In the latter half of the 1970s, Shimano began product development based on ergonomics. In the meantime, the idea of making the chainring non-circular rather than perfectly round was proposed in order to achieve more efficient pedaling in response to the natural foot motion of humans. In 1983, a new front chainwheel following this concept named BIOPACE was incorporated into several series, including SHIMANO 600 EX for road bikes and SHIMANO DEORE XT and for mountain bikes, respectively. It was with SUPER PACE that Shimano appealed to the Japanese market by optimizing BIOPACE for sports bikes in Japan. For triple chainrings, optimum different shapes were designed by computer, offering ride comfort for all riding conditions. This approach based on ergonomics had a significant impact on subsequent product development at Shimano.