Many bicycle U-locks that come with a round cylinder type key can easily be unlocked with a common pen. UPDATE NOTE: After posting this video, Masterlock contacted me and replaced my lock for free. They said the two customer service reps I spoke to should have replaced my lock and they apologized.... A bike lock is an important security apparatus that allows you to lock your bike when you are not with it A bike lock is attached around the frame of your bike and Master Lock Tough Under Fire Master Lock Bike offers street smart security with Best Bike Lock HQ provides info on the best bicycle locks including chain locks cable locks u-locks and padlocks to protect against bike theft We are specilized in manufacturing bicycle lock and cable lockWe mainly offer a variety of bicycle lock and cable lockand types of For bike