On the Definition of Narrow-track Wheeled Agricultural Tractors

Abstract

The narrow-track agricultural tractor has been defined in the field of application of International Organisation for Standardisation (ISO), European Community (EC) and Organisation for Economic Co-operation and Development (OECD) Standards. The field of application does not allow narrow-track tractors to be fitted with tyres set at a minimum track width wider than 1150 mm, enabling tyres to be fitted with adjustable track width which, still having a minimum track width of not more than 1150 mm, can be set at greater track widths during normal operation of the tractor. Tests showed that tyre types which can be fitted on a narrow-track tractor and always determine a tractor track width wider than 1150 mm, have the same behaviour as the tyre types currently allowed in the field of application of the Standards, when set at the allowed maximum track widths. In the light of these results, it is recommended to define a narrow-track tractor as an agricultural tractor that, when fitted with tyres of the greatest diameter indicated by the manufacturer, has a minimum track width of not more than 1150 mm.