BS ISO 18106:2016 pdf download

BS ISO 18106:2016 pdf download.Passenger car, commercial vehicle, truck and bus tyres — Methods for measuring snow grip performance — Loaded new tyres
1 Scope
This International Standard specifies the method for measuring relative snow grip performance index of a candidate tyre compared to a reference, under loaded conditions for new tyres intended to be used on passenger car, commercial vehicle, truck and bus vehicles on a snow packed surface.
The methods developed here are meant to reduce the variability of the performance measurement. The use of the proper reference tyres is necessary to limit the variability of the testing method procedures.
This International Standard applies to all passenger car, commercial vehicle, truck and bus tyres.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4000-1, Passenger car tyres and rims (metric series)一Part 1: Tyres
ISO 4209-1, Truck and bus tyres and rims (metric series) – Part 1: Tyres
ASTM F1805, Standard Test Method for Single Wheel Driving Traction in a Straight Line on Snow- and Ice-Covered Surfaces
ASTM E1136, Standard Specification for P195/75R14 Radial Standard Reference Test Tire
ASTM F2870, Standard Specification for 315/70R22.5 154/150L Radial Truck Standard Reference Test Tire
ASTM F2871, Standard Specification for 245/70R19.5 136/134M Radial Truck Standard Reference Test Tire
ASTM F2872, Standard Specification for 225/75R16C 116/114S M+S Radial Light Truck Standard Reference Test Tire
4.1 Braking on snow method for passenger car tyres
4.1.1 General
Snow performance is based on a test method by which the mean fully developed deceleration in a braking test, of a candidate tyre is compared to that of a standard reference test tyre. The relative performance shall be indicated by a Snow Grip Index (SG).
4.1.2 Test course
The braking tests shall be done on a flat test surface of sufficient length and width, with a maximum 2 % gradient, covered with packed snow. The snow surface shall be composed of a hard packed snow base at least 3 cm thick and a surface layer of medium packed and prepared snow about 2 cm thick. The air temperature, measured about one meter above the ground, shall be between -2 °C and -15 °C; the snow temperature, measured at a depth of about one centimetre, shall be between -4 °C and -15 °C. It is recommended to avoid direct sunlight, large variations of sunlight or humidity, as well as wind. The snow compaction index measured according to ASTM F1805 by using a CTI penetrometer shall be between 75 and 85. The candidate tyre should be tested in the same slope and snow compaction condition as the reference tyre to avoid any advantage or disadvantage for the candidate tyre.