My rear cable housing got torn apart while I was tunning gears as you can see in the picture. I'm quite new to cycling so i'm not sure if i should replace the whole cable or just the part of the housing which got damaged?
Also if I'm just replacing the cable housing, do i have to cut the cable as there is a nut at the end of the cable which stops me sliding the housing out of the cable?
(just for your information i have shifting issues in the rear derailer as well: i.e., for certain gear combinations it sometimes overdo the gears when upshifting and downshifting. Maybe be this is related to a bad cable as well)