U-locks are without a doubt one of the most convenient and secure ways to lock your bicycle. Relatively small and compact, U-locks are very strong and have a high theft-resistance. We keep Kryptonite U-locks on hand in a couple of different sizes and quality levels and are happy to explain the difference between them. Cable locks are also available, but we consider them to be less secure and should be primarily used to protect things like wheels. Used in conjunction with a U-lock, cable locks are a perfectly acceptable way to keep someone from waltzing off with your front wheel or seatpost.The Kryptonite Series2 Mini U-lock is an affordable option with a lot of security. They feature a disc style key which is nearly impossible to pick open, a tough steel shackle and crossbar, and come with a frame-mounted bracket for storage. The smaller size prevents insertion of a car jack or pry-bar to bust the lock open and makes it lighter and more convenient to carry. We sell the Series2 Mini for $39, and are happy to install the bracket on your bike and show you how to use the lock in the most efficient way possible. It comes with registration paperwork to send in to Kryptonite in case you lose your keys. Kryptonite also offers an anti-theft lock guarantee if you can provide the broken pieces of your lock. We also have the standard size Series2 lock for $40, and the wide ATB size for $42. We also have Kryptonite 4-digit combination locks so you never have to worry about keys (either finding them or breaking them). The step above the Series2 is the orange-shackle EVO U-lock from Kryptonite. Made from an air-hardened steel, the lock itself weighs the same but is many times more resistant to being cut with any kind of toothed blade. But back to the locks: we have them in several sizes including the Mini (image right), the Standard, the Mini Long-Shackle (same width, longer u-bracket for improved lock option choices), and the wide ATB. They all have the disc style key, an included mounting bracket, and registration paperwork. One of the included keys has a small LED light for night-time lock and unlocking. They retail for $68 in all sizes.