Originally Posted by
reshp1
The cable housing needs to begin and end with a cap (called a ferrule). Otherwise the soft cable housing will squeeze through the cable stops on your frame and components and cause major issues. Ferrules are the ones that slip snugly over the cable housing end.
You should probably read this, twice:
Sheldon Brown - Cables
Cabling is one of the most overlooked aspect of bike building, and one of the most common causes of issues.
All great advice. Pay special attention to the preparation of the housing ends, per the Sheldon Brown article. Use only metal ferrules for brake housings; shift housings can use plastic but I prefer metal for both; the housing has been known to work its way through plastic ones. I also use his advice to bend compressionless shift housing to its approximate shape before cutting, especially the lower loop going into the rear derailleur, due to its sharp 180 degree bend. Keep an eye on this run of housing, it tends to collect water and road crud.