to cross-country skis, simply shorter and wider. Experiments with deeper sidecuts had been carried out with limited success, but the much deeper sidecuts of snowboards led to further experiments. In 1993 the Elan SCX introduced a radical sidecut design that dramatically improved performance of alpine skis. Other companies quickly followed the Elan SCX design, and it was realized in retrospect that "It turns out that everything we thought we knew for forty years was wrong." Since then, "shaped" skis have dominated alpine ski design. Early ski designs Early modern skis, made in Telemark, Norway by Sondre Norheim, were handmade from a single piece of hardwood and featured a relatively modest sidecut of about 4 to 5 mm. After this, advances were made in materials and construction, but in terms of shape, skis of the 1970s were largely identical to those of the 1800s. In 1939, Dick Durrance ordered a custom ski from Thor Groswold's factory in Denver with a 7 mm sidecut, and this became a new standard for slalom skis. During the winter of 1948/49, Jerry Hiatt and Thor's son Jerry decided to experiment with even bigger sidecuts. Taking a pair of the company's standard hickory Rocket skis, they cut away wood until they produced a 15 mm sidecut. When they tried them out, they found they turned quite easily in a series of rounded turns. But this was considered poor form in the era of the stem Christie, where good form was a series of sharp J-shaped turns, and the two abandoned the design. In any case, wooden skis of this era did not provide the torsional stiffness required to benefit from the performance sidecut now adds. Hiatt and Groswold's experiment required such a deep sidecut that the waist had little vertical stiffness, another problem for the design. Snowboards A radical change in design did not occur until the mid-1970s introduction of the first modern snowboards. With no previous designs to set the mould, snowboard designers had to experiment to find the right layout. The 1975 Burton Backhill had a 17 mm sidecut, giving the board a very short turning radius. The Backhill was extremely low-tech in comparison to contemporary ski designs, consisting largely of a sheet of plywood. A contemporary ski's torsion box design greatly improved torsional stiffness and would allow even greater sidecut to be effective. But in spite of the snowboard demonstrating that modern skis