Recabling my bike today. Everything seems pretty straightforward except one thing.
The small piece of cable housing that goes into the shifter itself -- is there any kind of cable end/cap in there that needs to be replaced, or do I just slide the new outer into place and it seats in some integral spot inside the shifter?
too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
It's almost always preferable to use a ferrule. If for no other reason than confining erosion damage caused by the sharp end-on wires to a replaceable part. However some levers don't have the room for a ferrule in the fittings. It's an easy decision to make. If there's enough room - the fitting has a bigger ID than the housing OD - use a ferrule. If the housing is a slip fit to the fitting than don't (because you can't anyway).
Whether or not a ferrule is required at the lever end, be certain to prepare all of the cable ends correctly; cut them straight across, grind or file them flat and use an awl or similar to ream open the inside opening. Use metal ferrules, I have seen plastic ones crack and split due to braking stresses. Use brake cable ONLY, never use compressionless shift cables for brakes, it can fail without warning. Poor preparation wil result in spongy braking feel.