Costly (to the OEMs) updates to the 600s arrive every two years in a never-ending quest to one-up their rivals. And it's for these reasons why the ZX-6R is so redoubtable. Kawasaki has built a motor that handily out-guns its 600cc rivals, but just as impressive is a 22-lb lighter machine that handles like a champ, aided by Showa's fabulous new Big Piston Fork. Doubly impressive is that the Ninja took top honors on both the street and track – no mean feat. Triumph's Daytona 675 gives the ZX a run for its money, but among four-cylinder middleweights, the nasty and nimble Ninja stands clearly at the top of this ultra-competitive heap.
