text allowed discs that are more stressed than the reference disc in the same homologation group.
Q1What changed1 change
Braking surface lightening in groups of discs (Annex 15, para. 2.3.)
Annex 15 gives the criteria for groups of discs for vehicles of categories L1, L2, L3, L4 and L5. Paragraph 2.3. allows any braking surface lightening solution, for example holes, slots or wave, with one condition. The ratio between the vehicle kinetic energy to the mass of the disc braking surface must be same or lower than the reference disc. The tolerance is +20 per cent maximum. Before this supplement, the text said “same or higher than the reference disc” and “– 20 per cent maximum”.
Q2Why it changed
- Proposed by
- Expert from Italy
- Working party
- GRVA, 14th session (September 2022)
Reasons
Reasons given by the proposer: Expert from Italy, in informal document GRVA-14-17. GRVA adopted a text based on GRVA-14-17 at its fourteenth session and submitted it to WP.29 and AC.1.
A misprint was made when Amendment 8 to UN Regulation No. 90 was implemented.
Source
“While implementing Amendment 8 to R90 regulation a misprint was made.”
The braking surface lightening criteria in paragraph 2.3. were defined incorrectly. The old text allowed discs that are more stressed than the reference disc in the same homologation group.
Sources (2)
“In particular, on Par. 2.3 the braking surface lightening criteria is incorrectly defined.”
“The current definition allows to insert in the same homologation group discs that are more stressed than the reference disc.”
The proposed modification clearly states which disc is the reference disc used for disc group definition. It must be the one with the highest braking surface lightening with respect to the motorcycle application (so the highest ratio).
Source
“The proposed modification clearly states that the reference disc used for disc group definition shall be the one with the highest braking surface lightening with respect to the motorcycle application (so highest ratio).”
Document trail
- —ProposalGRVA-14-17Proposal by the expert from Italy
- 2022-11Sent to WP.29ECE/TRANS/WP.29/2022/148Text that GRVA adopted and sent to WP.29 and AC.1
- 2022-11WP.29 adoptsECE/TRANS/WP.29/1168Adopted at the 188th session (session report, para. 138)
- 2023-06-05In forceC.N.172.2023.TREATIES-XI.B.16.90UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- Keep Annex 15 group discs' paragraph 2.3. ratio same or lower than the reference disc, tolerance +20 per cent maximum.
Technical service / Approval authority
- Check Annex 15 group discs: paragraph 2.3. ratio same or lower than the reference disc, tolerance +20 per cent maximum.
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ⓘ This report gives advice only. It is not legal or type-approval advice.