UN R109 Supplement 2 (01 series) · UNECE Regulation No. 109 (ECE R109) — Uniform provisions concerning the approval for the production of retreaded pneumatic tyres for commercial vehicles and their trailers.
UN R109 — Supplement 2 to the 01 series of amendments
Supplement 1 → 2
- What changed
- Paragraph 2.59. is deleted, and paragraph 2.4. now defines “Material supplier” in place of “Material manufacturer / material supplier”.
- Paragraphs 4.1.5.3.2.1., 4.1.5.3.2.2. and 4.1.5.3.2.3. are deleted, and paragraph 4.1.5.3.2. has one example table for the list of tyres for use in severe snow conditions.
- Paragraph 6.4.4.1. now covers retreaded tyres type approved pursuant to UN Regulation No. 172, and new paragraph 6.4.4.2. covers retreaded tyres categorized as “special use tyres”.
- Why
- The definition in paragraph 2.59. is too restrictive, because not all retreaded tyres from type-approved retreading units are type-approved pursuant to UN Regulation No. 172.
- The definition in paragraph 2.4. describes the material supplier and not the material manufacturer.
- The cases in paragraphs 4.1.5.3.2.1., 4.1.5.3.2.2. and 4.1.5.3.2.3. are already handled in UN Regulation No. 172.
Q1What changed61 changes
Tread supplier and material supplier (paras. 2.4., 2.59., 6.3.3., 6.3.7., 6.4.1., 6.4.4., 6.4.5. and 6.4.6.)
Paragraph 2.59. is deleted. It defined the “Supplier of the tread used for retreading process”. Paragraph 2.4. now defines “Material supplier” in place of “Material manufacturer / material supplier”. Paragraphs 6.3.3., 6.3.7., 6.4.1., 6.4.4., 6.4.5. and 6.4.6. now refer to the “material supplier”. Before, they referred to the manufacturer of the material, alone or as an alternative to the supplier. The former paragraphs 2.60., 2.61. and 2.61.1. are now paragraphs 2.59., 2.60. and 2.60.1.
Retreader and tyre manufacturer wording (paras. 3.2.8. and 3.6., Annex 7, para. 2.3.2.)
Paragraph 3.2.8. now lists the inscription M+S or M.S. or M&S, and the inscription MS is deleted. This applies if the tyre is classified in the category of use “snow tyre”. It also applies to a “special use tyre” declared as complying also with the definition given in paragraph 2.8.3. The retreader, in place of the tyre manufacturer, now makes this declaration at paragraph 4.1.5.3.1. Paragraph 3.6. now says “original tyre manufacturer's specifications” in place of “original manufacturer's specifications”. In Annex 7, paragraph 2.3.2., a higher test room temperature now needs the retreader's agreement, in place of the tyre manufacturer or retreader.
List of tyres for use in severe snow conditions (para. 4.1.5.3.2.)
Paragraph 4.1.5.3.2. now has one example table for the list of tyres classified as tyre for use in severe snow conditions and/or as traction tyre. The list must clearly identify the tyres to make the relevant link with the list(s) quoted in paragraph 6.4.4.1. b). The example table shows UN Regulation No. 172 approval numbers (TA) by tyre size designation and by retreader tread pattern (TPR). Paragraphs 4.1.5.3.2.1., 4.1.5.3.2.2. and 4.1.5.3.2.3. are deleted, with their example tables and notes. Before, these paragraphs set out the list for the retreaded tyres covered by paragraphs 6.4.4.1., 6.4.4.2. and 6.4.4.3., one case each.
Information on the treads used for retreading process (paras. 6.4.4.1., 6.4.4.2. and 6.4.4.3.)
Paragraph 6.4.4.1. now covers retreaded tyres type approved pursuant to UN Regulation No. 172. Before, it covered such tyres produced by using pre-cured tread or mould cure process with the same tread pattern not covered by paragraph 6.4.4.2. The material supplier(s) of the tread(s) now give the listed documents, in place of the manufacturer(s) or the supplier(s) of the tread(s). The former paragraphs 6.4.4.2. and 6.4.4.3. are deleted, and the former paragraph 6.4.4.4. is now paragraph 6.4.4.3. New paragraph 6.4.4.2. applies to retreaded tyres categorized as “special use tyres”. The retreader must make sure the supplier(s) of the tread(s) give the value of tread depth and void to fill ratio pertinent to each tread.
Tyre overall width and notes on dimensions (paras. 6.5.4., 7.1.4. and 7.1.4.2., Annex 5)
The notes (a) and (b) of paragraph 6.5.4. are deleted. In Annex 5, the note on the 1.5 per cent limit now refers to paragraph 7.1. in place of paragraph 6.5.4. The sentence on the 8 mm limit for retreaded radial tyres with an ASP now starts with “Notwithstanding the above”. Paragraph 7.1.4. is now headed “Tyre overall width specifications” in place of “Section width specifications”. Paragraph 7.1.4.2. now starts with “Except for the cases defined in paragraphs 7.1.4.3. and 7.1.4.4.”.
Outer diameter of snow tyres and its measurement (para. 7.1.5.2., Annex 6, para. 5.)
In paragraph 7.1.5.2., the outer diameter of tyres of the category of use “snow tyre” must not exceed Dmax,snow = 1.01 • Dmax. This value is rounded to the nearest mm, and Dmax is the maximum outer diameter established for normal use tyres in conformity with the above. Before, for snow tyres the maximum outer diameter (Dmax) calculated in paragraph 7.1.5.1. could be exceeded by not more than 1 per cent. In Annex 6, paragraph 5., the outer diameter is determined by dividing the measured maximum circumference of the inflated tyre by π (rounded to 3.1416). Before, it was calculated from a measurement of the maximum circumference of the inflated tyre.
Other text changes (para. 9., Annex 1)
Paragraph 9. now refers to Schedule 1 of the Agreement, in place of Appendix 2, for the conformity of production procedures. In the Annex 1 communication, the “Extension No.” entry is deleted from the “Approval No.” line.
Q2Why it changed
- Proposed by
- Experts from the European Tyre and Rim Technical Organization
- Working party
- GRBP, 83rd session (February 2026)
Reasons
The definition of the “Supplier of the tread used for retreading process” in paragraph 2.59. is too restrictive. Not all retreaded tyres produced by retreading units type-approved pursuant to this Regulation are type-approved pursuant to UN Regulation No. 172. The definition of material supplier in paragraph 2.4. covers also the supplier of tread used for producing those type-approved tyres. This definition describes the material supplier and not the material manufacturer. For this reason, the proposal also cancels the references to the material manufacturer as an alternative to the material supplier.
Sources (4)
“is too restrictive because not all the retreaded tyres produced by retreading units type-approved pursuant to this regulation are type-approved pursuant to UN Regulation No. 172”
“covers also the supplier of tread used for producing retreaded tyres type-approved pursuant to UN Regulation No 172.”
“because the definition given in this paragraph describe this market operator and not the material manufacturer.”
“it is also proposed to cancel the reference to the material manufacturer in all the paragraphs in which this market operator is referred as an alternative to the material supplier.”
The proposal simplifies the list of tyres classified as tyre for use in severe snow conditions and/or as traction tyre, because the lists are redundant. The cases in paragraphs 4.1.5.3.2.1., 4.1.5.3.2.2. and 4.1.5.3.2.3. are already handled in UN Regulation No. 172. A simple list with the UN Regulation No. 172 type approval number, the size and the retreader's trade description/commercial name covers all the needed information.
Sources (3)
“It is proposed to simplify the list of tyres classified as tyre for use in severe snow conditions and/or as traction tyre to be submitted at the application for approval, because they are redundant.”
“In fact, the various cases currently specified in paragraphs 4.1.5.3.2.1., 4.1.5.3.2.2. and 4.1.5.3.2.3. are already handled in UN Regulation No. 172.”
“a simple list reporting just the type approval number of UN Regulation No. 172 associated to the size and the trade description/commercial name given by the retreader to the retreaded tyre cover all the needed information.”
A new paragraph clarifies that suppliers of tread material for retreading special use tyres must give the retreader its void to fill ratio.
Source
“It is proposed to introduce a paragraph clarifying that the supplier of tread material dedicated to the retreading of tyres categorized as special use tyres shall provide to the retreader the void to fill ratio pertinent to such tread material.”
Paragraph 7.1.5.2. is aligned to paragraph 6.1.5.4. of UN Regulation No. 54. Section 9 referred to Appendix 2 of the 1958 Agreement, but the conformity of production procedures are in Schedule 1 of that Agreement. Based on Revision 3 of the Agreement, the extension number is already included in the approval number.
Sources (3)
“Paragraph 7.1.5.2. is aligned to paragraph 6.1.5.4. of UN Regulation No. 54.”
“The first paragraph of section 9 refers to Appendix 2 of the 1958 Agreement. However, the Conformity of production procedures are contained in Schedule 1 of that Agreement.”
“Based on Revision 3 of the Agreement, the extension number is already included in the approval number.”
Proposer's reason (informal document GRBP-83-22-Rev.2)
The notes (a) and (b) in paragraph 6.5.4. are not correct and misleading, so the proposal deletes them. The provisions in paragraph 7.1.4.2. are only applicable to tyres without ASP. In Annex 5, a wrong reference to paragraph 6.5.4. is corrected. Annex 5 must say that the previous paragraph is not valid for tyres with ASP, because the last paragraph specifies different requirements. Annex 6, paragraph 5. is reworded to clarify how the outer diameter is calculated. The value of pi is specified in line with recent changes in UN Regulation No. 30.
Submitted by Experts of ETRTO. Working party adoption: ECE/TRANS/WP.29/GRBP/83, para. 20.
Sources (6)
“The notes (a) and (b) in paragraph 6.5.4. are not correct and misleading. Therefore, it is proposed to delete them.”
“The provisions reported in paragraph 7.1.4.2. are only applicable to tyres without ASP.”
“In Annex 5, a wrong reference to paragraph 6.5.4. is corrected.”
“the last paragraph specifies different requirements than the previous paragraph. Therefore, it needs to be indicated that for tyres with ASP, the previous paragraph is not valid.”
“Annex 6, paragraph 5. is reworded to clarify how the outer diameter shall be calculated.”
“In line with recent changes in UN Regulation 30, it is proposed to specify the value of pi.”
Document trail
- 2025-11ProposalECE/TRANS/WP.29/GRBP/2026/12Proposal by the experts from the European Tyre and Rim Technical Organization
- —RevisedGRBP-83-21-Rev.2Proposal to replace GRBP/2026/12, transmitted by the experts of ETRTO
- —Amended in sessionGRBP-83-22-Rev.2Expanded version of the amendments to GRBP/2026/12, transmitted by the experts of ETRTO
- —Working party adoptsECE/TRANS/WP.29/GRBP/83Session report, para. 20: GRBP adopted GRBP-83-22-Rev.2
- 2026-04Sent to WP.29ECE/TRANS/WP.29/2026/94Text that GRBP sent to WP.29 and AC.1
- 2026-06-24WP.29 adoptsECE/TRANS/WP.29/1192Adopted at the 199th session (session report, para. 103)
- PendingIn forceDate not yet known
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- Update your list of tyres classified as tyre for use in severe snow conditions and/or as traction tyre.
- For tyres type approved pursuant to UN Regulation No. 172, make sure tread material suppliers provide the paragraph 6.4.4.1. documents.
- Check snow tyre outer diameter: at most 1.01 • Dmax of normal use tyres, rounded to the nearest mm.
Technical service / Approval authority
- Check snow tyre outer diameters against 1.01 • Dmax of normal use tyres, rounded to the nearest mm.
- When measuring to Annex 6, divide the maximum circumference of the inflated tyre by π (rounded to 3.1416).
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ⓘ This report gives advice only. It is not legal or type-approval advice.