One day in 1917 Rudolph Lettner was preparing for a steep, icy run just south of Salzburg, Austria. To his dismay, the worn-down edges of his hickory skis wouldn’t hold an edge. He elected to slide down, and found that he could only control his momentum by digging in the metal tip of his ski pole. That experience hatched the idea for a metal-edged ski. After nearly a decade of tinkering, Lettner found that he could preserve a ski’s flex by screwing small steel edge segments to the wood. He built a ski that could cut through snow for tighter, faster turns. Though he patented his design in 1926, the market was soon flush with similar models, and by the early 1930s, metal-edged skis were ubiquitous.