Adjustable offset triple clamp solid model (upper & lower)



We developed these triple clamps to correct a severe handling issue induced by the installation of GSX-R1100 forks on an FXR with the standard GSX-R triple clamps. The GSX-R clamps have far too little offset, which creates excessive trail. These triple clamps reduce the trail to below the stock FXR's, have ±6mm of adjustment, and produce handling uncharacteristically good for a Harley-Davidson. Each set of bushings has a set of steering stops that goes with it, which, if the bushings are reversed, is also reversed (see lower clamp). We designed these stops to stop the fork tube on the same plane (rather than at the same steering angle) at full lock, regardless of which offset is chosen. This produces extra steering angle the more offset is used, so the minimum turning radius is always as small as possible. Additionally, the stops are designed so that the mounting bolt centerline is always as close to 90° to the striking surface as possible, insuring that both bolts are taking as much load as possible.

upper detail

lower detail

upper completed

lower completed

upper wireframe

lower wireframe

upper blueprint

lower blueprint

stock FXR chassis geometry

FXR chassis geometry with GSX-R forks & triple clamps

FXR chassis geometry with GSX-R forks & motolab triple clamps