AMA Pro Racing and Kawasaki announced yesterday that the new 2013 ZX-6R with its oversize 636cc four-cylinder engine was homologated for competition use in the Daytona SportBike and Supersport classes. In order to even out the Kawasaki’s displacement advantage over other conventional four-cylinder machines, AMA Pro Racing gave the 2013 ZX-6R 636 a 20-pound weight penalty, with a minimum finish-line weight (“Minimum weight in the exact condition the machine finishes any competition activity—qualifying or race—without the addition of fluids or other items of any kind” according to the AMA Pro Racing rulebook) of 375 pounds, compared to 355 pounds for other four-cylinder 600s.
It should be noted, however, that the 20-pound weight penalty is subject to revision, depending on how the new ZX-6R 636 fares in competition. One of the more frequently referred to phrases in the AMA Pro Racing rulebook is that, “If it becomes apparent that one type or model of motorcycle gains an unfair performance advantage, AMA Pro Racing reserves at any time the right to implement restrictions including but not limited to adding or reducing weight to that type or model of motorcycle to restore competitive balance.” This was basically the case in 2011, when the Ducati 848 EVO V-twin started the season off by winning Daytona, and then dominating the first race at Infineon Raceway in California. After some race-by-race adjustments, the Ducati was finally given a minimum weight restriction of 375 pounds—ironically the same 20-pound weight penalty as the new Kawasaki, as the V-twin originally started off at the same 355-pound weight minimum as the four-cylinders.
The 2013 Kawasaki ZX-6R has also been approved for competition use by numerous club racing organizations, including various middleweight categories in WERA, CCS, AFM, MRA, CVMA, CMRA, and UtahSBA.