Bicycle wheel some other fixed point may be used as a reference mark, however this is less accurate. At one end of each spoke is a specialized nut, called a nipple, which is used to connect the spoke to the rim and adjust the tension in the spoke. The nipple is usually located at the rim end of the spoke but on some wheels is at the hub end to move its weight closer to the axis of the wheel, reducing the moment of inertia. Until recently there were only two types of nipples: brass and aluminum (often referred to as "alloy").
Hubcap decorating one car with the wheel covers from another was common. Two very desirable wheel covers were those of the 1950 Cadillac (called the "Sombrero") and that of the 1953 to 1955 Oldsmobile, which resembled a huge, three-tined spinner. Aftermarket suppliers included the "Mooneyes" brand (named after the firm's founder Dean Moon) hubcaps and wheel covers that were some of the first independently offered for hot rods and custom cars. Another variant of the wheel cover, known also as "wheel shrouds" or "rim blanking", is that commonly associated with the German wheelmaking brand BBS since the 1970s. These are attached