Let me tell you folks some bad news. I am a tool freak and I have several tols in my shop that could enable me to get your bike faster than you could with your key.

The huge u-bolt style locks are the toughest I have seen but I even have a cutter that can snap those in one squeeeze of the handles. One of my old jobs required that I be able to cut padlocks off and I collected the tools to do so. I have not met a hardened shaft samller than 1/2 inch I could not snap in a few seconds.

If you lock it in a public area in plain view it is much safer. But under no circumstances leave it locked outside after dark. If some one wants that bike and they have the relatively cheap tools to get it it will be gone.

You also have to consider what you are locking it too. Would it be easy to break or cut the anchor you used? Locking your bike to a tree with a chain? A good axe with that tree as a backing plate will chop a chain of sizes smaller than 5/16th and most bike chains I see are much thinner than that.

Locks are to keep honest people honest. A skilled and well equipped theif will steal whatever he wants.