Road Racing FIM Sidecar World Championship ... - Spelregels

5) Tyre surface tread pattern
The surface of the tyre can be smooth (i.e. without tread grooves) or
treaded.
The tread pattern is unrestricted.
The tread pattern shall be made by a manufacturer when producing the
tyre.
Additional tread grooves, cuts, etc., are allowed provided that they are
made by a tyre manufacturer or a person duly authorised by a tyre
manufacturer by means of special purpose-built equipment.
Thus, subsequently modified tyres shall bear the distinguishing mark or
stamp of the manufacturer. This stamp shall be placed near to the
manufacturer's mark.
The choice of a certain type of tread pattern is left entirely up to the
individual rider.
The use of slick tyres will also be at the discretion of the rider. If conditions
should become problematic however, he shall take into account the
recommendations of the Technical Stewards and if need be, of the
appropriate representative of the tyre manufacturers.
As a safe minimum, the depth of the tyre tread over the whole pattern at
pre-race control shall be at least 2.5 mm.
Tyres which at the preliminary examination have a tread depth of less than
1.5 mm are considered as non-treaded tyres and the restrictions applying
to slick tyres will then apply to them.
The surface of a slick tyre shall contain three or more hollows at 120°
intervals or less, indicating the limit of wear on the centre and shoulder
areas of the tyre. When at least 2 of these indicator hollows become worn
on different parts of the periphery, the tyre shall no longer be used.
2.3.7 The minimum distance between the surface of the tyre (at its
largest point) and any fixed parts of a motorcycle is shown in
Table 1 .
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