Hey guys.
So I'm planning a wider single sided swingarm in my shaft drive KZ750. It's about 45mm wider than the stock swingarm. Removing that much material from the frame will leave it extremely weak.
It's shaft driven so I can't narrow the swingarm as you'd have to take all the material off one side only (the other side locates the driveshaft to the motor) which will offcourse leave the rear wheel 45mm to the one side.
I can't find any examples on the net of how people have done this on an 80's tubular frame. The singarm pivot is right where 3 tubes come together.
My one idea is to do the following:
-Machine down the outside of the frame so it's flat at the pivot point exposing the 3 connecting frame tubes. (It will still be held together by the inside "flange")
-Weld on a new (say 12mm) steel plates of the appropriate shape to the outside of the frame "overlayed" onto the 3 tube joint giving it some more width and reinforcing.
-Machine a new pivot hole into the plates, about 25-30mm larger in diameter than the original swingarm pivot holes.
-Now, with the material added to the outside, go ahead and machine the inside of the frame to gain the 45mm extra width required. Weld up the inner sides of the 3 frame tubes for strength.
-Machine some new metal round tube bushings with say 10mm wall thickness and weld them into the holes mentioned above. Both inside and outside.
-Finally thread these bushings to accept the swingarm pivot bolts.
-Weld in some additional bracing and gussets to the frame as required.
This picture illustrates the setup I'm working with.
http://www.partzilla.com/parts/search/Kawasaki/Motorcycle/1983/KZ750-N2+Spectre/FRAME/parts.html
Let me know if you think my approach is workable and safe or if there is a better way?
So I'm planning a wider single sided swingarm in my shaft drive KZ750. It's about 45mm wider than the stock swingarm. Removing that much material from the frame will leave it extremely weak.
It's shaft driven so I can't narrow the swingarm as you'd have to take all the material off one side only (the other side locates the driveshaft to the motor) which will offcourse leave the rear wheel 45mm to the one side.
I can't find any examples on the net of how people have done this on an 80's tubular frame. The singarm pivot is right where 3 tubes come together.
My one idea is to do the following:
-Machine down the outside of the frame so it's flat at the pivot point exposing the 3 connecting frame tubes. (It will still be held together by the inside "flange")
-Weld on a new (say 12mm) steel plates of the appropriate shape to the outside of the frame "overlayed" onto the 3 tube joint giving it some more width and reinforcing.
-Machine a new pivot hole into the plates, about 25-30mm larger in diameter than the original swingarm pivot holes.
-Now, with the material added to the outside, go ahead and machine the inside of the frame to gain the 45mm extra width required. Weld up the inner sides of the 3 frame tubes for strength.
-Machine some new metal round tube bushings with say 10mm wall thickness and weld them into the holes mentioned above. Both inside and outside.
-Finally thread these bushings to accept the swingarm pivot bolts.
-Weld in some additional bracing and gussets to the frame as required.
This picture illustrates the setup I'm working with.
http://www.partzilla.com/parts/search/Kawasaki/Motorcycle/1983/KZ750-N2+Spectre/FRAME/parts.html
Let me know if you think my approach is workable and safe or if there is a better way?