Bicycles are thief magnets. They’re a low-hanging fruit, after all, being parked in public places, with nothing but a lock or two holding them down in their place. That’s why, if you’re getting around by bike, you need a proper bike lock or two (or even three) to secure it.
How secure is a bike lock? Truth be told, not that much. A brazen thief unafraid to use a power tool like an angle grinder, for instance, can cut through any kind of lock in literal seconds. Of course, an angle grinder makes loud power tool noises that can attract a lot of attention, which is why most thieves will work with lock picks, hacksaws, and bolt cutters, instead.
When judging a bike lock’s effectiveness, we generally use those three hand tools as the metric. As in, how well does it stand up to thieves picking the lock, sawing through the shackle, or cutting through it with a bolt cutter? All the bike locks included in this list should hold their own against any of those actions, which leaves you having to decide which one to get based on other factors, like weight, size, and overall aesthetics.
Kryptonite New York Fahgettaboudit Mini
This U-lock may be small in size, but it is easily one of the heaviest bike locks we’ve handled at 4.55 pounds. That’s quite a testament to its solid build, which includes an 18mm shackle, a through-hardened dual-deadbolt system, and an extra metal crossbar to keep the shackle from rotating when it’s cut in one place. It uses a disc-detainer locking mechanism, by the way, which any lock-picker will tell you is one of the toughest to either pick or drill through, while the hardened max-performance steel construction should resist most everything but the nastiest attacks. Think you can freeze the hardened steel shackle and smash it with a hammer? Good luck with that, especially with this thing’s 18mm thickness.
The downside? The weight is pretty ridiculous for a bike lock. Carry two of these and that’s over nine pounds of heft immediately added to your bicycle. And yes, no mounts are included, so you’ll have to buy them separately if you want to keep them from moving around on the frame.
Alternative: If you want something lighter, check out the Kryptonite New-U Evolution Mini-7, which uses the same build and locks, albeit with a slimmer 13mm shackle.
Knog Strongman
No, it doesn’t have a plastic shackle. Instead, it uses 13mm hardened steel for the shackle, which is then overmolded with UV-resistant silicone, so the shackle can brush up against your bike frame a hundred times without leaving any marks or scratches (not to mention, it adds an extra layer against the freeze-and-hammer breach that some thieves prefer). It uses a disc-detainer mechanism inside the lock body, so it offers a serious challenge to picking and drilling, although the body is only made from cast steel, making it a potential point for breaching. Each unit of this U-lock includes a frame mount, so you don’t have to struggle finding a way to hang it on your frame in a flush manner (so it doesn’t swing around) – just install the mount and secure the lock there every time it’s not in use.
ABUS Granit X-Plus 540
With a 13mm shackle made from hardened steel and a pre-stressed shape that can resist pulling forces, this U-lock’s shackle will resist most any attack that does not involve power tools. The lock body is also made from the same tempered and hardened steel, so it will hold up just as hard as the shackle does to cutting attempts, while the dual-bolting disc cylinder mechanism it houses should deter everything but the most sophisticated attempts at picking and drilling. If you ride an e-bike, it can also be rekeyed to use the same one as a locking Bosch battery, so you can carry one less key in your everyday commute.
Kryptonite New York Legend
A chain lock, it uses massive 15mm round links made from 3T hardened steel that are going to be downright hellish to cut through using any manual tool, with the three-foot chain allowing it to wrap around most sections of the bicycle. It comes with a shackled padlock that’s completely covered in a reinforced shell, all while using the same double-deadbolt, disc-detainer locking mechanism that makes the outfit’s U-locks require seriously sophisticated picking methods to disengage. At 9.5 pounds, though, it’s even heavier than the New York Fahgettaboudit Mini U-lock, making it quite the hefty gear to lug around.