Leave a bicycle locked up on the street, and a pro with the right tool can spring it faster than you can buy a Slurpee. We're not bike thieves—not even close—and we were able to slice through cheap locks with $20 bolt cutters and a hacksaw, on our first try.

So we wanted to see how much a quality U-lock increases the odds that your ride will still be there when you get back. We put four popular brands of locks against those hand tools, and the bike thieves' weapon of choice—a cordless angle grinder. In the end, we found some locks that can buy you a few extra seconds of security. But the results conclusively proved one thing: Your bike is never really safe outside.

Testing Methodology

These four mid-range locks (~$50 street price) are large enough to fit around a bicycle frame, a wheel and a parking meter. All of these manufacturers make locks that are more expensive and heavier, but we chose these for their affordability, convenience, and for the fact that these are the locks we see people using all over NYC. They're made of hardened steel and outfitted with complex locking mechanisms. Beyond the security of the locks, we looked at cost, weight, and how well the locks mount to your bike.

The hand tools in our test included the $20 bolt cutters and the hacksaw mentioned above, the latter of which had a fresh, tense blade ready for each new lock. We went to work with each of those for five minutes and measured the results. (We tried out a Sawzall, which did the same level of damage as the hacksaw, just more quickly.)

For our primary power tool, we used a the cheapest angle grinder we could find—a Ryobi 18-volt lithium-ion tool—which cost $40 for the tool, and totaled just under $100 with a battery. We fitted it with new Bosch-branded 4 1/2-inch-diameter, 7/8-inch thick cutoff wheels. With a little practice, let's just say, we didn't need the full five minutes to measure the damage.

And remember, we're inept. For a pro, a bike locked up on the street must look like free money. Lay out $100 for a power tool, and you could just go get a new bike. Any bike you want. Again and again. And these four locks are usually all that's there to stop you.

The Best Bike Lock

The Best Bike Lock

Fourth Place: Blackburn Leavenworth

This Blackburn Leavenworth's unusual hexagonal design is coated in thick rubber, which protects your bike, but that's where this lock's advantages disappear. It's heavy, considering it's the smallest lock we tested, and the shackle's angles make it trickier to squeeze onto a tight post. Furthermore, the keyhole is finicky and often requires some shaking and banging for the key to turn. The mounting bracket attaches easily to your bike with a hex key, but the lock rattles a lot while you're on the road, and it slides around on your bike's frame.

Oh, and it's hardly better than the cheap off-brand locks we cut—despite being the thickest of the bunch. The bolt cutters only made some dents, but we were able to cut nearly all the way through the lock with the hacksaw in just five minutes. It didn't even last a minute against the angle grinder.


Blackburn Leavenworth Specs
• Weight: 44 ounces
• Thickness: 16mm
• Price: $43 (Amazon)
Gizrank: 2


The Best Bike Lock

Third Place: Abus Sinero 43

Abus makes some of the most intense—and expensive—locks on the market. Sinero is one of its more modest products, and it was the slimmest and lightest we tested.

The Sinero's mounting bracket is a pain—it's trickier than most to attach to your bike, and you've got to actually lock in to the mount, which is awkward and time-consuming. Despite being just 12mm thick, it's tough. Hand tools did nothing but slice the soft protective coating, not even making a mark on the steel. But against the angle grinder, the Sinero held up for a minute and a half. After the lock was cut, it lost the integrity of its shape, and we were able to easily pull it free from the bars it was locked to.


Abus Sinero 43 Specs
• Weight: 38 ounces
• Thickness: 12mm
• Price: $50 (Amazon)
Gizrank: 3


The Best Bike Lock

Second Place: Kryptonite Evolution Series 4 Standard

Kryptonite locks are very popular, and they have a reputation for security. We just wish the company's mounting bracket was better—it's tricky to install and use without ever being secure against the bike's frame. It attaches to your bike with a one-way sliding tab, which clicks tight, and then you clamp it down with an included hex key. Still, the lock wavers left and right while you ride. We ended up abandoning the bracket altogether. But at least the lock's finish doesn't scratch your bike when it's threaded under the brake cables. And, when opening and closing it, the key turns smoothly in its hole.

Bolt cutters did no damage to the Evolution, and the hacksaw just skated harmlessly along the surface of the steel. The angle grinder, on the other hand, sliced through it in two minutes. Still, we had it locked up tightly, and even after the lock had been cut, it required some effort to spring the bike free.


Kryptonite Evolution Series 4 Standard Specs
• Weight: 60 ounces
• Thickness: 14mm
• Price: $53 (Amazon)
Gizrank: 3.5


The Best Bike Lock

Bestmodo: OnGuard Pitbull STD

Despite its fat locking mechanism, the OnGuard Pitbull STD is a breeze to use. The lock clicks into a sturdy, secure mounting bracket that doesn't bounce around while you're riding. Added bonus: you can change the direction of the mount with a screw driver, so you can attach the lock to your bike in whatever way is comfortable ways. The key slides in smoothly without any jerking around.

Security-wise, this lock is basically identical to the Kryptonite. It's invincible against hand tools. But it didn't last two minutes against the angle grinder. Look, nothing stood up against the angle grinder. And we're not talking about a 2100-watt Milwaukee metal shop tool—we used the cheapest damn angle grinder we could find.

This lock, like the Kryptonite, was also tough to spring free once it had been cut. But a little wrestling got it off, and, presumably, your bike would've ridden off with it. And this was the best of the bunch!


OnGuard Specs
• Weight: 48 ounces
• Thickness: 14mm
• Price: $55 (MSRP)
Gizrank: 4


Coming soon: We discuss the results of our test with an anonymous NYC bike thief.

Video by Michael Hession