From next year the American superbike (AMA) series will run on broadly similar lines to the British domestic championship after officials finally settled on a framework to allow teams to run superstock-spec, 1000cc four-cylinder machines.
For more on this story don’t miss the October 23 issue of MCN.
However, the rules will allow teams that run 750cc four-cylinder WSB-spec bikes to increase the capacity to almost 800cc to keep them competitive. That option was vetoed in BSB by Ducati.
Other changes centre around the amount of tuning teams can do to the engines of the 1000cc fours. In BSB teams are allowed to vary the lift and duration of the camshafts for more power, but in the AMA series porting and polishing of the cylinders is permissible, as is cam duration, but not cam lift.
All machines in the series must increase their weight to a new minimum of 168kg (370lb) up from 162kg (355lb). Like BSB, teams running the 1000cc fours will be free to do so without restrictors in the air-box, contrary to the rules laid out for WSB teams in 2003.