I have an intimate relationship with my bike lock. In fact, I dance with it. It is not, at first glance, an obvious dancing partner—a heavy chain swathed in a black nylon sleeve, but then there are many unlikely dance partners in our lives. Just as many people will do an unconscious two-step when they are opening the refrigerator, or a little foxtrot as they swivel into their car, the process of locking and unlocking my bike has, over the years, evolved into a brief little waltz that I dance to perfection. My gaze is always adoring.

I have feelings for my bike, too, but the bike, for all its elegance and functionality, lacks something my bike lock has, namely a sense of bravery, maybe even a touch of the heroic. This is because my bike lock protects my bike. It makes the bike a feasible proposition. It is what stands between me and the bicycle thieves. It keeps my bike mine. These thieves are a terrible scourge on modern life, parallel to horse thieves once upon a time. And I seem to recall, from watching old Westerns, that nothing got people so agitated as a horse thief.

I grew up in New York City, and therefore have a long history of city biking, and the corresponding history of anguish of having a bike stolen. As a kid, I had a few unfortunate experiences that I suppose you could put under the general category of “mugging.” But then what do you call it when you are eight and some bigger kid asks to ride your new blue bike in the park, and you let him, and he never comes back? The twilight of uninhibited generosity?

I was unbelievably distraught by this first theft, and a couple more like it including one, which involved curses. That may be a good dividing line: if you give your bike to someone who asks you if they can ride it while cursing you, then you have been mugged. If they don’t curse you, it’s just the capricious luck of the playground.

Then, in adolescence, I was introduced to a whole new kind of grief—the experience of locking your bike up to a pole and returning to find it had vanished. As with so much else about adolescence, I suddenly saw my childish wailing as rather privileged to this new, adult problem. At least in the old version, there was a villain, a person who had stolen it, and the actual sighting of the bike disappearing from your life. Now it just disappeared without a trace and no explanation.

These were the days of the bike lock wars. I am not talking about some competition between manufacturers, but rather the continual game of one-upmanship between the bike thieves and one intrepid company whose sole mission was to foil them: Kryptonite. They had developed something called the U-Lock, and claimed it to be unbreakable, even offering to refund the cost of your entire bike if it had been stolen because someone broke their lock. I promptly got one. For a while serenity prevailed in the bike community. And then, the thieves caught up. That episode may have been the worst- for a while there, I thought I was safe, and then one day I returned to where I had left the bike and it was gone.

This arms race of improvisation (the thieves) and evolution (Kryptonite, which kept modifying its locks to combat the thieves’ new techniques) continued until a mid-nineties innovation called, suitably, “The New York Bike Chain.”

This is my lock. This is the object with which I do my bike lock foxtrot, complete with a twirl. At first glance it seems like a rather mundane object– It’s just a big chain held together by a stout little U-lock, smaller than a fist. But, it turns out, it is the result of a long odyssey of research and experimentation on the part of Kryptonite.

People have been locking their bikes with big heavy chains for years, explained Neil McDaid, Kryptonite’s director of New Product Development. “But big heavy chains are not as indestructible as they look.”

McDaid is an industrial designer and is therefore a specialist in things that are not as indestructible as they look. His task is trying to make things look indestructible. Nothing is going to actually BE indestructible. Every lock is eventually breakable, so the issue with McDaid and his Kryptonite team is, like in Olympic high diving, the degree of difficulty in breaking it. Kryptonite says that my chain “resists attacks from bolt cutters, saws, chisels, files and hammers.” But if someone is prepared to pull up to the lamppost in front of my house with some very heavy machinery, the lock can be cut. And then there is always dynamite.

McDaid speaks as though he were a detective specializing in some esoteric criminal species, art thieves, for example, or jewelry thieves. In his case it is bicycle thieves. He once spent forty-eight hours in a van parked on Avenue A, monitoring the attempts of various thieves to break a New York Lock. The bike came under all kinds of attack, but the lock, and the bike, survived. He speaks with an Irish brogue, and a specialist’s passion for his faceless nemesis.

He explains that no matter how fat a chain-link may be, it is sold off a “coil.” You can go to the hardware store and buy it by the foot. “But if you can cut it with a bolt cutter in a hardware store, a thief can cut it with a bolt butter on the street,” says McDaid.

Kryptonite was responding to a desire for a more flexible lock, something you could use with lamp posts, trees, whatever was available. They produced a cable lock, but, alas, there is such a thing as a “cable cutter.” “We looked and looked at chains. We talked to all the biggest ‘chain and hoist’ manufacturers and they snubbed their nose at us,” he says. “They were like, ‘A bike lock-chain? That will never sell.’ They thought we were crazy. “We finally found an Italian manufacturer who made chains for those huge logging machines that go through forestry and cut down trees. They had a chain than had to go through rocks, up these rough terrains.”

Kryptonite made a deal. The manufacturer was skeptical that there would be a market for this heat-hardened, square linked heavy chain. I can imagine what these men in Italy must have been thinking, that it was too unwieldy, that it was the sort of object whose heft would make casual use seem impractical. But they wouldn’t know about the fierce protective urge of New York City bikers, who want to have their bike and park it, too. They wouldn’t have imagined my own little dance with my lock. My faith is such I leave my bike locked up to a lamppost on the street every night. And every morning, it is there to greet me. I do my lock dance before my first cup of coffee.