With an 18 mm dual-locking hardened shackle, the Kryptonite New-U New York Fahgettaboudit Mini held up better than any other lock-except one-against cutting attacks. (The company’s New York lock series-including our upgrade pick and the chain pick below-is covered even in Manhattan.) Two caveats on the latter: You must register your lock within 30 days of buying it, and the anti-theft protection on this lock does not apply to residents of Manhattan, where theft is very high. It also comes with a 4-foot cable to secure the front wheel, plus a free year of Kryptonite’s anti-theft protection. The New-U Evolution Mini-7 uses a disc-detainer locking mechanism, which is much harder to pick than a typical wafer lock and should foil all but the most savvy criminal using specialty tools. On top of that, the shackle in this design has an additional cutout at the end, which makes rotating (and therefore removing) it after cutting it even more difficult. Measuring 7 inches long and weighing a little under 3 pounds, it’s the perfect size for most people-long enough to lock the wheel and frame of most bicycles to a rack while leaving almost no room for someone to wedge a pry bar or a car jack inside it.

Once our testing began, we immediately saw the huge advantage this lock had over the competition: Its 13-millimeter hardened shackle (the big U-shaped loop that gives U-locks their name) can withstand bolt cutters, eliminating a large percentage of potential thieves. The Kryptonite New-U Evolution Mini-7 should withstand attacks from everything but power tools under most circumstances.

Anti theft locks laptop