Angle grinder bike. The testing methods

Most Secure Bike Lock in 2023: Top 5 Thief Heart-Breakers

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Bike theft is a big problem. In 2021 alone, 1100 bikes were stolen every day in the UK: that equates to 45 per hour. In the United States, 190,000 thefts are reported each year, so it’s hardly surprising that cyclists feel inclined to invest in high quality, high security locks.

Finding a good lock is easier said than done, though. There are tens of thousands on the market ranging from cheap and basic locks to super high tech and even Smart locks, so it can be exceptionally difficult to know where to start. Some bike locks are designed to work with bike covers, others to operate in isolation.

Bicycle thieves are a resourceful bunch and it sometimes seems that the more advanced locks get, the more ingenious ways thieves find to break through them. Research is essential, especially if you own a higher end bicycle that’s more vulnerable to theft. Commuters are at extra risk as they often leave their bikes unattended all day, making them easy targets for thieves.

Losing your bike to theft is more than demoralising. It deprives you of your way of getting around and just makes life more difficult. Fortunately, we’ve done the research for you and collected the best, most secure bicycle locks currently available.

What to Look for in a Bike Lock

Long gone are the days when locks consisted of simple chains. Think carefully about the level of security you want, the kind of lock and the features it offers. Consider where you usually park your bike: crowded streets are safer and theft is more likely in lonely, isolated spaces.

Smart locks are nowadays all the rage. These allow you to unlock your bike via a smartphone app or even a fingerprint, and they offer peace of mind because you’ll always know that the bike is locked. traditional locks are still favoured by many, though, as they’re cheaper and less complicated.

Locks come with a range of features that are largely determined by their price tags. For example, anti-angle grinder locks are expensive but offer extreme protection and mean that thieves will never be able to cut their way to your bike. These are an excellent choice if you own an expensive, high end bike, which is more of a target. Other locks come with anti-tamper alarms, which means that they’ll sound a loud siren if someone tries to interfere with your bike.

Think about how you want to use the lock, too. Simpler designs are made to be weaved through the wheels, others are designed to fit a U-lock through a pole. Thickness is also important. A thin, cord lock won’t withstand bolt cutters, for example.

Padlocks are more secure and U-locks are generally considered the best, but it depends on the material. Steel alloys are the most resistant and make it extremely difficult for thieves to cut through to your bike.

Is There an Unbreakable Bike Lock?

No bike lock is or ever will be 100% unbreakable. As technology advances, so too do the thieves, constantly inventing new ways to circumvent security. Nearly every bike lock can be broken with specific tools and enough time, but that doesn’t mean that some aren’t very, very secure.

Bicycle thieves employ everything from simple bolt cutters to angle grinders to get through locks, and given enough time they can crack even the most expensive kit. Of course, the stronger the lock, the more time it takes to crack. A bicycle thief is unlikely to spend hours working on a lock and most are opportunistic, so a robust lock acts as a strong deterrent.

over, while there’s no such thing as an “unbreakable” lock, there are plenty that come close. Steel alloy U-locks with anti-angle grinder features are nearly impossible to break, especially in the short time that a bike thief is likely to spend trying. Alarms are also a strong deterrent: interlopers will almost certainly flee rather than hang around when one goes off.

In short, thick locks made from high grade metals will keep your bike extremely safe. You might not be able to find a truly unbreakable lock, but you can certainly get locks that offer unparalleled security and make thieves’ lives incredibly difficult, especially when combined with other precautions.

Most Secure Bike Locks [Top 5]

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To find out, MCN headed to Image4 Security in the West Midlands – the people who design and build products including the Guardsman garage door defender and the Apex ground anchor. I explained that I’d got no experience using an angle grinder, which I expected to be good news for them as I was about to set about cutting up their products.

But actually, what followed was a crash course in metal cutting and a few practice cuts on some scrap they had lying around. With my Scouts badge in metal destruction attained, I set about doing my worst to Image4’s Apex Pro ground anchor, which is rated Motorcycle Diamond in Sold Secure testing.

Frustrated by design

Within around five minutes I’d made a pretty decent cut the length of the anchor’s tunnel which seemed like the most logical place to start. I was pretty pleased with my efforts but dismayed to find that the Apex was standing its ground. I didn’t expect this single cut to defeat the device but I’d failed to create even a modicum of give or flex so our bike was safe for now.

The next most sensible cut seemed to me to be one parallel to the first. This took another five minutes and brought about the end of the first cutting disc – but had no effect whatsoever on the integrity of the ground anchor. At this point, I struggled to imagine a thief fitting a fresh disc after 10 minutes of making a racket in a stranger’s garage, but in the interest of science I persevered.

A third cut perpendicular to the first two still did nothing to the Apex’s structure and although a few hammer blows did now deform it, it would still be holding onto its prized motorcycle in a garage or lock-up.

So, I think it’s safe to say that the Apex Pro is impervious to attack in a real-world setting with sparks flying and a screaming angle grinder in your hand in someone else’s garage. The next logical place a thief would try to cut is the chain.

Image4 don’t manufacture chains but they conducted extensive tests on chain products from various markets – as their so-called ‘chain graveyard’ attests – in order to choose the ones they supply. They eventually settled on a fairly high carbon steel construction in various sizes.

With my angle grinder technique improving, I set about a fairly portable 13mm chain and a chunkier 20mm version. Terrifyingly, I was through the smaller chain in around 30 seconds and the bigger in 1m 30s – albeit with the chain secured in a vice, which wouldn’t be the case for a thief and it would be harder with the chain looped around the bike and anchor with no slack left exposed to attack.

Security takes work

Chains can be defeated by angle grinders. Naturally, I knew this before – I’ve seen enough videos of bikes being taken to have made this discovery. But far from this giving me a feeling of helplessness or wondering ‘what’s the point?’ if they’re going to get it anyway I feel a renewed sense of determination.

I want to make the task of stealing my motorbike as difficult as humanly possible, why give the criminals an easy ride? Force them to use a noisy angle grinder rather than being able to lift or wheel it away.

Use layers of security so more than one tool is required. Get an alarmed disc lock to accompany the sound of the cutting disc. If we give up just because angle grinders exist, we may as well just start leaving the keys in the ignition.

The best bike lock

With a dual-locking hardened 13 mm shackle, an included cable, and a free year of anti-theft protection, the Kryptonite New-U Evolution Mini-7 is a good deterrent at a reasonable price.

Buying Options

At the time of publishing, the price was 91.

The Kryptonite New-U Evolution Mini-7 should withstand attacks from everything but power tools under most circumstances.

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.

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.

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.

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.

It also comes with a 4-foot cable to secure the front wheel, plus a free year of Kryptonite’s anti-theft protection. 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. (The company’s New York lock series—including our upgrade pick and the chain pick below—is covered even in Manhattan.)

An even stronger lock

This lock is more secure than our top pick, but it also weighs a lot more.

Buying Options

At the time of publishing, the price was 159.

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. (That exception is the Hiplok D1000, which costs 300; see “What about the Hiplok D1000?” for more about it.) Even with a powered cut-off wheel, our testers took over a minute to make the two cuts necessary to remove it—four times longer to grind through than with the New-U Evolution Mini-7. However, this lock doesn’t come with a cable, and it weighs almost 4.5 pounds, a full pound and a half more than the Mini-7. But if you’re in a high-risk area, and can’t spend 300, this lock is the one to buy. Like our top pick, it uses a very secure disc-detainer mechanism, and it’s long enough to fit around your bike’s frame and your wheel without becoming too cumbersome. For extra peace of mind, it also comes with a free year of the highest level (5,000) of anti-theft coverage from Kryptonite. (Again, you have to register your lock within 30 days of purchase for the coverage to take effect.)

Best chain for the money

If you need more length in your lock and weight is of little concern, the 10-pound Fahgettaboudit Chain is really tough.

Buying Options

At the time of publishing, the price was 116.

If you want to secure more than just your bike frame and wheel, if you have a cargo or electric bike that needs a longer lock, or if your favorite spot to lock up is around a street post, go with the Kryptonite New York Fahgettaboudit Chain, which is one of the toughest chain locks we tested. We encountered other chain locks that were harder to cut through, but they either cost more or weighed more. It has 3 feet of 14 mm hardened links held together by a 15 mm Kryptonite New York Disc Lock, and it should keep all but the most determined thieves at bay.

A medium-security folding lock

This relatively lightweight folding lock can wrap around odd angles more easily than a U-lock and is more secure than a cable lock—but it’s not nearly as strong as a chain, and it’s pricey, too.

Buying Options

At the time of publishing, the price was 76.

If security is your only concern, we recommend skipping a folding lock altogether because the rivets are easy to break. But there are a few special requirements that folding locks can accommodate that other options can’t: You can lock them around large or strange shapes like handrails or lamp posts, they’re much sturdier than cables, and they’re a lot lighter than chains (and a pound lighter than our top U-lock pick, even minus its cable). We believe the Kryptonite Keeper 585 offers the best combination of security, weight, and price among folding locks. It also comes in a longer, 100 cm (39-inch) version, the Keeper 510.

The Keeper 585 measures 85 cm (32 inches) long, weighs 1.7 pounds, has 3 mm hardened steel rivets, and comes with 500 of anti-theft protection from Kryptonite. Is your bike worth thousands more than 500? That should tell you everything you need to know—get a stronger lock.

Watch Us Cut This “Angle Grinder-Proof” Bike Lock

The Altor SAF Lock eventually succumbed to the grinder, but it took more than hour of cutting.

By Dan Roe Published: Aug 30, 2019

No bike lock is immortal. Well-tooled thieves can dissect, dismantle, cut, or bludgeon most locks into submission with a variety of hand tools.

But one of the most effective assets for anyone looking to steal your wheels costs 100 at Home Depot: The cordless angle grinder. Thanks to the latest lithium-ion battery technology, these portable power tools fit in a backpack and cut through any hardened steel shackle or chain link in under a minute—we’ve tried it ourselves, and so have the City of London Police. That’s what makes the marketing claim behind the pre-release Altor SAF Lock so compelling: It’s the world’s first angle grinder-proof bike lock.

So when Altor asked if we’d like to attempt to cut the mighty SAF Lock ourselves, we took the company up on the challenge.

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At 13.7 pounds, it’s twice the weight of a Kryptonite New York Fahgettaboudit Mini U-Lock and about as heavy as a 5-foot Kryptonite New York chain lock, so don’t think of the SAF Lock as a regular bike lock. It’s designed to be stationary. “It’s really just for having outside your home or place of work, the way chain locks are now,” says Jon Akers, Altor’s head of marketing and sales.

Its 75mm shackle includes two forms of defense. Inside, there’s a 14mm hardened steel shackle, the type you’ll find on portable U-locks, but it’s surrounded by an aluminum shell. A softer metal, the aluminum is used to wear down the grinder’s disc and battery by virtue of its thickness. The shell also includes a series of internal notches that chip and degrade the grinder disc as you cut.

The SAF Lock’s hardened steel shackle is similar to other U-locks, but the aluminum shell is what protects it from a 4.5-inch angle grinder disc. Those notches are there to beat up a grinder disc.

The shackle’s inner diameter is narrow enough to prevent a clean 360-degree cut through the lock, meaning you’ve got to go straight through the shackle to make a full cut. Both sides of the shackle lock into the cross bar, so two cuts are necessary to defeat the lock, and the cross bar uses a disc detainer mechanism that’s tricky to pick (and encased in hardened steel, for good measure). We didn’t try to pick the SAF Lock, so we can’t speak to its pick-proof qualities.

Instead, we tried to cut it the fun way, by ruining a bunch of grinder discs and dousing ourselves in aluminum dust. As you’ll see in the above video, it’s a huge pain to destroy one of these locks with a 4.5- or 5-inch angle grinder. None of the material itself is difficult to cut—the grinder slid through the aluminum shell like butter and made short work of the hardened steel shackle—but there’s just so much material. A 5-inch grinder disc has little more than an inch of cutting depth before you run into the body of the grinder itself, so you can’t cut straight through. Instead, you have to cut away enough of the aluminum shell to fit the entire grinder through the shackle, a task that took us over an hour.

Akers told Bicycling that Altor set out to make a lock that could withstand 45 minutes of angle grinder cutting, so in that regard, the SAF Lock succeeds. A crucial stipulation on that claim (which Altor has identified in its marketing materials) is the size of the grinder. Portable 7-inch grinders exist and might make short work of the shackle, but those cost around 300 and tougher to disguise.

One cut isn’t enough to beat this lock, thanks to a dual-locking crossbar. Instead, two full cuts are required.

The SAF Lock is formidable and effective against angle grinders, but for real-world use, its practicality may be questionable.

First, any thief with a brainstem would likely give up trying to cut the SAF Lock and turn the grinder on whatever it’s locked to. Or worse, a thief just cuts your frame and makes off with everything else. Second, the shackle is too thick to go through a wheel, so the lock only protects your frame. In a high-theft area, that means your wheels and other components are still subject to thievery, and we’ve all seen that picked-apart bike frame locked to a post with nothing left but the crankset. Leaving your bike outside all day—the behavior for which the SAF Lock is designed—just isn’t a good idea if you live in a high-theft area.

That said, if you just want the beefiest lock on the bike rack, the SAF Lock is an unbeatable theft deterrent. It’s currently in the crowdfunding stage on Indiegogo, and putting your money down now takes 100 off the 300 list price.