ISO 11795:2018/Amd 1:2022

Overview

ISO 11795:2018/Amd 1:2022 is an important international standard published by the International Organization for Standardization (ISO) that provides a detailed explanation of the rolling circumference index (RCI) and speed radius index (SRI) for agricultural tractor drive wheel tyres. This amendment updates the method of measuring tyre rolling circumference and introduces revised RCI values, ensuring uniformity and precision in tyre specification and performance evaluation.

The standard is applicable to agricultural tractor drive wheel tyres, addressing key parameters that affect tyre performance, speed calibration, and vehicle dynamics. By defining standardized measurement methods and index values for rolling circumference, ISO 11795:2018/Amd 1:2022 supports manufacturers, regulatory bodies, and farmers in achieving optimal tyre selection and tractor operation.

Key Topics

• Rolling Circumference Index (RCI):
  This index categorizes tyre rolling circumferences into standardized value ranges to facilitate consistent tyre size identification and performance assessment. The amendment provides an updated table of RCI values, including minimum, maximum, and target rolling circumference measurements in millimeters.

• Speed Radius Index (SRI):
  The SRI relates to the effective rolling radius of the tyre, critical for calculating vehicle speed, transmission settings, and in-field tractor operation efficiency.

• Rolling Circumference Measurement Method:
  The document outlines precise, repeatable methods for measuring the tyre rolling circumference - a vital factor influencing speedometer accuracy, ground speed monitoring, and fuel efficiency.

• Updated RCI Table:
  Amendment 1 revises the rolling circumference index values with clearly defined measurement ranges from RCI 0 to RCI 53, covering rolling circumferences from 495 mm up to 8,092 mm, supporting a wide spectrum of agricultural tractor tyre sizes.

Applications

• Agricultural Machinery Manufacturers:
  Use this standard to ensure tyre designs meet consistent rolling circumference standards, facilitating compatibility with tractor systems such as speedometers and traction control.

• Tractor Operators and Farmers:
  Enables accurate tyre selection based on rolling circumference indexes, helping optimize tractor speed calibration and minimizing wheel slip for improved fieldwork efficiency.

• Tyre Testing and Certification:
  Laboratories and regulatory agencies use the measurement methods and RCI values for tyre assessment, certification, and compliance checks aligned with globally recognized standards.

• Fleet and Equipment Maintenance:
  Maintenance teams can reference the standard to verify tyre dimensions and rolling parameters for safety, performance optimization, and replacement scheduling.

Related Standards

• ISO/TC 31 Series:
  ISO technical committee responsible for tyres, rims, and valves, producing related standards on agricultural tyres, rim dimensions, and tyre safety.

• ISO 4254 Series:
  Agricultural machinery safety standards that may reference tyre performance parameters for machine operation.

• ISO/IEC Directives, Part 1 & 2:
  Governing documents describing the development and editorial process of ISO standards, including conformity assessment principles.

Conclusion

ISO 11795:2018/Amd 1:2022 is essential for the agricultural industry, providing a unified reference for understanding and measuring tractor tyre rolling circumferences. This ensures better equipment compatibility, enhanced tractor performance, and improved operational safety. Incorporating this standard facilitates international consistency in agricultural tyre manufacturing, testing, and use-ultimately supporting sustainable and efficient farming practices.

For detailed information and access to the full standard, visit the ISO official website.