Locks, lock mechanisms, lock assemblies, retro fit kits, and methods of using locks with cables and chains inside of strengthened flexible sleeves can conform to shape surfaces to which they are mounted, for preventing thefts of bicycles, motorcycles and other applications, such as but not limited to securing gates and doors, and other objects together. The flexible sleeve can include a series of ball and socket segments arranged next to one another, having a hollow conduit through which the cable or chain can pass through.