At the end of the Fifties, a number of craftsmen began to build chassis, attempting to reproduce the karts that were arriving from the United States. That was what set Umberto Sala, whose nickname is Birel, on the road to lasting success. After just a few years, Sala's karts stood out for their technical content and personality and they have become so successful that in the 40 years since the Birel company was formed, its karts have won 25 world championships and numerous European and national titles. Drivers destined for brilliant motor racing careers won with chassis built at Birel's headquarters at Lissone. Men like Riccardo Patrese, Keke Rosberg, Stefano Modena, Emanuele Pirro, and current stars of Formula One, like Mika Hakkinen and Juan Pablo Montoya.