Stolen Bicycles

All of a sudden, we are having bicycles stolen from racks(bicycle) outside of the respective
condo units....... One 3 months ago and two a week ago.I believe (though not sure) that individuals
are using those bicycle locks that they buy at the bicycle shop and appear to be easily cut.

Has anyone had such experience? Is the answer to suggest to the people that they buy actual
chains from Lowe's or Home Depot and a master padlock rather than relying on those so-called bicycle
locks?

Alex,

I play around with locks and lockpicking. I also used to cut locks when I managed self-storage facilities.

The shackle on a padlock is its weakest point. The smaller the diameter the easier it is to cut. The more shackle exposed, as on a bicycle lock, the easier it is to cut. I would recommend a shackle diameter of no less than 3/8" of an inch and each increment over that is even better. My first recommendation is an American Lock Company model A700. This lock features a 7/16" diamter shackle. You can usually find these at hardware stores for around $35. The model AH10 is a good alternative as it is pretty much the same lock with a different kind of tumbler.

Same goes for chain. Get a length of the heaviest chain that you can get on the lock and use no more chain than needed. Excess chain is like excess shackle: an easy place to cut.

There is no such thing as a lock that cannot be bypassed. Bolt cutters are the favorite tool of bike thieves and large-diameter shackles and chains require larger bolt cutters. Your best defense is to make the thief use such a large bolt cutter that it cannot be easily concealed. Battery powered cutting wheels can defeat just about any lock, but they make noise and create a shower of sparks that calls attention to the user.

The last thing you ever want to use to secure anything is a laminated Master padlock. Aside from the fact that at least a million other people will have the same key you do, Master locks are just about the easiest lock to pick. I have a number of them that I acquired over the years for which I have no keys. My average time to pick them open is about 30 seconds.