When purchasing a cable it is important to lubricate the cable before installation. Most modern cables come with a nylon sleeve inside the housing, insulating the cable itself from the housing. However, moisture can still get inside the housing and over time, the cable can wear through the protective nylon layer. To get the most out of your cables, I recommend lubing them several times a year depending upon riding conditions, this will prolong the life of your cables and prevent premature wear and stretching. Also available is the Motion Pro Cable Lube!