5. Performance
The required performances described in 5.1, 5.2, 5.3, and 5.4 were determined on the basis of the “Technical Standards for Light Alloy Disc Wheels for Motorcycles” (a circular notice of Ministry of Transport, Jisha No.1 January 25,1978) (hereafter referred to as “Motorcycle Technical Standards”), and in accordance with the expressions adopted in JASO C 603. Further, the criteria on the joined portions were also added, considering the case of the composite construction type wheels.
As for the criteria on harmful cracks, it is desirable to employ the test procedures prescribed in JIS Z 2343 (Methods for Liquid Penetrant Testing and Classification of Indication) or the equivalent.
5.3 Impact Resistance
Although discussions were carried out concerning the effects of the striker weights upon the struck portions and the effects caused by the direct contact of striker weights upon the wheels, no provisions were established for them, because the striker weights rarely came in direct contact with the wheels.
5.5 Airtightness of Rims
For the airtightness of the rims, appropriate consideration was given so that such rims would be also applicable to tubeless tires, from the tendency of use of the light alloy wheels in future.