Best bike lock 2024: Strong, safe bike locks tested in lab conditions

Since we began testing the best bike locks in 2007, we’ve reviewed more than 100 bike locks.

Our latest test included a selection of the best D-locks (also known as U-locks), foldable locks and chain locks for cyclists, at various prices.

To find out which are the best bike locks on the market, I tested 12 locks in lab conditions and considered everyday practicalities such as ease of use and weight. I also compiled key statistics for each lock, including weight and security rating.

The Litelok X1 proved to be the best bike lock on test. The Abus Bordo Granit was the best portable bike lock, the Hiplok DXF was the best-value bike lock and the Litelok X3 was the toughest lock on test.

Keep reading to find out how we tested the latest bike locks and what they scored, or skip to the end of this article to read our buyer’s guide to bike locks.

I took our line-up of bike locks to Abus’ test labs in Rehe, Germany. The locks were subjected to five gruelling tests to simulate attacks from bike thieves and day-to-day use.

To test resistance to corrosion, each lock was subjected to 168 hours in a climate chamber (to ISO 9227 standards). This is the equivalent of 10-12 months of outdoor use in a salty air environment.

Up next was a tensile-pulling rig. This simulates the bottle-jack approach to breaking locks, where a hydraulic bottle jack is used to push apart the two sections of a lock. The hydraulic test rig pulls on both parts simultaneously and has more than 7 tonnes of pulling power.

A torsion test, to simulate a crowbar, followed. The rig can twist a lock to massive torsional pressures, the equivalent of using a crowbar of more than 1.5m and with a World’s Strongest Man contestant doing the crowing.

Next up was a hydraulic jaw that cuts like a bolt cropper. It’s capable of more than 250 Kilonewtons (kN) of pressure.

I then tested the angle-grinder-resistant bike locks with the grinder test. The non-armoured locks can all be cut relatively quickly with a grinder. For example, a 14mm-diameter steel shackle takes 22.3 seconds to cut, while an 8mm bar of a folding lock will take 8 seconds.

Litelok's X1 proved to be the best bike lock on test.

Its 13mm-diameter shackle is slim by armoured-lock standards, which helps keep the weight down to 1.75kg. The steel is protected by a fused-on material called ‘Barronium’.

The twist-and-go frame mount takes up a fair amount of space within your bike frame. It comes with a protective neoprene pouch if you want to slip it into your bag instead.

The lock proved impressive in testing. It resisted the bottle jack test for 96.9kN of force, far beyond what your average car jack could produce, while its bolt-crop resistance is good at 107.3kN. Its crowbar resistance requires 2,218Nm of force, making it the most resistant lock to this attack.

In the corrosion test, there were deposits on the lock body, but it still operated perfectly. It was as good as new after a quick clean and lubrication.

When I tried to cut it with an angle grinder, it took 4min 38secs (including disc changes) to cut through one side of the X1’s shackle, which exceeds its premium rivals and the Sold Secure Powered cycle Diamond rating.

The Granit Superxtreme 2500 is Abus’ first angle-grinder resistant lock, with a hardened steel shackle, armour plating and tungsten carbide, encased in a solid plastic shell.

The flush fitting means it’s rattle-free and the bracket holds the heavy lock securely. The available locking space is ample for road, gravel, and most mountain and electric bikes.

It uses Abus’ highest-grade XPlus lock mechanism, which can resist hammers and drills.

On the pull test, it took 74.9kN of force before one side of the lock ‘popped’. The dual-locking design means if the lock was broken you still couldn’t separate the shackle from the lock.

Bolt cropping took 132.8kN of force. In the crowbar simulation, I measured 1,964kN of twisting force before the lock popped, which would snap the bike or break whatever the bike was locked to.

To cut the lock with an angle grinder would take 12 minutes and 30 seconds – and you would need five cutting discs. You would also need a hacksaw and hammer to get through the hardened plastic, which would become molten with the heat of an angle grinder.

The Granit Superextreme stood its ground in our corrosion test, retaining full usability after 168 hours.

The Hiplok D1000 uses Ferosafe metal, which is resistant to diamond-carbide-tipped drill bits and angle-grinding discs.

The oversized U-shackle is 20mm in cross-section. Cleverly, it’s also square where it fits into the lock body, making it resistant to twisting forces. This bears out in testing: the twisting simulation required 1,954Nm to pop the lock, making the D1000 a tough cookie.

Its internal space is smaller than most of its rivals, but it can still comfortably lock a road bike.

With the pull test, it resisted for an impressive 34.3kN of force. Its bolt-cropper resistance required a massive 196.2kN, making it the toughest lock to sever manually in the test.

The locking mechanism is dual-sided, with twin bolts intersecting the U-shackle to hold it in place. That means you’ll need two cuts to break it free.

The lock faired well in our angle-grinder test. It would take 6 minutes and 6 seconds to cut through the outer material – which gums up cutting discs – and the Ferosafe core.

It retained functionality after the corrosion test.

The X3 is Litelok’s toughest anti-angle-grinder bike lock, meeting the highest Dutch ART4 standard, alongside both of Sold Secure’s Diamond standards.

It's like a beefed-up X1 with a similar high-tensile steel shackle and Barronium fused to the core to wear down angle-grinder discs.

The oval shackle on the X3 is thicker than the X1’s, while it’s more difficult to twist than a round shackle. The lock mechanism on the X3 is an Abloy Sentry lock cylinder that’s more commonly found on high-security doors for the defence and mining industry.

The X3 withstood a massive 79.8kN in the pull test, besting all of its rivals, apart from the cheaper X1 model. Its bolt-crop resistance of 111.6kN is similarly impressive, only outdone by Hiplok’s U-locks. The X3 withstands 1,961kN in the twisting test.

In angle-grinder test shows it would take over 12 minutes to cut through one side of the lock, requiring four cutting discs. You would then have to repeat this on the other side, all while creating a loud 115dB of noise.

The lock ceased to function after 120 hours of our corrosion test, so maintenance and lubrication is essential.

Squire's Stronghold D16 Max features a 16mm-diameter Boron steel shackle that’s reinforced with a proprietary anti angle-grinder surface.

Its locking mechanism is a high-security six-pin key cylinder with anti-drill, anti-pick and anti-bump technology and more than 500,000 key combinations. It comes with two keys and cannot be copied without the personal key card.

The lock’s generous sizing means it fits most bike types, while the shackle has a thick rubbery coating to prevent frame dings.

Under the pull test, the lock resisted until 54.3kN of force – way beyond what an average bottle jack can produce. The shackle resisted an impressive 106.3kN of force in our bolt-cutter simulation.

The angle grinder test showed it would take just under 12 minutes to cut through both sides of the lock. That’s a long time for a thief to be making the amount of noise and disruption an angle grinder brings.

There were signs of corrosion after 120 hours and by 144 hours the lock mechanism had stopped working properly.

The following locks scored fewer than four out of five stars in testing, but we have included them here for your consideration.

The Abus Bordo was the first folding-lock design and it proved to be the best portable bike lock on test.

Rated to Sold Secure Gold, the Bordo has hardened steel plates, linked with domed rivets and a heavy-duty lock mechanism. It packs down to a compact 190x70x40mm package inside a rubberised case with Velcro straps to attach to your bike.

The Bordo had mixed results in testing. The flexible bar design makes it difficult to bottle jack and crowbar attacks are similarly awkward, but its 5.5mm plates can be cut with an angle grinder in 6.8 seconds. It sailed through the corrosion testing with full operation and few signs of rust.

The DXF is Hiplok’s original DX compact U-lock but with a clever speed-loading frame-mounting bracket and prongs to fit it to your belt.

The shackle is broad at 8.5cm, making it a good close fit through the rear wheel and in front of the seat tube of a road bike, and awkward to break. The downside is you might struggle to lock a mountain bike with it.

The DXF performed fairly well in testing. It withstood twisting forces far beyond what an adult could exert with a crowbar and 183.5kN of pressure in our bolt-cropper test.

It only sustained 27.6Nm of force in the pull test, but its compact shape makes it practically impossible to fit a bottle jack in the lock. The lock also cleared the corrosion test, retaining functionality.

However, it only took me 22 seconds to cut with an angle grinder per side.

The Core Flex uses Litelok’s Boaflexicore+ material, with 200 strands of high-tensile steel wrapped in an eco-rubber casing and a flexible mesh. These components aren’t that strong but together they prove impressively tough.

The 75cm length is long enough to fit most bike types. It's wearable around 28- to 44-inch waists thanks to an extending strap. You can also wrap it into a loop and mount it to your frame.

The lock mechanism can withstand 29.8kN of pulling force. It also passed the bolt cropping test because the rubber and mesh make it hard for hydraulic jaws to gain purchase and the steel core compresses rather than cuts.

The Core Flex can be cut with a hacksaw in 52 seconds and an angle grinder in 13 seconds.

The lock was operable with little sign of corrosion after our test.

The Squire Stronghold FL/850 is similar to the Abus Bordo. The lock uses Boron steel plates coated with a soft-touch plastic coating to protect your bike.

The six-pin lock mechanism is said to be drill- and pick-proof and has more than 500,000 key combinations. The lock barrel is housed in hardened steel, with the key slot protected by a thick rubber coating.

Like other folding locks, the Stronghold proved difficult to pull or crowbar open, resisting up to 144.5kN in the hydraulic jaw test.

You can cut the bike lock in 36 seconds with a tungsten-bladed saw and 4.7 seconds with an angle grinder.

In the corrosion test, the lock showed signs of corrosion after 120 hours and was seriously rusty by the end, even if it was still just about functional.

The Abus Ultimate 420 is the most affordable lock on test, although it still meets Sold Secure’s Gold standard.

The lock is finished with a frame-protecting coating and a chunky robust cover over the steel lock-barrel body. It comes with Abus’ rock-solid, rattle-free USH frame bracket.

The lock can withstand high forces. It handled 25.4kN of force before bursting in our pull test and the 13mm steel took 72.6kN of force from our hydraulic jaws.

It didn’t fair so well in the crowbar test, so fill as much of the shackle as possible when using this lock. It’s available in a 230mm length, but the 170mm version will fit around the wheel and frame of most bikes.

The Ultimate 420 is no match for an angle grinder. It took less than a minute to cut through both sides. It did, however, sail through the corrosion test.

Squire’s Chainlok is intended to bridge the gap between wearable convenience and tough security. The lock is made from 10mm-diameter, hardened, square alloy steel chain links wrapped in a thick neoprene cover.

The patented lock mechanism uses a dimpled key that you push rather than turn to open. The mechanism also means multiples of the Chainlok can be linked to loop around more bikes.

The flexible nature of the chain means a pull test isn’t viable – and a crowbar attack will simply turn the chain back on itself.

Bolt croppers are normally a chain lock’s undoing, but the Chainlok withstood 66.4kN of pressure from the hydraulic jaws before breaking. The real-world equivalent would be straining on a 3-foot-long set of bolt croppers for 4 seconds per side.

After 120 hours in our corrosion test, the lock had limited functionality. At 144 hours, the mechanism ceased to function.

The Hiplok Switch weighs 935g and can be holstered in a clever bottle-cage boss mount, making it a convenient option, but only for short stops. This is because the Bronze-rated lock is easily cut or pried apart.

It withstood more pressure from the hydraulic jaws than some locks on test, but it’s not as strong as Squire and Abus’ equivalent folding-lock designs.

In the crowbar simulation, it took 338Nm of pressure to pop one of the rivets. That’s the lowest of our folding-lock options, although that was no surprise because it’s a lower-rated lock at a much lower price.

The Switch is excellent against corrosion, taking the full 168 hours without hindering the lock’s operation or showing much sign of corrosion.

In all, the Switch is a neat short-use lock that’s convenient but in no way a high-security option to lock your bike all day.

The table above shows the full results of my testing at Abus' test labs.

Certain tests did not apply to some of the locks. The pull test doesn't work with folding or chain locks. The hydraulic jaws weren't compatible with the rubberised cable core of the Litelok Core Flex.

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There are three main types of bike lock: D-locks, folding locks and chain locks. We explain what they are and their best application.

The D-lock, or U-lock as it is alternatively known, is the classic bike lock. The design consists of a big shackle and toughened crossbar with the lock mechanism built in. It has been around for years and it’s really just a super-sized padlock.

The benefits are the strength for its size and relative portability. The downsides are the slightly awkward shape if you want to lock more of your bike into it. You’ll want to add in an accessory cable or second lock to cover everything.

Sometimes, you need a lock that’s more portable than a D-lock or chain, but one that’s stronger than a simple cafe stop cable lock.

If you want a combination of lightweight, portability and toughness that you can trust for shopping stops and long lunches, a folding bike lock might be for you. The best folding bike locks are also suitable for securing touring bikes and bikepacking bikes for short periods.

Bike chain locks are heavy-duty and good for locking your bike to hard-to-reach points.

These locks are fairly heavy, so you won't always want to be carrying them around. But they're a good additional lock if you're leaving your bike locked up outside for extended periods.

The first thing to know about bike locks is no design is unbreakable. Armed with the right tools and knowledge, someone who really wants to steal your bike will be able to, no matter what you lock it up with.

Whether your pride and joy is one of the best road bikes or mountain bikes, it's unwise to ever leave it unattended outside – even secured by the best bike lock. The temptation could be too much to a thief.

What you can do is deter the bike thief looking for an easy steal. With that in mind, one of the best bits of advice we can give you, after many years of busting and picking locks in our tests, is to use two locks of different types and brands.

If a thief is adept at picking a certain type of lock and has the tools to do so, it’s less likely they will also have the tools or the knowledge to pick a completely different type.

Two budget locks that are wildly different in style and key/lock-cylinder types are sometimes better than just one expensive lock.

Here's a breakdown of all the key lock lingo

Sold Secure is an independent industry lock tester that provides a rating for bicycle locks.

Locks with a Sold Secure Diamond rating offer some of the highest levels of security available and are often good performers in strength tests.

The company doesn't have to give a rating, meaning it can fail locks it believes are not up to scratch, so seeing the label is a good indicator that the lock you are looking at is secure.

Investing in one of the best bike locks is an ideal first step to stopping your bike being stolen, but there are also other things to bear in mind when locking your bike up to make sure it stays safe:

You can read more tips in our article on how to lock a bike properly and how to improve your bike shed security.

There are several places you can put a lock while riding your bike.

Many of the best bike locks will come with a mount. These are intended to attach to your bike frame. It's a good idea to use the mount to hold the lock in the front triangle of the bike.

You can affix the mount to another part of your bike, if your bike's front triangle is obstructed by bottle cages and water bottles. Make sure it doesn't interfere with any moving parts or limit manoeuvrability.

You can always carry a bike lock in a pannier bag or rucksack. Some of the best cycling backpacks will have pockets for storing a bike lock, so it doesn't interfere with or damage your other possessions.