Replacing worn or frayed inner cables is pretty cheap, and you may have to do one or two. When they are new I cut to length and put a drop of super glue on the end. Then I put a 1/2 inch piece of heat shrink tubing on an shrink it. Later, if I need to remove the cable, I can remove the heat shrink, and the glue will keep the cable from fraying.
Try it. bk