LockJudge Strongest bike locks

8 Strongest Bike Locks: Uncuttable and Unbreakable

If you live in a high crime area or have a very valuable bike then you will need a bike lock that has the highest possible level of security available.

We have found the strongest bike locks available. These locks are as close to unbreakable and uncuttable as they can be.

Obviously, there is no such thing as a bike lock that can’t be cut, it’s just a matter of how long it will take and what tools you use.

The main aim of the strongest bike locks is to make cutting or breaking them so challenging, even with the best tools, that a thief will give up before they can steal your bike.

This also allows someone to call the police to stop the thief from stealing the bike. Which increases the risk of attempting to steal the bike and will stop a thief from even trying to steal the bike in the first place.

The strongest bike locks are not necessarily locks that are the strongest against lock picking. This is because lock picking is not a technique used by thieves very often.

So while the LockLickingLawyer’s recommended bike locks may be different from the ones we have here, rest assured these locks will provide you with the very best protection available.

How We Chose The Strongest Bike Locks

The locks on this list were chosen by finding the most secure bike locks in their relevant class. We did not choose them according to their price, the number of sales, or anything other than the level of security they provide.

All the locks here are in the highest security class or have a security feature that makes them unique.

If you want to know more about us and how we choose locks then you can read about us and our methodology here.

Angle Grinder Resistance

When it comes to measuring the security of a bike lock, resistance to an angle grinder is one of the most important measurements.

These days thieves are using modern portable power tools like portable battery-powered angle grinders to simply cut bike locks and this has set a high bar that bike locks need to defend against.

bike lock being cut with and angle grinder

This is why the thickness of the shackle is so important for each lock. This measurement shows the amount of material that will need to be cut through for a thief to steal your bike.

This gives us a guide to how long it would take to cut through with an angle grinder.

Grinder-resistant bike locks are very new but there are some coming to the market now. Check out this video of the best two available.

Cutting test of the two strongest bike locks, on the market.

Note: The material, grinder, physical placement, and other real-world factors have a big influence on how long a grinder will take to cut through a bike lock.

Types of Bike Locks

There are a number of different types of bike locks and they all have their benefits and drawbacks. U-locks are generally the strongest bike locks but this varies a lot.

Choosing the right type of bike lock is very important because not all locks will suit all situations. Some locks are better suited to be left in one place while others are built to be portable.

If you are not sure what type of bike lock you need then we have an article to help you decide the best type of bike lock for your needs.

Strongest Bike Lock

This is the top dog of bike locks. If you want to get a single lock that is simply the strongest bike lock you can get your hands on then go no further.

Whether it is bending, breaking, cutting, hitting, or any other attack this is the strongest bike lock that you can get.


LITELOK X3 strongest bike lock

The Litelok X3 is a thief’s worst nightmare. It is extremely hard to cut even with an angle grinder and will stop even the largest bolt cutters in their tracks.

On top of this, it has a nice large shackle so there is plenty of space to get around your bike frame and something worthy of being an anchor point for this lock.

In most situations finding a suitable anchor point that is stronger than this lock will be the hard part. But this is a good problem to have when the lock is no longer the weak point.

Why is this the Strongest Bike Lock?
We think the Litelok X3 is the strongest bike lock because of its cut resistance to bolt cutters and angle grinders. It has almost the same resistance as the Hiolok D1000 below. This lock also has awesome strength from twisting and bending attacks. All this together earns it the title of the strongest bike lock.

Barronium™ is the new material created by Litelok for use in their bike locks. They claim that it is a “super hard ceramic composite material”. This is most likely a mix of metal and ceramic beads that cause the blade of a grinder to chip and heat up as they are not designed to cut these types of materials.


  • Strongest bike lock available
  • Sold Secure diamond certified
  • Resistant to bolt cutters
  • Angle grinder-resistant bike lock
  • Twist and break resistant
  • Large size for use with bikes or motorcycles


  • Very expensive
  • Heavy


Weight2.1kgs, 4.6lbs
MaterialsShackle (Barronium™), Body (hardened fine-grain high-tensile steel)
Shackle Thickness19mm


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Uncuttable Bike Locks

The most common way that bikes are stolen is due to the lock being cut with bolt cutters or a portable battery-powered angle grinder.

Until very recently the only way bike locks have been able to deal with this is to simply make the lock extremely thick so that it takes a long time to cut.

Thankfully innovations in material science are allowing companies to make composite materials that can stand up to angle grinders by destroying the cutting wheel as it cuts the material.


strongest bike lock

The Altor SAF takes a unique approach to defense from power tools one that we have not seen employed on other locks to date.

The idea is that a normal 5-inch cutting disc will firstly get clogged and have difficulty cutting the material that the lock is made from, and second that the shackle is simply so thick that a normal cutting disc is not large enough to cut through far enough to compromise the lock.

What makes the ALTOR SAF so special?
The ALTOR SAF was one of the first bike locks that took on the angle grinder.

Before it was created, all locks were built with a focus on defending from tools like bolt cutters and hacksaws, but not really meant to put up a good fight to power tools.

The SAF really took on a new approach of trying to prevent an angle grinder from being able to cut into the lock deep enough to actually compromise it.

So many bike lock producers ever specifically tried to defend against the portable angle grinder as these types of portable tools are quite a new thing and it is a very difficult thing to try to defend against. That was until locks like the ALTOR SAF hit the market.

While the protection this lock provides is undeniable the lock itself is a beast of an item. It is not the lock you want to be carrying around with you on your bike due to its immense size.

Its size serves as another benefit for this lock, many thieves are likely to simply walk past because of how FREAKING CHONKY THIS THING IS!

The unique design and appearance of the Altor SAF lock can act as a visual deterrent for potential thieves. When they see the lock, they may be less likely to target the bike, knowing that it will be difficult to defeat.


  • Ultra-secure bike lock
  • Angle grinder-resistant bike lock
  • Impossible to cut with bolt cutters
  • Twist and break resistant


  • Not portable
  • Very heavy
  • Difficult to use due to the size and weight of the lock
  • You may also have to buy a portable lock


Weight6.2 kgs / 13.7 lbs
Lock CoreDisc-detainer
MaterialsAluminum outer shell over hardened steel shackle
Shackle Thickness14mm (inner), 80mm (outer)


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Hiplok D1000

history of locks

One of the latest locks out there is the Hiplok D1000. A unique-looking bike lock with a square shackle profile this lock is on the cutting edge (excuse the pun) of material science in bike locks.

Ferosafe is the material that makes this lock special. It is a composite material of metal and ceramic, the idea of this is that angle grinder discs used for cutting metal are not designed to cut ceramic so having a composite means that a normal grinder will not be able to cut it easily.

How is this an uncuttable bike lock?
This lock has been tested over and over again with angle grinders and while it is still possible to cut it, the amount of time it takes and the difficulty in doing it means that it will almost never happen.
Cut times for this lock regularly take more than 20 minutes and we found the same. Where other trusted locks can be cut in under a minute this lock provides security that is second to none.

Under all tests, this does prove to be one of the most cut-resistant bike locks you can buy. So if you are looking for an uncuttable bike lock, then this is definitely one that you should consider.

It has a nice soft rubber coating around the whole shackle and body of the lock so you can use it without any worry of it damaging your bike.

While it is smaller overall than the Litelok X3, this does make it easier to carry and lighter too. So if you want to be carrying it around and don’t need the extra size then this could be the best option for you.

The shackle of this bike lock has a square profile, which makes bending and twisting the lock much harder as the shackle will not rotate inside the body of the lock, further adding to its overall strength.


  • Under 2kgs (4.2lb) in weight
  • Resistant to bolt cutters
  • Angle grinder-resistant bike lock
  • Twist and break resistant
  • Lifetime Warranty


  • Very expensive
  • Smaller locking area than Litelok X3
  • The mounting system is not as good as other bike locks


Weight1.9kgs, 4.2lbs
Lock CoreBrass automotive style core
MaterialsShackle (Ferosafe graphene composite), Body (hardened steel)
Shackle Thickness20mm


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Strongest Bike Cable Lock

Bike cable locks are usually something to steer clear of. This is because in most situations they are quite easy to cut and very cheap ones can even be cut with simple wire cutters or a pair of pliers. This makes them completely unusable for almost any purpose.

That being said, we have found a cable lock that is actually worth looking at and will provide some real security for your bike, e-bike, scooter, or even motorcycle.


history of locks

If you are looking for something that’s easy to carry, and easy to use while providing some of the best security you can get then this is the lock for you.

While this is not as secure as the angle grinder-resistant bike u-locks above it beats them by miles in some other aspects.

This lock is so much easier to use than a u-lock, it is flexible and easily latches together so if you need to lock your bike to a larger pole or something with an odd shape then it’s easy to do.

It is easier to carry. If you are thinking of wearing this around your waist while you ride then you will almost not know it’s there. This is a big selling point of this and other locks by Litelok, you can wear them comfortably for ease of transport.

You can also easily attach it to your bike frame with the mounting straps, so no matter how you carry it you will not really notice it.


  • Flexible for ease of use
  • Very soft outer coating to protect your bike
  • Bolt cutter resistant
  • Brute force resistant
  • It has some angle grinder resistance


  • Will not resist an angle grinder for more than 5 minutes


Weight1.9kgs (4.2lbs)
Lock CoreDisc Detainer
MaterialsHigh tensile steel core with steel sheath
Shackle ThicknessUnknown


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Strongest Folding Bike Lock

Folding locks usually have problems with thin cuttable arms and rivets that can be broken with different tools.

Thankfully the strongest folding bike lock has managed to address these issues to give us one of the most capable folding locks currently available.

SEATYLOCK Foldylock Forever

history of locks

As far as folding locks are concerned the Foldylock is the best on the market, with thick hardened steel arms and strong well-protected rivets in the joints, the Foldylock Forever manages to overcome the issues that plague so many folding bike locks.

It is exactly these features that earn this lock the title of being the strongest folding bike lock. With links that are just as thick as a 14mm round shackle, it will provide a high level of cut resistance to bolt cutters and gives some resistance to a grinder.

Where this folding lock really shines is in the protection of the pins at each join. This is normally a weak point for many folding locks as bolt cutters or nut splitters can get in between the links and break the pins.

The Foldylock Forever protects from this by having a washer in between the links that recess into each link meaning that nothing can get past it to damage the pin.

Finally, the locking mechanism is a large hardened steel cylinder so it is safe from many types of attacks.

The Forever also has a nice soft outer coating so you don’t need to worry about it scratching the paint on your bike and the mounting case holds the lock tightly onto the frame so that there is no rattling or noise when you are riding.

This is perfect for someone looking for a high level of security, but something easier to use and lighter than the biggest locks above.

This is the best option if you are after the strongest bike lock for a road bike as this one is small and light enough to fit on the frame of most road bikes.


  • No noise while riding
  • Resistant to bolt cutters and other cutting hand tools
  • Cheaper
  • Stronger than many U-locks


  • The lock core is not as pick-resistant as other options
  • Not very resistant to an angle grinder


Weight1.76 kg (3.88 lbs)
Lock CoreAutomotive Wafer Lock
MaterialsHardened Steel
Shackle Thickness6.7mm (equal to 14mm round shackle)


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Heavy-Duty Bike Lock

After a heavy-duty bike lock? Do you want a lock that will put up with the weather, getting a beating, and anything else while operating as it should?

We have looked long and wide to find a bike lock that will put up with anything, getting thrown around, being out in the weather, and anything else you can throw at it without missing a beat.

And this is what we found for the category of heavy-duty bike locks.


history of locks

The ABUS Granit XPlus 540 has been around for a couple of years now but it is still a great heavy-duty bike lock.

It has a thick square shackle, a large locking area for use around larger poles and even around motorcycle wheels, and a great locking core with high security.

The main area of concern is that it doesn’t have the greatest angle grinder resistance but it will stop bolt cutters in their tracks.

The shackle will also put up with any type of breaking, pulling, or twisting attacks that a thief can throw at it.

Thanks to the square shackle that helps stop the rotation of the shackle in the body and the ball bearing locking it are strong enough to stop any physical attack someone could manage on the street.

While it will put up a good fight against an angle grinder the XPlus 540 will still be able to be cut in under a minute as it doesn’t have any special protection against a grinder.


  • Very strong bike lock
  • Heavy duty construction
  • Resistant to bolt cutters
  • Resistant to all physical attacks
  • Great locking core


  • It is not very resistant to angle grinders


Weight1.7kg (3.7 lb)
Lock CoreABUS XPlus Lock Core
MaterialsHardened Steel Shackle and Body
Shackle Thickness13 mm square (14.5mm round equivalent)


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Heavy-Duty Bike Chain Lock

If you would like something more flexible and storable then a bike chain might be the way to go for you.

Bike chain locks are usually much easier to use and will fit around more things, they are also harder to cut with an angle grinder as they are flexible and don’t provide a hard surface to cut against.

The main downside of a chain lock is that in general, they are much heavier than other locks of similar security.

Kryptonite EVOLUTION 4 1090

Kryptonite Evolution Series 4 1090

This is one of the strongest bike chain locks on the market. The lock core has a hardened steel case that surrounds the internals of the lock making it very hard to get into.

I personally use this as my bike lock for several reasons, one is that I chose this lock because it was a bike lock recommended by the LockPickingLawyer. It is also very hard to attack with an angle grinder because the links are not easy to hold onto to be able to cut them.

The lock is easy to use in general and can even be used for two bikes if you need it. The lifetime warranty is great and even after having this out in the weather for more than two years it still works like it’s new.


  • Very secure bike lock
  • Hard to cut with an angle grinder
  • Can be folded up quite small for storage


  • Heavier than other options
  • Not as cut-resistant as other bike locks


Weight2.77 kgs (6.10 lbs)
Lock CoreDisc-detainer Cylinder
Materials3T Manganese Steel
Shackle Thickness10mm


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Vomit Inducing Bike Lock

This lock deserved its own place in this list because it has a very unique way of deterring thieves…

If you have ever wanted to get back at a bike thief then having one that causes them to vomit because they tried to cut it open is a great option.

The only issue with using a lock like this is the legal aspect of it. Some countries may be fine with this, but there are some places where this could land you in some trouble.

SkunkLock V2

Skunklock bike lock

If you want to play a role in karma against a thief that is trying to steal your bike then you might have found the right product.

The skunk lock is a very capable and strong bike lock without its secret weapon at the core.

With a thick hardened steel shackle, strong lock core and large hardened steel lock body this lock is a very tough nut to crack before you consider that it will cause an attacker to throw up their lunch all over themselves trying to open it by way of force.

This also means that you don’t have to worry about the gas being released by accident as it’s kept in the core of the shackle with thick hardened steel all around it. Meaning that someone will only discover it if they are trying to cut their way through the lock.

Note: There may be legal implications that you should consider if you want to use this bike lock.


  • It’s just awesome…
  • A very unique way of protecting your bike
  • Double bolted shackle


  • Possible legal issues associated with using this lock
  • No independent security ratings


Weight2.2 kg (4.88 lb)
Lock CoreDisc Detainer
MaterialsHardened Steel
Shackle Thickness19mm


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Additional Tips and Advice

Here are some additional tips and advice for using these locks. This is important because once you have a lock that someone can’t cut then maybe they will start looking at other ways to get your bike.

Lock Placement

Always place your bike lock around the back wheel and the upright tube in the frame that holds the seat post.

Placing the lock here will make it much harder to get to and harder to cut as it has a lot more delicate items in it that a thief will not want to damage while cutting the lock.

Anchor Point

What you anchor your bike to is just as important as the lock that you use to secure it.

Simply speaking, for someone to steal your bike they either need to cut the bike (and they won’t do that as it defeats the purpose), cut the lock, or sometimes more simply just cut what the lock is attached to.

If you attach an extremely strong lock to a thin fence then it doesn’t matter what lock you use as a thief will just cut the fence and take your bike with the lock attached.

Once they have the bike somewhere else they can take their time to remove the lock.

Use a Bike Registration Service

Bike Registration Service diagram

Bike registration services work by registering your bike on a central database that allows anyone including law enforcement to look up any bike registered on the database to verify the original owner.

This means that if your bike is stolen then it can easily be identified and reunited with its owner.

Registration is a big deterrent to thieves as it makes a bike much harder to sell and also increases the chances of them getting caught with a stolen bike.

The UK has the bike registration service BikeRegister.com but there is also BikeIndex.org for the US and other areas around the world.

What is the hardest bike lock to pick?

The LITELOK X3 is one of the hardest bike locks to pick as it has a very high-security Abloy Sentry lock core.

The Abloy Sentry lock cylinder has the highest lockpicking difficulty with a rank of black belt from the lockpicking community.

The pick resistance of this lock and its overall security has earned it the title of the strongest bike lock, and you can read more about that here.

Is there a bike lock that cannot be cut?

The simple answer is no, all bike locks can be cut with enough time and perseverance. But some locks, like the LITELOK X3 and Hiplock D1000, are so hard to cut through that a thief will not be able to do it in a reasonable time.

If a lock can survive long enough then either the thief will give up, or the police will arrive to stop them from stealing the bike.

This is why it’s not simply if a lock can be cut, but how long it will take.

What is the best bike lock for anti-theft?

The LITELOK X3 and Hiplock D1000, are currently the most secure bike locks that you can buy.

They are the only locks that can keep a bike secure from an angle grinder for a reasonable amount of time.

What locks can bolt cutters not cut through?

Any hardened steel bike u lock or chain that has a diameter above around 10mm will be extremely hard, if not impossible to cut through with bolt cutters.

Locks larger than 18mm will not fit into the jaws of even the largest bolt cutters so it will not be possible to cut them at all.

What locks cannot be broken?

Most high-quality u locks and many chain locks cannot be broken as they are simply too strong. When looking for an unbreakable bike u lock, try to find one with double locking on the shackle as this makes them stronger than single locking.

Also, u locks that have a thick shackle (greater than 14mm) will be extremely resistant to breaking. You can find the strongest bike locks in this article.

What do Lock Pickers Think?

Edit: Have a look at this video from LockNoob that has summed up almost exactly what we have said in this article.


With so many bike locks out there it can be hard to find one that will give you the level of security promised. This is why we created this list of the strongest bike locks.

Angle grinders are now the tool of choice for bike thieves so securing your bike, especially if it is an expensive e-bike, has changed significantly.

A basic bike lock is no longer sufficient and we are now seeing the rise of angle grinder-proof locks. First with the Altor SAF, and now the much lighter and more practical LITELOK X3 and Hiplock D1000.

It is now more important than ever for the lock industry to move forward with higher security locks to cope with the rise in the use of these new tools by thieves.

We hope this article has helped you find a lock to keep your bike safe and if it has please share it with someone else who could also benefit from this information.

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