SkunkLock: the bike lock that bites back!



My score:

Check price:

Shackle thickness:

24 mm


3.92 lb (1.77kg)

Size (internal):

4.25" x 9.0"
(10.8 x 22.9 cm)


Chemical Attack!

Other Security Ratings:


Many new products claim to be unique. But very few really are. However, I can confidently say that the SkunkLock is the only bike lock in the world that will defend your bike by attacking the thief that’s trying to steal it!

Yep. Any thief that manages to break through the shackle of the SkunkLock, will be met with a cloud of noxious, vomit inducing gas, that’s likely to drive them far away from your bike, as fast as possible.

Now, once you’ve stopped cheering, sit back and relax, because there's a lot to think about here...

Unboxing the SkunkLock

If the SkunkLock is as hard to get through as its packaging, it will be hard to beat!

There's lot of questions to ask. And in this review I hope to add some clarity. How secure is it? How easy is it to carry around on a bike? How easy is it to use? And is it even legal? But, first things first...

How secure is the SkunkLock?

As a general rule, I only review bike locks that have security ratings from either Sold Secure or ART. But the SkunkLock has neither. And as far as I understand, there's no plans to submit the lock for testing and certification either.

To be honest, I’m not sure how we could judge whatever rating the SkunkLock received anyway. Because it doesn’t work like a regular bike lock...

SkunkLock unboxed

The SkunkLock isn't like any other bike lock!

Regular bike locks offer two distinct layers of security: a psychological layer and (a much more important) physical layer.

The psychological layer is all about how tough the lock looks. If it looks strong enough, then many thieves won’t even bother messing with it. The physical layer on the other hand, is all about how tough the lock really is, (how difficult it is to break it open).

With regular bike locks, if a thief overcomes the psychological and physical security of your lock, they will almost certainly ride away with your bike!

But SkunkLock adds another layer of security. If a thief does compromise the SkunkLock, that’s not the end of the story. Because a cloud of noxious gas will hopefully drive them away without your bike!

Warning on SkunkLock shackle

The SkunkLock's shackle is full of noxious gas

Since Sold Secure and ART only measure how hard it is to break a lock open, they would discount this extra layer of protection, which would lead to a rating that doesn’t fully recognise how well the SkunkLock protects your bike.

That’s presuming that they’d be prepared to test a lock that expels noxious gas the first place!

We of course, are not bound by such constraints! So let’s look at those three layers of security in a bit more detail.

1. Psychological Security

Visually, the SkunkLock is a beast! It's got a a 24 mm shackle, a 43 mm thick body, and it weighs 3.92lb (1.77kg). It certainly looks very imposing and secure.

Obviously, psychological security is very much secondary to how secure it really is (physically). But we shouldn’t discount the number of thieves that will leave it alone, just because it looks tough.

2. Physical Security

With u-locks, the most important thing to consider (in terms of physical security) is usually the shackle thickness. But this is also a bit complicated with the SkunkLock!

That’s because the shackle is actually hollow to accommodate all that nasty gas. So, the full diameter of the shackle is a whopping 24 mm. But 5 mm is plastic casing and 11 mm is hollow space.

This leaves 8 mm of protective, hardened steel. But that’s 8 mm of steel formed in a tube, so the walls of the tube are 4 mm thick.

SkunkLock shackle measurements

How the SkunkLock shackle measures up!

Manual bolt cutters don’t have jaws wide enough to fit around such a thick shackle. Hydraulic bolt cutters are a different story, of course, and would crop this (and most other locks) easily. And the shackle could also be sawn through (slowly) or cut with an angle grinder (quickly).

My main concern would be a leverage attack with a scaffold pole other long piece of metal. The SkunkLock shackle locks on both sides, so it’s unlikely to pop open. But the hollow shackle might deform to such an extent that lock becomes unusable.

Now, it goes without saying, that a bike lock with a hollow 8 mm shackle won’t be as secure as a bike lock with a solid 18 mm shackle. But locks with solid shackles won’t spray you with vomit inducing gas if you cut into them!

What the guys at SkunkLock have done is make compromises to the physical security of their bike lock in order to add this extra layer of “attack security” (the gas). 

They would argue that it doesn’t matter if your shackle is 18 mm of solid steel or 8 mm of hollow steel. Since an angle grinder will tear through both of them, more steel (more physical security) isn’t the answer.

They would say you need something else. Hence the SkunkLock’s gas attack!

Double locking shackle

The SkunkLock shackle locks on both sides for extra security

To be honest, I’m entirely unconvinced by the argument, (which you’ll hear across the internet), that portable angle grinders render all bike locks pointless, (for reasons I won’t go into here, but should be obvious).

However, it is undoubtedly true that an angle grinder can defeat any bike lock. And there are several other tools that will defeat most locks.

So what the SkunkLock is essentially offering, is a way to save your bike, even when your lock is defeated...

3. Gas Attack Security

So how does the SkunkLock’s extra layer of protection work? Inside the hollow shackle there’s a compressed, noxious gas that is very unpleasant and potentially vomit inducing.

And if a thief penetrates the shackle, this gas will be expelled out, towards the thief...

Cue: surprise, gasping revulsion and possibly vomiting. Contrary to what you may have read, the gas isn’t pepper spray (although some versions of the lock do contain capsaicin which is used in pepper spray).

The gas, is in fact, formulated from food grade chemicals (think rancid butter, parmesan cheese and vomit). So it won’t cause permanent harm to the thief. But it's designed to be so unpleasant, that in high concentrations it will induce vomiting!

And the idea is, that this extremely unpleasant experience will cause the thief to flee without your bike!

SkunkLock warning label

The SkunkLock makes it very clear that it's dangerous to tamper with!

Now, hands up, I’ve not yet cut the SkunkLock to test just how aggressive and unpleasant the gas is. And to be honest, I’m a bit wary of trying at the moment (which shows the SkunkLock is doing it’s job already). 

But I’d imagine, that how well it works, will depend on a whole load of environmental factors. The position of the lock. How big the cut in the lock is. How strong and which way the wind is blowing. How enclosed the space is. Etc etc!

But if it is unpleasant enough to induce vomiting in those exposed to it, then it’s very likely to drive them away from you bike, without stealing it.

Are there legal and moral questions about a lock that expels noxious gas into the face of thief? Unfortunately, yes. But they don’t really affect the security of the lock, so we’ll look at those later on. 

Security Summary

So just how well will the SkunkLock protect your bike? Visually, it looks the part. And that beefy form will scare off a surprising number of thieves.

Physically, it’s double bolted to resist leverage attacks and the shackle’s too wide for normal bolt cutters to get a grip on.

A hollow shackle will obviously never withstand a cutting attack as well as solid shackle. And this is where the SkunkLock has compromised physical security, in order to accommodate the extra layer of protection that only it offers: the gas attack.

The question is: does it make the right amount of compromise? Too much, and the lock isn't strong enough to take seriously. Too little and the lock will be unusable (due to excessive bulk and weight) or unviable (due to being too expensive).

In terms of security, I’d say they’ve got the balance about right. Even the regular, physical protection the SkunkLock provides should be pretty formidable. It shouldn't be defeated by casual thieves.

And then, the gas attack will provide that extra layer of protection against the more serious thieves (who are quite likely get through the more secure locks, as well, anyway).

Of course, a u-lock that’s full of noxious gas has to make compromises in areas other than security. And these compromises will effect the way you use the lock. So let’s look at those next…

Is the SkunkLock easy to carry?

As I’ve already mentioned, the SkunkLock is a beast. It’s big. And it’s heavy, However, it's much lighter than it looks, and much lighter than similarly sized locks, due to it’s hollow shackle...

OnGuard Brute Standard vs SkunkLock vs Kryptonite New York Standard

OnGuard Brute Standard vs SkunkLock vs Kryptonite New York Standard

It’s a standard sized sized u-lock, with internal dimensions of 4.25" x 9.0" (10.8 x 22.9 cm). Due to it’s bulk, it looks a lot like the OnGuard Brute Standard and the Kryptonite New York Standard.

But it’s actually significantly lighter, and at 3.92 lb (1.77 kg), its weight is closer to the Kryptonite Evolution 4 Standard or the Tex-lock, neither of which are considered particularly heavy locks.

SkunkLock vs Tex-lock

Like all big u-locks, there's a challenge as to the best way to carry it around on your bike. But unlike most other u-locks, it doesn’t come with a frame mount to help you out with this.

The problem is: designing a frame mount that can accommodate such a big lock, and that will fit on every bike, is really difficult. And even when you get it right, loads of people complain, (usually because they haven’t followed the installation instructions properly!).

So, I suspect the guys at SkunkLock have just decided to abdicate responsibility for this! Which is understandable from a start-up, but still frustrating, as you’re going to have to sort it out yourself...

You’re really left with three options: carry it around in a backpack or pannier, strap it to your luggage rack (if you have one), or buy a third party u-lock mount that will accommodate the SkunkLock.

SkunkLock in my saddle bag

The SkunkLock  tucked away in my saddle bag

I’d imagine that most cyclists will improvise with bags or panniers. And the fact that it’s not super heavy makes this much easier. On the other hand, because it’s really bulky, you might need a big(ger?) bag!

If you’d prefer to buy a dedicated frame mount, then make sure it accommodates the bulk of the SkunkLock. 

Fabric Horse u-lock holster
Kryptonite Transit H-bar handlebar u-lock holster
Huldit u-lock holster

Fabric Horse, Kryptonite and Huldit all make u-lock mounts that will fit the SkunkLock. And if you google “u-lock” holster you’ll find plenty more.

Is the SkunkLock easy to use?

The SkunkLock works much like any other standard size u-lock. True, it’s more bulky, so in a tight spot, you might struggle a little bit more to get it into position.

But the generous internal dimensions will actually give you loads of locking opportunities. You should be able to get it around your frame, one wheel and a bike rack very easily...

Locking the front wheel and frame

Locking the front wheel and frame

You should try to fill as much as the internal space with you bike and whatever you’re locking it to. This is good advise for any u-lock, to protect it from leverage attacks. But I would especially advise it for the SkunkLock.

SkunkLock around lamppost

The standard size shackle with give you loads of locking opportunities

With enough leverage (say from a length of scaffold pole), it’s not clear to me whether the hollow shackle would buckle or crack. Either way, the gas may be released and the lock would no longer be usable, so it’s best to try to prevent this!

For more options and the safest locking techniques, check out my article on how to lock your bike properly.

SkunkLock warning label in the way

I can't see the label lasting very long!

There is a laminated warning label attached to the lock, (for legal reasons, I presume). It could get in the way a bit when you’re trying to lock your bike up, and be slightly annoying.

But it’s apparently important that it remains attached to the lock. And if the original gets spoiled (which seem almost certain), you’re advised to replace it (SkunkLock can supply).

The shackle locks into the cross bar cleanly, and the keys turn easily. You’ll get 3 keys and a key code with which you can order more, should you lose them.

3 SkunkLock keys

You get 3 keys (and a replacement code) with the SkunkLock

There’s no cover for the keyhole, which has advantages and disadvantages. On the one hand, it leaves the locking mechanism exposed to water and street grime which could potentially corrode or jam it up.

However on the other hand, there’s less chance that water will get trapped in the mechanism (behind the keyhole cover) and freeze, which will also cause jamming issues. Plus there’s less things to break...

No protective keyhole cover

No protective keyhole cover!

I say this, having just spent an hour fighting a broken keyhole cover (with a screwdriver) that had made a different lock unusable.

So I wouldn’t worry about the keyhole cover. Whether a lock has one or not, the most important thing to do is to clean and lubricate it every few months. This will protect you against all sorts of problems in the future!

Is the SkunkLock a Single Use Lock?

One very important thing to consider is: what happens after the lock is attacked and releases it’s gas (hopefully repelling the thief)? Once the shackle is cut and the gas has escaped, it obviously won’t work again.

Well, apparently you can order replacement shackles from SkunkLock for around a third of the price of the lock, which seems fairly reasonable I suppose. But it is an extra cost that you should be aware of.

Is the SkunkLock Legal?

I think the most common question that most cyclists will have, when you tell them about a bike lock that spays thieves with a vomit inducing, noxious gas, (once they’ve finished celebrating, of course), is: “but is it legal?”.

And it’s a good question, with an (unfortunately) complicated answer. Because like so many other things in life, the legality or otherwise, will depend on where you are.

SkunkLock have gone to great lengths to ensure that the lock is legal in every country and state. The lock is plastered with warning messages and there are three different gas formulas to meet the legal requirements of different places.

Warning label on SkunkLock

The extensive warning label on the SkunkLock (do not remove)

For example in the EU and some US states, where pepper spray is not allowed, the gas doesn’t include capsicum (a key ingredient in pepper spray).

I think the thing to remember is that the SkunkLock is not weaponised, and the gas inside will not cause long term harm to anyone. It’s just meant to be so completely disgusting, that it will drive people away!

However, if you’re really worried about this you should consult the specific laws of your country or state.

Wrapping Up

The SkunkLock is something we’ve never seen before. But it’s something many cyclists have been calling for, for a long, long time. Finally: a way to fight back against the thieves that have been terrorizing our community!

The truth is, we won’t know how successfully it does this for a while. It needs to be tested against real thieves in the streets, sheds and garages, where we habitually keep our bikes. However, my experience with it, was very positive.

There’s a difficult balance to get right here. The lock needs to provide a sufficient level of conventional protection, to function reliably as a regular lock. And it needs to do that while maintaining a usable size and weight, and a realistic price. 

Now, there’s no doubt the SkunkLock is an expensive bike lock. It’s at the very top end of what you’d expect to pay. But it is unique. So we should expect to pay a bit more.

But what of that balance? For me, it seems like they haven’t compromised the conventional security too much. It looks and feels like a very secure lock. And while it’s a little bit more bulky than other standard size u-locks, it’s certainly not unusually heavy.

SkunkLock around back wheel and frame

Locking the back wheel and frame.

The lack of carrying options will be challenging for some (including me). I don’t usually carry a bag when I’m cycling and there’s nowhere else it will fit naturally on my bike. So I would have to buy a holster or take a bag with me specially.

Personally, I think the SkunkLock will work really well as a stay at home lock. The element of surprise and the effects of the cloud of noxious gas would be massively concentrated in the dark confines of a bike shed or garage. Hopefully leading to utter panic in the thief!

So I might be tempted to use it as home security and then bring it out (in a bag) if I was going to leave my bike in a particularly risky situation.

But other cyclists will have other bikes, other circumstances and other preferences!

What’s great, is than in the SkunkLock we have new options. Another layer of security. And a unique way to fight back.

If you're still not sure if it's right for you, check out my easy 3 step guide to choosing the best bike lock, or I've also selected three interesting, alternative locks below...

Alternatives to the SkunkLock

Of course, if the SkunkLock isn’t right for you, as always, there are other options. There are no other bike locks that are directly comparable with the SkunkLock in terms of function.

But there are couple that are similar in terms of form and one that has an extra level of protection too...

Kryptonite New York Standard

Kryptonite New York Standard

This is Kryptonite's toughest, standard sized bicycle lock [Amazon] (the M18 is considered more of a motorbike lock).

And with a whopping 16 mm shackle, it’s also probably the closest in form to the SkunkLock.

Despite being slightly less bulky than the SkunkLock, at 4.35 lb (1.97 kg), it’s over 10% heavier, (the SkunkLock weighs 3.92 lb (1.77 kg)). This is obviously due to the solid steel shackle.

But the Kryptonite will be easier to carry around because it comes with a frame mount. And it will also withstand cutting and twisting attacks for longer than the SkunkLock.

Indeed, the only way anyone is going to get through the New York Standard is with an angle grinder.

However, as we’ve already discussed at length, a thief can cut through this (and any other bike lock) with an angle grinder, and walk off with your bike, usually unchallenged.

Only the SkunkLock will bite back as it’s being compromised, hopefully driving the thief away, without your bike.

Kryptonite Evolution Series 4 Standard

Kryptonite Evolution Series 4 Standard

The Evolution Series 4 is the next standard size u-lock down (in terms of security) from the New York Standard.

It features a 14 mm solid steel shackle, which obviously makes it lighter and less bulky than it’s big brother.

And despite being much slimmer than the SkunkLock, at 3.75 lb (1.70 kg), it’s also just slightly lighter. So, whether you use the included frame mount or throw it in a bag, it will be easy to carry around too.

The solid steel shackle will offer more protection from conventional cutting and twisting attacks than the SkunkLock. 

But a thief with an angle grinder will make very quick and easy work of this lock. So it doesn’t have that extra layer of protection you get with the SkunkLock.

If thief with an angle grinder attacks the Evolution, there’s a very good chance they’re going to take your bike. Whereas if you’re using the SkunkLock, there’s a good chance they won’t. 

Abus 770 Smart X

Abus 770 Smart X

In terms of function, this Abus lock [Amazon] is probably the closest thing to the SkunkLock.

That’s because it’s got an alarm, which in effect, is another layer of security, just like the gas in the SkunkLock.

It’s also a smart lock which is a type of bike lock that I haven’t been impressed with so far

Whether we need smart locks or not, is a whole other conversation, which I’m not going to get into here. Spoiler: I don’t think we do!

But what’s important here is the alarm. As far as I can tell the 770A Smart X is the only Sold Secure Gold rated lock with an alarm. 

So we know it’s going to be pretty secure. The question is: what kind of deterrent is an alarm against a thief with an angle grinder?

The angle grinder part of this question is important, since it can also be used as a very dangerous weapon.

Bike thieves are certainly not above using an angle grinder to attack people. And passers by will at least suspect and fear that.

So if a thief is brazen enough to use an angle grinder in the street, he’s brazen enough to ignore an alarm. Because he also knows that passers by are very unlikely to intervene for fear of attack.

I’m not sure an alarm offers much extra protection!

SkunkLock Specs



My score:

Check price:

Shackle thickness:

24 mm


3.92 lb (1.77kg)

Size (internal):

4.25" x 9.0"
(10.8 x 22.9 cm)


Chemical Attack!

Other Security Ratings:


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Review Details
Review Date
Reviewed Item
SkunkLock Bike Lock
Author Rating
Product Name
USD 179.99
Product Availability
Available in Stock
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