I have a Kryptonite ML18 (a long-shackle variant of a Faghedaboudit), about 5.6 pounds, and a Kryptonite Series 2 budget model, probably about 3 pounds. Recently I picked up an Evolution Series 4 for a pretty secure lock that's not much heavier than the Series 2, at 3.3 pounds. I usually leash the front wheel with a medium cable when parking short-term.