Billed as “the world’s strongest lightest lock,” the Altor 560 uses aerospace-grade titanium that claims to be far tougher than commercial titanium, while maintaining the same light weight. At just 584g, the folding, segmented lock is indeed shockingly light—and easy enough to wedge into a pocket or messenger bag without weighing you down.
The lock also has a few structural advantages over your traditional steel U-lock. For one, it saves you a little time when locking up: It operates via a push button mechanism, which means you only need to fumble for your keys to unlock the bike but not to click it down into locked position. The 560 also gives you more length to work with than your usual mini-lock—it’s easy enough to secure a front wheel and frame to a standard bike rack with its segmented tubing shape. For those who prefer to lock up both wheels, Altor also sells a Double 560G, which is the length of two 560s linked together.
As for the lock’s purported toughness, I didn’t take an arsenal of weaponry to it, but Altor claims to have—and says the 560 can dull the blade of a hacksaw and stand up to chisels and wedges, and even bolt cutters. The patented titanium joints are as thick and impenetrable as the links, Altor says. To put numbers to it, the lock is half an inch thick and a 36 on the Rockwell hardness scale, which makes it technically less hard than steel but also less brittle, which ultimately makes it tougher.
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It comes with a bottle cage mount, called the 560Grasp, and a Velcro strap that makes it easy to holster to your hip. Of course, I carry mine stuffed into a back pocket. It doesn’t fit quite as neatly as my old mini U-lock but it also doesn’t weigh down my pants—and my bike is always still at the bike rack when I come back to it.