This just in from the AMA. This ruling means any and all forms of traction control are are legal in FX and Superbike, while only traction control systems that use OEM sensors are legal in Supersport and Superstock.
COMPETITION BULLETIN
TO: All Road Race Licensed Riders and Season Credential Holders
FROM: Kevin Crowther, Director of Technical Development
DATE: July 17, 2006
SUBJECT:
Effective immediately replace rule E.23.A pg 36 with:
a. For Superstock and Supersport, any form of engine control system that can actively change the performance/acceleration of the engine using input from any sensors that are not OEM on the motorcycle, to create a situation of better traction at the rear wheel at any time while the motorcycle is being ridden is prohibited.