From a press release issued by AMA Pro Racing:

2003 AMA U.S. Superbike Championship Proposed Rule Changes

The following proposals are designed for sweeping improvement of the AMA
Chevy Trucks U.S. Superbike Championship beginning with the 2003 season.
Input from the AMA Pro Road Race Advisory Board, teams, riders, promoters,
media and AMA Pro Racing staff was utilized in creating these proposals.
All aspects of the series, from competition to marketing, were reviewed
and considered.

AMA Pro Racing road race competitors and credential holders have the
opportunity to express their opinions and offer suggestions regarding
these proposals. The changes mainly cover general technical aspects of
Superbike, Supersport and Superstock. Any other changes to the 2003 road
racing rules will be proposed in the fall.

Road race competitors and credential holders are invited to submit
comments by mail, fax or through the RIDERS ONLY section of
amaproracing.com, at http://www.amaproracing.com/ridersonly. The comment
period starts Thursday, June 27, 2002, and ends Friday, July 26, 2002.


03-1. Superbike – 1000cc three- and four-cylinder motorcycles will be permitted for competition that meets the following criteria. 750cc fours and 1000cc twins would continue under the current Superbike rules:

1. 1000cc threes and fours will be subject to all current Superbike rules concerning frames, suspension, wheels, brakes and bodywork.

2. Weight: 1000cc three-cylinder machines, 360 lbs.
1000cc four-cylinder machines, 370 lbs.

3. Engines
– Cylinder heads: Porting and machining will be permitted.
– Stock valves and retainers must be utilized.
– Aftermarket cams permitted.
– Cylinders, engine cases and connecting rods will be subject to current Superbike rules.
– Crankshaft: Stock except for necessary balancing.
– Stock pistons, piston pins and rings must be utilized.
– Transmissions must retain stock ratios.
– Ignition systems will be subject to current Supersport rules.
– Charging systems and starters will not be required.
– Fuel injection, carburetors and air boxes will be subject to current Supersport rules except air filters and emissions plumbing will not be required.
– Exhaust systems will be subject to current Superbike rules.
– Homologation would require motorcycles to be originally U.S. street-legal.



03-2. Supersport

1. 750cc twin-cylinder motorcycles will be permitted for competition provided current homologation procedures are followed by manufacturers.

2. Machining of gasket surfaces of cylinder heads, cylinders or engine cases for increased compression only will be permitted. The increased compression may help to balance the competition between brands and will eliminate the need to inspect deck heights.


03-3. Superstock

1. Machining of gasket surfaces of cylinder heads, cylinders or engine cases for increased compression only will be permitted. The
increased compression may help to balance the competition between brands and will eliminate the need to inspect deck heights.