From AMA Pro Racing’s 2004 AMA Superbike Championship rulebook on www.amaproracing.com:
b. Swing arms
Stock swing arms must be utilized. The only modifications permitted are gusseting and attachment of stand mounts. 1000cc – 1350cc air-cooled twin-cylinder motorcycles are unrestricted.
See related post:
6/16/2004 Updated Post: AMA Pro Racing Changes Formula Xtreme Swingarm Rule Without Notice Or Comment
How The AMA Formula Xtreme Swingarm Rule Was Originally Worded In The 2004 Rulebook
How The AMA Formula Xtreme Swingarm Rule Was Originally Worded In The 2004 Rulebook
© 2004, Roadracing World Publishing, Inc.
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