3. Types
Although some composite construction type wheels consisting of steel rims and light alloy spokes (or hubs) are sold on market, this Standard adopts only those with the rims made of light alloy, since the rim portion is important as a strength member of the wheel for motorcycles. It must be also noted that some of composite construction type motorcycle wheels are excluded from the Standard even though the rims are made of light alloy, because the structure to keep the strength is different from normal ones.