UN R109 Supplement 12 (00 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 12 to the 00 series of amendments
Supplement 11 → 12
- What changed
- Annex 10, paragraphs 1.3., 2., 2.1. and 2.2. now refer to ASTM standard F1805-20 in place of ASTM standard F1805-06.
- New paragraph 2.3. of Annex 10 computes the snow grip index (SG) of a candidate tyre Tn as SG(Tn) = f ∙ TPI / 100. Here f = 0.987 when using SRTT16 as reference tyre per ASTM F1805-20.
- Paragraph 3.5.2. now covers the date of retreading as defined in paragraph 3.2.9., when it is not moulded. It must be applied not later than 5 working days after the completion of the retreading process at the facility concerned.
- Why
- The expert from France proposed to align the test procedures for retreaded tyres with the text adopted by WP.29 for UN Regulation No. 117 (ECE/TRANS/WP.29/2021/8).
- For paragraph 3.5.2., the ETRTO experts say their new proposal gives a more realistic approach for the operations flexibility that small retreaders need.
Q1What changed8 changes
ASTM standard F1805-20 for the traction test (Annex 10, paras. 1.3., 2., 2.1. and 2.2.)
Annex 10, paragraphs 1.3., 2., 2.1. and 2.2. now refer to ASTM standard F1805-20 in place of ASTM standard F1805-06. Paragraph 2. now uses the ASTM standard F1805-20 test procedure to assess snow performance through the traction performance index (TPI) on medium pack snow. Before, it used spin traction values on medium packed snow. Paragraph 2.2. adds that the SRTT16, when used as reference tyre, must be tested with a load of 531 kg at 240 kPa (cold).
Snow grip index of a candidate tyre (Annex 10, para. 2.3.)
New paragraph 2.3. says how to compute the snow grip index (SG) of a candidate tyre Tn: SG(Tn) = f ∙ TPI / 100. Here f = 0.987 when using SRTT16 as reference tyre per ASTM F1805-20, and TPI is the traction performance index as defined in ASTM F1805-20.
Date of retreading that is not moulded (para. 3.5.2.)
Paragraph 3.5.2. now covers the date of retreading as defined in paragraph 3.2.9., when it is not moulded. Such a date must be applied not later than 5 working days after the completion of the retreading process at the facility concerned. Before, paragraph 3.5.2. covered the date of manufacture, and the limit was not later than 24 hours after the tyre is removed from the mould.
Q2Why it changed
- Proposed by
- Expert from France; experts from the European Tyre and Rim Technical Organization
- Working party
- GRBP, 77th session (February 2023)
Reasons
The amendment is required to align the test procedures for retreaded tyres with the text adopted by WP.29 for UN Regulation No. 117. WP.29 adopted that text in ECE/TRANS/WP.29/2021/8.
Sources (3)
“This amendment to UN Regulation No. 109 is required in order to ensure that the test procedures for retreaded tyres are aligned with the text adopted by the World Forum for Harmonization of Vehicle Regulations (WP.29)”
“aligned with the text adopted by the World Forum for Harmonization of Vehicle Regulations (WP.29) in ECE/TRANS/WP.29/2021/8 for UN Regulation No. 117”
“The expert from France proposed aligning the test procedures in UN Regulation No. 109 with those in UN Regulation No. 117”
Proposer's reason (informal document GRBP-77-22)
Informal document GRBP-77-22 is aimed to replace working document GRBP/2023/10, as that document was not correctly addressing the issue. The new proposal for paragraph 3.5.2. gives a more realistic approach to cover the need of operations flexibility of small retreaders.
Submitted by Experts of the European Tyre and Rim Technical Organisation. Working party adoption: ECE/TRANS/WP.29/GRBP/75, para. 18.
Sources (2)
“This informal document is aimed to replace the working document GRBP/2023/10 as not correctly addressing the issue.”
“This new proposal is providing a more realistic approach for covering the need of operations flexibility of small retreaders.”
Document trail
- 2022-11ProposalECE/TRANS/WP.29/GRBP/2023/4Proposal by the expert from France
- 2022-11ProposalECE/TRANS/WP.29/GRBP/2023/10Proposal by the experts from the European Tyre and Rim Technical Organization
- —RevisedGRBP-77-22Proposal to replace GRBP/2023/10, transmitted by the experts of the European Tyre and Rim Technical Organisation
- —Working party adoptsECE/TRANS/WP.29/GRBP/75Session report, paras. 17 and 18
- 2023-04Sent to WP.29ECE/TRANS/WP.29/2023/75Text 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.26.2024.TREATIES-XI.B.16.109UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- Apply a non-moulded date of retreading (3.2.9.) not later than 5 working days after retreading ends at the facility concerned.
Technical service / Approval authority
- Check that the Annex 10 traction test uses ASTM F1805-20 and the traction performance index (TPI) on medium pack snow.
- Check that SRTT16, when used as reference tyre, is tested with a load of 531 kg at 240 kPa (cold).
- Check that SG(Tn) = f ∙ TPI / 100 is used, with f = 0.987 when using SRTT16 as reference tyre.
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ⓘ This report gives advice only. It is not legal or type-approval advice.