UN R75 Supplement 20 (00 series) · UNECE Regulation No. 75 (ECE R75) — Uniform provisions concerning the approval of pneumatic tyres for L-category vehicles.
UN R75 — Supplement 20 to the 00 series of amendments
Supplement 19 → 20
- What changed
- Special tyres declared by the tyre manufacturer at paragraph 4.1.3. as complying also with paragraph 2.33. now take the “M+S”, “M.S” or “M&S” inscription.
- The “snow tyre” definition (paragraph 2.33.) now says “in mud and/or snow conditions” and “initiate and control vehicle motion”.
- Paragraph 2.20.6. now says that tyres not intended to be fitted on rims designed for motorcycles must not be marked with M/C.
- Why
- Before this supplement, the Regulation did not consider the case of a “special tyre” that can also fulfil the definition of a “snow” tyre.
- The snow tyre definition is amended to clarify that snow tyres are suitable not only in snow conditions but also on mud.
- The proposal clarifies the application of the suffix M/C.
Q1What changed26 changes
Definition of “snow tyre” (para. 2.33.)
In the definition of “snow tyre” (para. 2.33.), “tread pattern and whose structure are” is now “tread pattern, tread compound or construction is”. The performance better than that of a normal tyre is now “in mud and/or snow conditions”, in place of “in mud and fresh or melting snow”. The ability of the tyre is now to “initiate and control vehicle motion”, in place of “initiate or maintain vehicle motion”.
Names of the categories of use (para. 2.1., subparagraph (c)) and new definition of “special tyre” (para. 2.40.)
New paragraph 2.40. defines “special tyre” as a tyre intended for mixed use both on- and off-road or for other special duty. It also says that these tyres are primarily designed to initiate and control the vehicle motion in off-road conditions. In paragraph 2.1., subparagraph (c), the categories of use are now named “normal tyre”, “snow tyre”, “moped tyre”, “all terrain tyre (AT)” and “special tyre”. Before, the names were “normal”, “snow”, “moped”, “all terrain (AT)” and “special”.
“M+S” inscription for special tyres (paras. 3.1.9. and 4.1.3.1.)
Paragraph 3.1.9. gives the inscription “M+S” or “M.S” or “M&S” if the tyre is classified in the category of use “snow tyre”. For a “special tyre”, the inscription applies when the tyre manufacturer declares at paragraph 4.1.3. that the tyre complies also with paragraph 2.33. Paragraph 2.33. is the definition of “snow tyre”. Before this supplement, paragraph 3.1.9. gave the inscription “in the case of a snow tyre”. The text now also says that “M+S” or “M.S” or “M&S” means “Mud and Snow”. New paragraph 4.1.3.1. adds, for the tyres in the category of use “special tyre”, “those which may bear the inscription M+S or M.S or M&S”.
Suffix “M/C” (para. 2.20.6.)
The suffix “M/C” is for tyres intended to be fitted on rims designed for motorcycles. It is mandatory for tyres having a nominal rim diameter equivalent to code 13 (330 mm) or above. It is now optional for tyres with nominal rim diameter equivalent to code 12 (305 mm) or below, in place of “for tyre sizes listed in Annex 5”. New text says that tyres not intended to be fitted on rims designed for motorcycles must not be marked with M/C.
Annex 5 tables: “Tyre size designation” heading and new “M/C” note
In Annex 5, Tables 1, 1a, 2, 3, 4, 6 and 7, the heading of the leftmost column is now “Tyre size designation*” in place of “Tyre size”. In Tables 5 and 8, the heading is now “Tyre size designation”. A new note follows each of Tables 1, 1a, 2, 3, 4, 6 and 7. Under the note, if the suffix “M/C” is not already part of the tyre size designation, it may be added optionally as part of it. This is recommended for tyres having a nominal rim diameter equivalent to code 13 (330 mm) or above.
Overall width measurement (Annex 6, paragraph 4.)
In Annex 6, paragraph 4., the words “by calliper” are removed: the overall width is measured at six equally spaced points. The text still takes account of the thickness of the protective ribs or bands, and the highest measurement is taken as the overall width.
Q2Why it changed
- Proposed by
- Experts from the European Tyre and Rim Technical Organization
- Working party
- GRBP, 77th session (February 2023)
Reasons
Before this supplement, the Regulation did not consider the case of a “special tyre” that can also fulfil the definition of a “snow” tyre. For this case, the proposal is that the tyre has to be marked with M+S or M.S or M&S if the tyre manufacturer declares it. The tyre stays in the category of use “special tyre”. The same provision has already been introduced in UN Regulations No. 30 and 54.
Sources (3)
“The current UN Regulation No. 75 does not consider the case of a "special tyre" that can also fulfil the definition of a "snow" tyre.”
“For this case it is proposed that, if declared by the tyre manufacturer, the tyre has to be marked with the inscription M+S or M.S or M&S while remaining in the category of use "special tyre".”
“The same provision has been already introduced in UN Regulations No. 30 and 54.”
The definition of “special tyre” is added because it was missing.
Source
“The definition of "special tyre" is added, as it is currently missing.”
The definition of “snow tyre” is amended to clarify that snow tyres are suitable not only for use in snow conditions but also on mud. The term “maintain vehicle motion” (keeping the vehicle speed and direction of movement constant) is replaced by the more general concept of “controlling vehicle motion”. This concept also includes being able to change the vehicle speed and direction of movement as intended.
Sources (3)
“The definition of "snow tyre" is amended to clarify that "snow tyres" are not only suitable for the use in snow conditions but also on mud”
“by replacing the term "maintain vehicle motion" (i.e. keeping the vehicle speed and direction of movement constant) by a more general concept of "controlling vehicle motion"”
“(i.e. also being able to change the vehicle speed and direction of movement as intended)”
The proposal removes the words “by calliper”, which fix a technical limitation, to explicitly allow other technical measurement solutions of the tyre overall width. The proposal says that the removal of this technical limitation would be advisable, following the principle of not stopping the technical innovations.
Sources (2)
“It is proposed to explicitly allow other technical measurement solutions of the tyre overall width by removing the words “by calliper” which fix a technical limitation.”
“The removal of this technical limitation would be advisable following the principle of not stopping the technical innovations.”
Editorial corrections make the categories of use consistent throughout the text and correct the headings in the tables in Annex 5. The proposal also clarifies the application of the suffix M/C.
Sources (2)
“Editorial corrections are introduced to ensure that the categories of use are used consistently throughout the text and to correct the headings in the tables in Annex 5.”
“The application of the suffix M/C is clarified.”
Document trail
- 2022-11ProposalECE/TRANS/WP.29/GRBP/2023/7Proposal by the experts from the European Tyre and Rim Technical Organization
- —Amended in sessionGRBP-77-21Proposal to amend ECE/TRANS/WP.29/GRBP/2023/7, transmitted by the experts of the European Tyre and Rim Technical Organisation
- —Working party adoptsECE/TRANS/WP.29/GRBP/75Session report, para. 15
- 2023-04Sent to WP.29ECE/TRANS/WP.29/2023/74Text that GRBP sent to WP.29 and AC.1
- 2023-06WP.29 adoptsECE/TRANS/WP.29/1173Adopted at the 190th session (session report, para. 165)
- 2024-01-05In forceC.N.14.2024.TREATIES-XI.B.16.75UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- To mark a special tyre “M+S”, “M.S” or “M&S”, declare at paragraph 4.1.3. that it also complies with paragraph 2.33.
Technical service / Approval authority
- Be ready to check special tyres marked “M+S”, “M.S” or “M&S” against the declaration at paragraph 4.1.3.
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ⓘ This report gives advice only. It is not legal or type-approval advice.