SAE J2429_201509

This SAE Recommended Practice describes a test method for determination of heavy truck (Class VI, VII, and VIII) tire force and moment properties under free-rolling cornering conditions. The steady-state properties are acquired as functions of slip angle and normal force, which are changed incrementally using a sequence specified in this document. The data are suitable for use in vehicle dynamics modeling, comparative evaluations for research and development purposes, and manufacturing quality control. This document addresses two principal topics; a) the description of a hypothetical “Ideal Machine,” and b) a standard directly applicable to testing practices currently common to the industry. The references to the “Ideal Machine” are meant to provide a roadmap for the testing machine manufacturer, providing direction and goals for the next generation of testing capabilities. The ranges of parameters for the “Ideal Machine,” including those in Tables 2 and 3, are intended to represent minimal requirements to meet the full and complete data needs of the industry. The remaining documentation provides practical guidelines for the test engineer to ensure the integrity of data generated using current and conventional means. The original document made some assumptions regarding future work that have not been met. Additionally, the over-the-road test machine mentioned in the text has been decommissioned and is no longer available. Needs for corrections were found during the renewal process. The purpose of this revision is to implement these corrections and bring the document up to date in light of developments between 2004 and 2015.