Unless you keep your bike with you in your office or classroom a lock is a must. There are two main types of locks cable locks and U-Locks. A cable lock is just like it sounds-- a peice of cable attached to some type of locking device. They tend to be less secure and easier to defeat than a U-Lock. Click on the locks below to read more about different types of Locks and hints on how to lock a bike most securely.
Three graphics, cable locks and U-Lock and How-To lock