I use a small cable lock all of the time when my bike is close at hand and I'm making quick stops. I've used this lock for probably 15 years with no problems. Can't recall the brand but it's probably Kryptonite. If I'm leaving my bike unattended or in a high-risk area, such as outside my office during work, I use a Kryptonite New York u-lock with a 4-foot cable connecting to the front wheel.