The Strongest Bike Lock

If you’re looking for an unbreakable bike lock, then unfortunately I’ve got some bad news: no bike lock is unbreakable!

However if you keep reading I will introduce you to the next best thing: the 7 strongest bike locks money can buy.

But first a quick explanation. Every bike lock can be defeated if a thief has the right tools and enough time. The strongest bike locks just need more advanced tools and more time to break.

So when you buy the most secure bike lock you’re just reducing the number of thieves who’ll have the tools and the time to steal your bike.

It’s also worth noting that the strongest bike lock doesn’t necessarily mean the best bike lock for you...

As we’ll see: with great strength comes some compromise! The more secure a bike lock is, the heavier and less practical it is. Not to mention more expensive.

But if you live in a high risk area such as big town or city, and you ride a nice, expensive bike, then you’ll undoubtedly need a very strong lock. So check these out…

1. Kryptonite New York Fahgettaboudit: Strongest U Lock

The Kryptonite New York Fahgettaboudit Mini is without doubt the most secure portable bike lock available today. And arguably it’s the strongest bike lock full stop.

Kryptonite Fahgettaboudit Mini: Strongest Bike Lock

Kryptonite New York Fahgettaboudit Mini

My score:

Check price:

Shackle thickness:

18 mm


4.55 lb (2.06 kg)

Size (internal):

3.25 x 6"

(8.3 x 15.3 cm)

Kryptonite rating:


Other Security Ratings:

With a 18 mm shackle, it’s completely bolt-cutter proof. Not only from even the biggest, manual bolt cutters. But also from hydraulic bolt cutters!...

As I mention above all bike locks can be defeated. But the only way to cut the Fahgettaboudit is with an angle grinder...

And because it’s made from a super high quality MAX performance steel, cutting it with an angle grinder takes longer than any other bike lock.

It's worth noting that in the video above, the lock is positioned to make an angle grinder attack much easier (and therefore quicker). In the real world, you'd lock it lower down around the seat post or chain stay, where it would be much more difficult to access.

And don’t forget: it’s double bolted (locking on both sides of the shackle), so it needs to be cut twice to open it up!

Also, because it’s a mini u-lock, once you’ve secured your bike, there shouldn’t be any space inside the U shape which could be exploited by leverage attacks or filled with a small hydraulic bottle jack.

So it should be virtually immune to these tactics which are commonly used on bigger u-locks.

This extraordinarily high level of security is reflected in the ratings from the independent lock testers. Not only is it Sold Secure Bicycle Gold. It's also Sold Secure Motorcycle Gold which requires a higher level of security again. And it gets 4/5 stars from ART too.

But all this security does mean compromises elsewhere. It’s very heavy, weighing 4.55 lb (2.06 kg), which is about the same as 5.5 cans of coke. So carrying it around everyday could be an issue.

The Kryptonite Fahgettaboudit weighs the same as 5.5 cans of Coke!

And it’s small size means you won’t have loads of options when our looking for somewhere to lock your bike. You'll be limited to bike racks and railings.

However, if your circumstances are high risk this is a fantastic bike lock. Incredibly secure, it’s as close to unbreakable as you’ll get. And it achieves this while still being portable.

All in all: the Fahgettaboudit is the best choice if you need the very strongest portable bike lock. But if it’s too heavy, too small or too expensive then there are plenty of alternatives…

2. Abus Granit X-Plus 54 Mini: Strong and Light

The Abus Granit X-Plus 54 Mini [Amazon] is the small version of the ever popular Abus GRANIT X Plus 540, which I think is the best all round bike lock available today.

Abus GRANIT X-Plus 54 Mini

Abus Granit X-Plus 54 Mini

My score:

Check price:

Shackle thickness:

13 mm


2.65 lb (1.20 kg)

Size (internal):

4.25 x 5.51"

(10.8 x 14 cm)

Abus rating:


Other Security Ratings:

Also known as the San Francisco Lock (because it was specifically designed to fit around the city’s reinforced parking meters), the Abus 54 Mini is often overlooked when thinking about the very strongest bike locks.

Maybe because at first glance it doesn't look that tough. But that's what makes it such a great lock...

The shackle is only 13 mm thick. But it’s made from a very strong steel in a special parabolic shape that makes it immune to bolt cutter attacks.

Just like the Fahgettaboudit it’s double bolted and it’s small size means it’s very unlikely it could be defeated by hydraulic jack or a leverage attacks.

This level of protection is reflected in it’s security ratings. Like the Fahgettaboudit, it’s been awarded both Sold Secure Bicycle Gold and Motorcycle Gold. And it has a 3/5 star rating from ART.

So it's nearly but not quite as secure as the Fahgettaboudit.

Abus Granit X-Plus 54 Mini vs Kryptonite Fahgettaboudit Mini 

Where it resolutely beats the Fahgettaboudit is in weight. At 2.56 lb (1.16 kg) it’s almost half as heavy as the Kryptonite lock. That’s a much more manageable 3 cans of coke!

For me, the weight advantage of the Abus beats the security advantage of the Kryptonite, and if they are more or less the same price I would tend to go for the Abus. But that’s a choice you will make yourself based on your own priorities!

3. Kryptonite New York Standard: Strong and Big

The Kryptonite New York Standard [Amazon] isn’t quite the standard sized version of the New York Fahgettaboudit. (That would be the New York M18-WL which I’m excluding here because it’s really a motorcycle lock).

Kryptonite New York Standard

Kryptonite New York Standard

My score:

Check price:

Shackle thickness:

16 mm


4.35 lb (1.97 kg)

Size (internal):

4" x 8"

(10.2 x 20.3 cm)

Kryptonite rating:


Other Security Ratings:

But in terms of security it’s the closest a standard sized bicycle u-lock gets to the Fahgettaboudit. It “only” has a 16 mm shackle compared to the 18 mm shackle on the Fahgettaboudit. But it’s still Sold Secure Bicycle Gold and gets 4/5 stars from ART.

Kryptonite New York Standard vs Kryptonite Fahgettaboudit Mini

And even though the bigger size will give you loads more places to lock your bike, it’s still lighter than the Fahgettaboudit. So you win twice!

Weighing 4.35 lb (1.97 kg), of course it’s still very heavy (around the same as 5 cans of Coke). But you won’t find another standard sized u-lock offering this kind of security that’s any lighter.

So, if you want the very highest level of protection without sacrificing the number of places you’ll be able to lock your bike, the New York Standard is a great choice.

4. OnGuard Brute Mini: Strong and Cheap

The OnGuard Brute Mini [Amazon] is a mini u-lock just like the Fahgettaboudit. It’s double bolted and with a shackle that’s 16.8 mm thick, it’s also completely bolt cutter proof.

And while it’s not quite as secure as the Fahgettaboudit, it's always available at a much cheaper price!

OnGuard Brute Mini

OnGuard Brute Mini

My score:

Check price:

Shackle thickness:

16.8 mm


3.83 lb (1.74 kg)

Size (internal):

3.55 x 5.52"

(9 x 14 cm)

OnGuard rating:


It’s not actually rated by Sold Secure or ART. But don't let that worry you (unless your insurance policy requires an officially rated lock)...

It’s essentially the smaller version of the Sold Secure Gold rated OnGuard Brute STD (and has the same in-house security rating), so it's just as secure and I feel very confident recommending it here.

Again it’s significantly lighter than the Fahgettaboudit, weighing 3.06 lb (1.39 kg), which is about the same as 3.5 cans of Coke. So it may be a little more practical as well.

OnGuard locks sometimes have a reputation for poor reliability but as long as you clean and lubricate it now and again, you should be OK.

All in all this is a very strong lock. And since it’s usually much cheaper than other locks that offer the same level of protection, I’d say it was the best value high security bike lock around.

5. Pragmasis Protector: Strongest Stationary Chain Lock

Since over 50% of stolen bikes are taken from the owner’s home, how you secure your bike in your garden, shed or garage is really, really important.

And since you don’t have to worry about carrying your lock around, in these situations chain locks are generally the best option.

Why? Well, the very strongest chain locks are immune to certain types of attacks that can defeat even very secure u-locks...

For instance hydraulic bottle jacks and leverage attacks can’t really be used on a chain. So the very strongest chains are more secure than the very strongest u-locks.

Chains are also more practical at home. Their relative length means you can use one chain to secure two or more bikes.

And they’re much more suited to use with ground anchors, shed shackles and the other immovable objects you’re likely to be securing your bike to at home.

But as we already know: stronger bike locks are heavier bike locks. That’s just the way it is. And since chain locks are always heavier than u-locks, the strongest chains are really, really heavy!

Of course this won’t matter if you’re just using them at home. But just to be clear: these super secure chain locks are not for carrying around on your bike!

If you’re in the UK then the very strongest chain locks come from two independent companies Almax and Pragmasis.

Both offer chains with 16 mm links that are guaranteed to be bolt cropper proof. No: they can’t be cropped even by the biggest most powerful 42″ croppers.

Pragmasis Protector with Squire SS65

My score:

Check price:

Chain thickness:

16 mm


17.09 lb

(7.75 kg)


60" (150 cm)

Security ratings:

This means that the only way a thief is getting through these chains is with an angle grinder. And that would take a fair amount of time and would obviously make a fair bit of noise!

Both chains comes in a range of lengths with the well regarded Squire SS65CS Stronghold lock which has a 13 mm shackle that can’t be cropped either since the way it closes protects it from attack.

And of course, both chains are Sold Secure Bicycle Gold and Motorcycle Gold.

Which to choose? In terms of security they’re both about the same. They’re the very strongest bicycle chain locks you can buy. (Both companies offer even more secure, 19 mm chains but these are so heavy they might actually damage your bike, so are not recommended for bicycles).

I prefer Pragmasis simply because they have an admirable environmental policy. But that's the only reason!

If you’re in the US then you won’t be able to get the Almax or Pragmasis chains. In which case, the next best thing is the Kryptonite New York Legend chain...

Kryptonite New York Legend 1515

New York Legend 1515

My score:

Check price:

Chain thickness:

15 mm


15.95 lb (7.23 kg)


60" (150 cm)

Kryptonite rating:


Other security ratings:

ART 5 Stars

This is Kryptonite’s most secure lock: a chain with 15 mm thick links is secured by a padlock with a 16 mm shrouded shackle.

While Kryptonite don’t guarantee it can’t be bolt cropped, it would take a very skilled (not to mention big and heavy) thief to get through this chain. I’ve certainly never heard of it being defeated by bolt croppers.

That it’s Kryptonite’s strongest lock is reflected in the security ratings. Sold Secure give it Bicycle Gold and Motorcycle Gold. While ART give it 5/5 stars. And Kryptonite themselves give it a full 10/10!

It’s available in two lengths: 35.5" (90 cm) and 60.0" (150 cm). The shorter chain weighs 9.50 lb (4.31 kg) which is the same as 11 cans of coke. While the longer weighs 15.95 lb (7.23 kg) which is about the same as 18.5 cans of coke.

As I said, these are not locks to carry around on your bicycle!

However, if you’re looking for the very strongest lock available to keep your bike safe at home: it's a fantastic choice.

6. Kryptonite New York Noose: Strongest Portable Chain Lock

While in most cases u-locks are the best choice for portable security and chain locks are best for stationary security, there may be circumstances where you’d prefer to use a chain lock out in the street.

For example, maybe you find wrapping a chain round your seat post easier than dealing with flaky u-lock frame mounts. Or maybe you need the greater locking options a longer chain gives you.

In both of these cases, I’d usually suggest you look at folding locks before chain locks.

But even the most secure folding locks aren’t as strong as a good chain. And maybe you want to use one lock to secure your bike both at home and out in the street. In which case a really secure chain lock could be a good choice.

The problem with chains is that to be portable they need to be thinner. And as chains become thinner they become more vulnerable to bolt croppers. So, unlike u-locks there are no portable chains that can’t be bolt cropped.

However, a thick chain of high quality, hardened steel and a good locking technique that keeps the chain off the ground can make it very unlikely that anyone will be able to bolt crop your lock out in the street.

So the strongest portable chain lock is simply the thickest chain that’s still light enough to carry around on your bike every day. And for me that’s the Kryptonite New York Noose.

Kryptonite New York Noose 1275 strongest portable chain

New York Noose 1275

My score:

Check price:

Chain thickness:

12 mm


6.95 lb (3.15 kg)


30" (75 cm)

Kryptonite rating:


Other security ratings:

This lock features a chain with 12 mm thick links and a disc lock with a 14 mm shackle. While both can theoretically be bolt cropped, if you keep the lock off the ground you can make this almost impossible.

And since Sold Secure award it Bicycle Gold and ART give it 4/5 stars you can rest assured this is a very secure bike lock indeed.

Now usually a 12 mm chain that’s long enough to be practical would be prohibitively heavy. Far too heavy to carry around on your bike every day.

But since this lock uses a noose system that almost doubles the usable length of the chain, it can be shorter and therefore lighter while still remaining practical. I explain how this system works in my full review here.

Don’t think that this means the New York Noose is light! It’s available in two lengths 30.0" (75 cm) and 51.0" (130 cm). Only the shorter length is light enough to be portable.

And even then it weighs 6.95 lb (3.15 kg) which is the same as 8 cans of Coke and makes it significantly heavier than even the Fahgettaboudit!

So there needs to be a good reason to choose a portable chain lock over a u-lock. But if that choice makes sense to you then this is the strongest portable chain lock available and a really great lock for high risk areas.

7. Altor SAF: First Angle Grinder Resistant Bike Lock!

If no lock is unbreakable that's largely because no lock is angle grinder proof. As countless online wags will tell you of any lock: "an angle grinder will go through that in seconds, mate".

And they're not wrong. Even the Fahgettaboudit can be cut in less than a minute.

Notice that all these videos have the lock held tightly in a clamp rather than round a bike where it would move around and be much more difficult (and take much longer) to cut...

But that's not really the point today. The point is: an angle grinder will go through any lock quite quickly. 

And unfortunately with improvements in battery technology we're seeing more and more thieves using portable angle grinders to steal bikes out in the street.

So Altor have come up with a lock that while not angle grinder proof, will slow it down for long enough to make a thief give up...

Altor SAF: Angle Grinder Resistant

Altor SAF

My score:

Check price:

Shackle thickness:

80 mm

Internal shackle:

14 mm


13.2 lbs (6.0 kg)

Size (internal):

3.2 x 5.5"

(8 x 14 cm)

Size (external):

8 x 11"

(20 x 28 cm)

How have they managed this? The SAF features a pretty standard 14 mm shackle that double locks into a hardened steel cross bar.

But the whole thing is wrapped in an aluminum shell that keeps an angle grinder blade away from the shackle.

And while the angle grinder could (of course) cut the aluminum shell to get to the shackle, it's designed in such a way that this takes a long, long time. In one test it took over an hour, (plus several new blades and batteries)!

The Altor SAF has not been tested by Sold Secure or ART yet. And it's not clear how long it withstand a multi tool attack. But by effectively nullifying angle grinder attacks it deserves it's place in this list.

Now one thing I must stress: the SAF is absolutely massive. It weighs 13.2 lbs (6.0 kg). Which is the same as 3 Fahgettaboudits or 16 cans of coke!

And while the internal measurements of 3.2" x 5.5" (8 x 14 cm) are about the same as the mini u-lock Fahgettaboudit, the external measurements of 8" x 11" (20 x 28 cm) make it the bulkiest u-lock around!

So this is not a portable u-lock. And neither is it a u-lock that offers lots of flexible locking options. This is a lock to keep wherever you keep your bike overnight. And make sure you've got a secure immovable object that the SAF will fit around!

But as the worlds first angle grinder resistant bike lock it's a great leap forward in bicycle security!

Wrapping up

So these are the very strongest bike locks. They’re not unbreakable. Whatever anyone tells you: no bike lock is unbreakable (and there’s no such thing as a theft proof bike). But they’re as close as you’ll get.

Don’t forget of course that this security comes at a price. The strongest locks are often small, heavy or expensive. Some of them are all three!

But if you ride a desirable, high value bike in a high risk area then you need a super secure bike lock and these are the best you can buy.

With one of these locks and good locking technique you’ll know you’ve done the most you could possibly do to protect your bike.

If you’re not sure, I suggest you read my complete guide to finding the best bike lock for you.

This will show you the 3 simple steps that guarantee you find a lock that both adequately protects your bike and is practical and painless for you to use every day.

This page contains affiliate links, which means I may earn a small commission if you click through and make a purchase. You will not pay any extra. More details here.

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Last Updated on August 8, 2021 by Carl Ellis

Carl Ellis
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