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04/03/2013
THE INS AND OUTS OF HOMOLOGATION

RETREADED TYRES
Seven years ago, on 13 September 2006, the application of regulations ECE 108 and ECE 109 for retreaded tyres was made compulsory by European Union Directive 2006/443. The following is an outline of the rules of homologation and some of the pitfalls to avoid when buying retreads

Luca Ricci

WITH THE CURRENT economic crisis, the spotlight is again shining on retreading, a “tyre service” that increasing numbers of consumers use to optimize running costs.
AIRP emphasizes that saving is effective only if quality products are bought from homologated retreading plants that scrupulously observe the regulations.
In fact homologation refers to the retreading plant and it is issued following successful tests on production samples by the authority responsible for verifying the manufacturing process. This is the first element to look out for: homologation is strictly associated with the manufacturing site and cannot be transferred when a plant is bought or sold.
Brands are also associated with the manufacturing plant. When requesting plant homologation, the retreading firm must declare all the brands it handles.
The homologation request must also include the load index and maximum speed rating of the retreaded tyres in accordance with the so-called “worst case” principle. This is because the tyres undergo a testing program that corresponds to the load index and speed rating indicated. The tests for the first homologation must be repeated annually.
The manufacturing and material application system must also be declared: if a firm has been homologated for hot retreading but wants to make pre-cured treads as well, the homologation certificate must be updated. The retreading firm must also declare the range, usage category, structure and if it makes winter tyres, and advise the relevant homologation authority of the amendments.
When approval has been obtained, the retreading firm can apply the marking shown below.


The above mark of approval on a retreaded tyre indicates that the retreading centre was approved in Holland (E4) with approval number 109R002439 and complies with the original version (00) of regulation ECE 109.
In addition to the mark of approval, other markings must also be shown on both walls of the tyre or on the external wall of asymmetric tyres.
Firstly, the retreading firm’s trade name  must be shown. Anonymous tyres are not permitted. It must be clearly indicated that the tyre is a retread: since 1 January 1999 the only marking permitted is “RETREAD”. On the request of the retreading firm, this word can be accompanied by its translation in other languages. The date of manufacture must be shown on one wall of the tyre; this is a four-figure code in which the first two figures indicate the week number and the last two the year. The code can indicate the week of production plus another three weeks. For example, 2503 means the tyre was retreaded in week 25, 26, 27 or 28 of the year 2003.
There are other markings that are similar to those on new tyres, such as the load index and speed rating, the word “TUBELESS”, the symbols M+S, MS, M.S. or M&S for snow tyres. Then there are the indications of size, the structure, where “D” or no indication of rim diameter stands for Diagonal, “R” stands for Radial and “B” and “BIAS BELTED” indicate tyres with belts.
It is very important to verify the presence of the inverted omega or the word “REGROOVABLE”, which indicates that the tyre can be re-grooved.


There are other types of markings for special uses or particular situations.
It should be emphasized that if the original manufacturer’s specifications are still legible after retreading, these are understood to be the specifications of the retreading firm. However, if the original specifications are no longer valid after retreading, they must be eliminated. An important point to remember is that a casing cannot be retreaded if it does not have the “E” or “e” marking of the original homologation.
When buying retreaded tyres it is important to carry out these simple checks. It can never be emphasized enough that retreads optimize tyre management costs, provided that quality products from homologated plants are used.

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