[jbranson]

If SA length is the issue (and almost all the CB's handle a bit better with a longer swingarm) then just cut it and add a couple of inches.
JohnnyB

 

[jbranson]

Yeah it would be effective....might not save much weight really...but would probably be much stiffer for about the same weight.

Might be some work to adapt a modernish Aluminum swingarm to an older bike though. Would look very trick. Probably worth a shot trying to find something close. Only problem with aluminum would be any modifications needed (welding) might be a bit trickier.

JohnnyB