Bicycle lock

Type of lock used to secure bikes Frame and front wheel secured A bicycle lock is a security device used to deter bicycle theft, either by simply locking one of the wheels or by fastening the bicycle to a fixed object, e.g., a bike rack. Locking devices vary in size and security, the most secure tending to be the largest, heaviest and least portable. Thus, like other security equipment, bicycle locks must balance the competing interests of security, portability, and cost. Some are made of particularly expensive materials chosen for their acceptable strength and low density. Types U-locks and D-locks U-lock A U-lock is a rigid metal ring in the shape of the letter U. The U part of the lock attaches to a crossbar section, and for this reason they are also called D-locks. To lock the bicycle, one locks it physically to some other object, such as a bike rack, parking meter or other pole installed securely in the solid ground. Merely locking the bike frame to the wheel is not recommended because, although it cannot be rolled away, the entire bicycle can still be lifted and carried away or deposited into a vehicle. U-locks are more secure than most other kinds of locking mechanism becaus