Before 1973, the usual production wheel consisted of a hefty hub, 36 or 40 steel wire spokes, and a steel rim. For racing, the steel rim became aluminum, a metal whose density is only 36 percent that of steel. English racer Peter Williams had experimented with cast "artillery wheels" on his Matchless G-50 in the late '60s, and in 1973, Elliott Morris produced his seven-spoke cast magnesium racing wheels. Classic-era-rider Phil Reed hand-carried a set of Morris mags to MV Agusta. Soon there were also Shelby-Dowd mags, Campagnolo mags, Dymags—lots of choices. Rims grew in width from the 2.13 inches of an old-tech WM-3 to rear widths as large as 6.5 inches, but wheels became ever lighter. Today, forging magnesium wheels, rather than casting them, gives greater fatigue strength even in a much lighter product, shaving further weight. Such wheels, in hands accustomed to the 50-pound car wheels of the '70s, feel like paper.