Nothing is theft-proof and no locking system is perfect, but you can take steps to ensure that your bike is a less-attractive target to a thief:

• Check to see if your office has secure bicycle parking.
• Consider where and how long your bike must be parked when deciding how to secure it. If possible, keep your bike in your office or in a secured room at your workplace.
• If your bike must be parked outside, lock your frame and both wheels to an immovable object. Don t lock your bike to a sign or other object that can be easily unbolted, bent, cut or removed. Pick a well-traveled, lighted place; thieves don’t like working in exposed areas.
• Consider leaving your heavy U-lock at work, locked to the bike parking rack, and carrying a light cable lock with you for quick errands. At work, use both locks because thieves need different large, bulky tools for each type of lock. This requires more time and more risk for the thief, plus some thieves only carry tools to break one kind of lock, not both, making your bike an unlikely target.
• When not in use, cable locks can be wrapped around the seat post and U-locks can often be carried on a rear rack or bracket.
• Take all easily removed accessories with you when leaving your bike unattended.