Do not reinvent the wheel!

摘要

Standards related to wheels for cars and trucks have been worked on since 1972. ISO/TC 22/SC 19, Road Wheels was formed in 1972 and has been active ever since. The scope of the subcommittee is standardization of wheels and wheel mounting systems with particular reference to nomenclature, interchangeability, and test procedures. There are seven standards issued on wheels and three more at the DIS ballot stage. Why do we need wheel standards since wheels have been around for over 2000 years? The first standards established evaluation methods for fatigue and kerb impact properties so that global vehicle manufacturers could evaluate wheels from different wheel manufacturers and still maintain the safety required. The performance for each wheel is not specified since the application and usage is different for different type of vehicles and in various areas of the world. The next standard defined nomenclature in English, French and German so that all users could communicate with the same concepts. The standard also covers marking of the wheels to match up with tyres and let users know what size they are using to allow proper fit to the vehicle and tyre. Since commercial vehicles are more global in usage than the automobiles, standards for these wheels include the bolt patterns used to attach the wheel to the vehicle and the fasteners, dimensions and strength properties. These standards were created when there were a wide variety of bolt patterns and fasteners in use. By standardizing these dimensions, the new wheels have migrated to the ISO standards. TC 22/SC 19 is still working on new standards related to the uniformity of wheels for ride control, balance weight standards for clip on weights, fasteners strength properties for passenger car wheel nut seats, and maintenance for wheels. The last standard will define conditions for a wheel to be removed from service if the wheel will no longer safely perform its functions. The standard also defines the causes for these conditions so that users can replace the wheel and fix the conditions that caused the problem with the original wheel. All of this work is done so that everyone does not have to reinvent the wheel.