In the latter half of the 1990s, when mountain bike downhill races boomed, Shimano was engaged in the development of an unprecedented shifting system. Since in the downhill, in which riders could afford to lose no time, quick shifting was significantly important, Shimano thought of components using pneumatic pressure, and developed SHIMANO AIRLINES. The ultimate operability dedicated to downhill bikes was achieved by separating the roles of shifting operation between the right and the left levers: left for upshifting and right for downshifting. Rides on bikes equipped with the prototypes competed at the DH World Cup events in 1999. Testing at real races attracted tremendous interest at that time. SHIMANO AIRLINES was a limited-production model with a serial number inscribed on the shift lever and its scarcity became a factor that further attracted general users. Although this product was designed only for downhill racing, it demonstrated Shimano’s attitude toward manufacturing, characterized by an untiring quest for technological innovation to improve product usability.