Found this photo on craigslist. It is an epic failure of securing your bike. All a would-be thief needs to do is remove the front wheel and lift the fork out of the U-Lock. Done. All you need is a wrench, and about sixty seconds.
When securing your bike, please make sure your lock runs through the wheel and around the frame of the bicycle, and lock it to a bike rack or something else with a "top," which means make sure that nobody can just, say, life the bike, lock and all, up and over the top of a post.
Some not-so-obvious things I have locked my bike to:
- A handrail. The last time I went to the barber shop, there was absolutely nothing to which I could lock my bike. Except for a handrail attached to the brick building, alongside a short flight of steps. I hooked my handlebars over the handrails, and locked the wheel and frame to the bar.
- A chain-link fence. I stopped at a convenience station to buy some doughnuts and a newspaper to take to work, and could not find anything suitable to lock my bike to, except for a chain-link fence behind the store. I again hooked the handlebars through the chain so the bike was suspended in mid-air, and then looped my chain through the front wheel and around the frame, and latched the whole thing to the fence.
All I use to lock my bike is a bike chain that I found lying on the ground in a parking lot in San Diego, and the padlock I bought to secure the U-Haul that moved us to Denver. It's a simple set-up.
Most, though, suggest using a combination of locks. A chain and a U-Lock, for example. Use your own judgement.