The Best Chain Lock (and how to use it!)

Chain locks are generally less popular than u-locks. However, there are several great things about chains:

Firstly, their relative length and flexibility means you can secure your bike to a wider range of objects.

Secondly, for people that don't like those annoying u-lock frame mounts, the shorter, thinner chain locks can be carried relatively easily, wrapped around a seat post.

And finally, they are more resistant to some of the common methods of attack used on other bike locks. For example, they can't be bottled jacked or leveraged open. And they're more difficult to cut with power tools such as angle grinders.

However, these advantages come at a significant cost: they are very heavy. Chain locks are far, far heavier than u-locks that offer equivalent levels of security.

And because of this, we need to divide chain locks into two groups:

1. Lighter chain locks that you can use in the street and carry around everyday on your bike
2. Heavier chain locks that you leave permanently at home or work in a shed or garage, etc.

So before you buy a chain lock, you should decide what you're really after: portable or stationary security?

Below, I share 6 of the best chain locks according to my tests (4 for portable security and 2 for stationary security).

However, if you’re not sure which one is best suited to your circumstances, don't worry! Because after that there is a complete guide to choosing a chain lock which also includes a short quiz that will tell you what security level you require.

The 6 Best Bike Chain Locks

1. Seatylock Viking Silver: Best Mid-Security Portable Chain

The SeatyLock Viking Silver is the only chain lock with 7mm links that has a Sold Secure Silver rating. Which means it has a really good strength to weight ratio and enables you to use a longer length without the chain becoming ridiculously heavy.

I tested the 35.4" (90 cm) version, which, at 2.98 lbs (1.35 kg), weighs the same as 3.5 cans of Coke. Now, this doesn’t make it a super lightweight lock. There are certainly plenty of lighter u-locks.

But considering the 90 cm will give you tons more locking options than any u-lock, including the ability to secure 2 bikes at once, it’s pretty impressive.

However, be aware that this is not a lock for high risk circumstances. And 7mm chain links can be cropped relatively easily if the thief can get the lock in a position where they use the floor for leverage on the arms of the bolt cutters.

The remedy for this is to keep the chain as far from the floor as possible. And with a 7mm chain like this, I recommend that you wrap the chain tightly around the top tube, or around the seat stays and the back wheel in a manner that keeps it away from the ground.

The SeatyLock Viking also has one nice feature that I haven’t seen in other chain locks: a magnetized shackle. So if you're struggling to join the two ends together in a busy bike rack, the two ends will come together much easier, due to the magnetization.

I found this quite handy when I was testing it!

The SeatyLock Viking is available in two other lengths: 43.3" (110 cm) and 55.1" (140 cm), if you need an even longer chain. I would love to see a shorter 21.5" (55 cm) version, as well, for us city riders that like the flexibility of a chain but don’t need any more internal locking space than a standard size u-lock.

Are there any downsides to the SeatyLock Viking? Well, apart from the fact that this is very much a mid-security lock, and you need to be careful about where and how you use it, I would say the build quality could be better.

Compared to the robust moulded plastic finishing on the Kryptonite locks below, the thin rubber sheath that covers the end of the Viking seems very flimsy and can be easily moved out of the way to expose the chain links.

However, the Viking Silver range provides the lightest Sold Secure Silver rated chain locks you can buy. And if you’re looking for a chain that’s long enough to provide tons of locking opinions without weighing a ton, then they are definitely a good option.

See my full, hands-on SeatyLock Viking Silver 90 review for more details.

2. Kryptonite Kryptolok Series 2: Security & Practicality in Perfect Balance!

The Kryptonite Kryptolok Series 2 range of chain locks provides a significant step in security from the SeatyLock Viking.

This range uses 9mm chain links and has a Pedal Cycle Gold rating from Sold Secure. There are several lengths available, but I tested the shortest, 955 Mini.

The Kryptonite KryptoLok Series 2 955 Mini is just 21.5" (55 cm) long, which gives you about the same locking space as a standard size u-lock. I really like this length as it keeps the weight and bulk down, and makes it much easier to transport.

In fact, despite being much more secure than the SeatyLock Viking 90, the Kryptonite KryptoLok Series 2 955 Mini is only slightly heavier, at 1.77 kg (3.90 lb), which is about the same as 4.5 cans of Coke.

However, for many people, the attraction of a chain lock is the extra locking opportunities that longer chains provide. For those people, the Kryptonite KryptoLok Series 2 is available in three other lengths: 37.5" (95 cm), 47.3" (120 cm) and 60.0" (150 cm).

Be aware though, as these locks get longer, they get a lot heavier. The 60.0" (150 cm) version weighs 3.67 kg (8.10 lb), which is the same as 10 cans of Coke!

And if you would prefer a lock without keys, it's also available in two different lengths as a combination lock. In fact, these are the only combination chain locks that have Sold Secure ratings (other than some Bronze locks, which are rubbish)!

It’s still not a lock for very high risk circumstances, but if you keep the chain off the ground, it will be very difficult to defeat, and the build quality is also very good, meaning it should last for many years.

See my full, hands-on Kryptonite KryptoLok Series 2 955 Mini review for more details.

3. Best High Security Portable Chain: Kryptonite Evolution or Hiplok Gold?

I’m completely torn here, so I’m including them both! And the truth is, the best one for you will very much depend on your priorities.

The Kryptonite Evolution Series 4 1055 Mini is lighter, more compact and more secure. But much shorter.

The Hiplok Gold is easier to carry, and provides more locking opportunities. But is heavier and less secure.

With 10mm chain links, both the Kryptonite Evolution Series 4 and the Hiplok Gold are a step-up (in terms of security), from the Kryptonite KryptoLok Series 2, even though both locks have the same Pedal Cycle Gold rating from Sold Secure.

Despite the identical Sold Secure rating, it should be noted that while the Kryptonite Evolution has a 3 star rating from ART (which means it's secure enough to be used on motorbikes), the Hiplok Gold only has a 2 star rating, making it the less secure of the two locks.

However, chains with 10mm links start to get heavy and difficult to carry around on a bicycle. And this is where the Hiplok Gold has an advantage over the Kryptonite Evolution, in that it can be worn around your waist like a belt.

Note: you don’t lock it around your waist, as that would be dangerous if you got in an accident. Instead, there is a clip to fasten and unfasten it very quickly and easily. And it can be adjusted to fit waists from 28” (71 cm) to 44” (112 cm). So you should be able to get a comfortably snug fit.

The Hiplok Gold weighs 2.4 kg (5.3 lb), which is about the same as 6.5 cans of Coke, and that’s a fair bit of weight to be carrying around. However, in my tests, I hardly noticed it when I wore it around my waist.

While the Hiplok Gold is available in just one length: 33.5" (85 cm) (which should give you loads of locking options), the more secure Kryptonite Evolution Series 4 is available in 4 different lengths, from 21.5" (55 cm) to 63.0" (160 cm).

However, I would recommend sticking with the shortest, 21.5" (55 cm) version for portable security.

This is because the version that is closest to the Hiplok Gold, is 35.5" (90 cm) and weighs the same as 7.5 cans of Coke. That is a huge amount a weight (and bulk) to be carrying around, if you can't wear it around your waist (and you can’t)!

The shortest version is actually lighter than the Hiplok Gold, weighing 2 kg (4.4 lb), which is the same as 5.5 cans Of Coke. And it will give you the same internal locking space as a standard size u-lock, but more flexibility.

So for me, the choice is between the extra length and easy portability of the Hiplok Gold versus the higher security and lighter weight of the Kryptonite Evolution Series 4 1055. Personally, I would go with the Kryptonite, as I don’t need the extra length for my skinny city bike.

But if you ride a bulkier ebike or city bike, or you need to lock two bikes at once, then the Hiplok Gold would be the better choice.

See my full, hands-on Kryptonite Evolution Series 4 1055 Mini review and Hiplok Gold review for more details.

4. Hiplok DXXL: Best For Ebike and Stationary Security

The Hiplok DXXL provides a high security set up that you can use in several different ways. Primarily, it works as a stationary chain lock. By that, I mean that it’s a chain that you keep at home, to secure your bike in the shed or garage.

And that’s because at 6.11 kg (13.46 lb), its weight is equivalent to 16.5 cans of Coke! So it’s not really suitable to carry about on your bike every day.

The chain itself has 14mm links, which will be very difficult to crop, especially if you use a locking technique that keeps it as far from the ground as possible. The accompanying u-lock also has a 14mm shackle.

So it’s a very secure combination.

Indeed, both the chain and accompanying u-lock (which is the Hiplok DX) are Sold Secure Pedal Cycle Diamond, which is the highest rating available for bicycle locks.

The chain is only 39.0" (100 cm), but because it works as a noose, it makes the very most out of that length (as the chain doesn’t need to double up around your bike and whatever you’re locking it to).

Plus, the extra size of the u-lock (as opposed to a padlock), extends the locking length further.

When used with a ground or wall anchor like the Hiplok ANKR [Amazon], this becomes a really practical and secure way to protect your bike at home.

However, because the lock that accompanies the Hiplok DXXL is a fully fledged u-lock, you can also use it alone, as portable security for locking your bike in the street. It has a clip attached to the crossbar, which allows you to carry it around on your belt, and it’s one of my favourite mini u-locks.

So you get great stationary and portable security with the Hiplok DXXL!

The Hiplok DX is a mini u-lock, so it may not be suitable for all circumstances. But if you’ve got a chunky e-bike, for example you could even take the chain and the u-lock together into the street, as a powered bike is going to be less troubled by all that weight!

See my full, hands-on Hiplok DX review for more details on the u-lock. A full review of the Hiplok XL chain is coming soon.

5. Hiplok Mega Chain: The Ultimate Stationary Chain Lock for Bicycles and Motorbikes

For most people, the Hiplok DXXL will be the perfect stationary chain lock for home security. However, it’s not the most secure chain lock you can buy.

It can theoretically be cut by the largest bolt cutters, if a thief can get the chain in a position where they can use the floor for leverage, and they have the right technique and enough weight to bear down effectively on one arm of the tool.

So, for those looking for the ultimate security from a chain lock, the Hiplok Mega Chain is the answer (now that, unfortunately, Pragmasis and Almax have gone out of business). Because the Hiplok Mega Chain features 22mm links which are impossible to crop!

You won’t find another bike lock with thicker chain links than 22mm, by the way, they would just be completely impractical.

This lock is as big and tough as it gets.

The Hiplok Mega Chain weighs 12.3 kg (27 lb), which is the same as 33 cans of Coke! It’s 51"

(130 cm) long, and like the Hiplok DXXL, it uses a noose design to make the most of that length.

However, it does not come with a lock. And the links are so big, that they won’t fit through the openings of many ground anchors. So you will need to think carefully about what you’re going to pair it with.

It is compatible with the angle grinder resistant Hiplok D1000 and DX1000 (and therefore also the Litelok X1 and X3). So you could loop the chain around your bike and then fasten the end of the chain to one of these locks, which in turn locks to a ground anchor.

Or there are some ground anchors that will be big enough to accommodate this chain. I have added the maximum chain size each can take in my guide to the best ground anchors (and how to use them).

Hiplok even do bundles, where you can buy the chain with the DX1000 u-lock, or with the DX1000 u-lock and the A1000 ground anchor, with a 6.5% price reduction and 8% price reduction respectively!

So there are various ways to make the Hiplok Mega Chain work, and paired with the right lock and ground anchor, it will make one of the most secure setups for your bicycle that you could possibly get.

How to choose a chain lock for your bicycle

Let’s take a closer look at the most important things to consider when you’re choosing a chain lock, (including a quiz that will tell you exactly what security rating you need). Then we’ll review every chain lock with a Sold Secure rating, and links from 6mm up to 16mm.

The Chain

Not all chains are made from the same type of metal. For reliable security, the links of the chain should be made from a high quality, core hardened steel alloy, that's not too brittle.

The easiest way to guarantee this is to buy from a reputable brand such as Kryptonite, OnGuard, Abus or Hiplok etc.

Chain links usually have rounded edges. However, some security chains now have hexagonal or square links.

These are supposed to be more difficult for bolt cutters to grip, and spread the cropping pressure over a larger surface. So they're supposed to be harder to crop...

However, used bolt cutters will have nicks in the blades which can catch the edges of such links, actually making it easier to get a good grip. So in fact, these different shaped links offer no more protection than round links. Indeed, they may be easier to crop!

But obviously: the thicker the links, the tougher the chain lock...

Links with diameters less than 10 mm can be cut relatively easily with medium-sized bolt cutters, if the thief can get the chain in a good position.

Links with diameters of between 10 and 12 mm can sometimes be cut by medium size bolt cutters if the thief knows what they are doing and can get good leverage on the chain.

Whereas, links with diameters between 13 and 15 mm can only be cut by the very biggest 42" bolt cutters, which the vast majority of bike thieves won't have.

And at 16 mm and above, the links can’t be cut, by even the biggest hand operated bolt cutters.

But whatever its thickness, the chance of your chain being cropped can be significantly reduced by keeping the chain as far off the ground as possible when you lock your bike.

In order to crop a decent chain, the thief will need to use one arm of the bolt cutter against the ground as leverage. The further your lock is off the ground, the more difficult and less effective this will be.

The Lock

Any bike lock is only as strong as its weakest point. So there’s no point having a super thick, super strong chain if you’re securing it with a cheap, feeble padlock!

Chain locks usually come with their own locking mechanisms. Sometimes they're padlocks or mini u-locks. Sometimes they're permanently integrated into one end of the chain.

Either way, the locking mechanism should be reliable and should resist leverage attacks, picking, pulling and drilling.

If there’s a shackle, it should be as thick as (or thicker than) the chain links, or inaccessible to bolt cutters (shrouded).

Chain locks: Length vs Weight

One of the advantages of chain locks (over u-locks) is that their (generally) greater length gives you a wider range of objects to secure your bike to.

However, the longer the lock, the greater the overall weight. And chain locks get very heavy, very quickly. Even the lighter chains are often too heavy to carry comfortably in a bag on your back.

Yes, maybe you can attach them to your luggage rack, carry them in your basket or wrap them around your seat post. But, in order to minimize the extra weight, you should generally choose the shortest length that enables you to lock your bike where and how you want to.

Be careful though, some of the short ones are really short! Before you commit to buying a chain lock, measure out a length of rope and test that it's long enough to use wherever you normally lock your bike.

Having said all this, you will just have to accept that a chain lock is always going to be heavier than a u-lock that provides equivalent protection...

For example, the Kryptonite Kryptolock Series 2 u-lock weighs 2.85 lb (1.29 Kg). At the same security level, the lightest Kryptolock Series 2 chain lock is 3.90 lbs (1.77 Kg), nearly a whole pound and 30% heavier.

And at just 21.5" (55 cm) in length, it provides the same internal locking space as the u-lock. Yes, its flexibility is an advantage, but it’s hardly going to give you loads more options when looking for places to lock your bike.

A more practical 37.5" (95 cm) Krytolock Series 2 chain lock is available, but at 5.55 lbs (2.52 Kg) it weighs almost twice as much as the u-lock.

Chain locks are heavy! If that's a problem, get a u-lock or a folding lock instead.

Portable vs Stationary Chains

I imagine that you already know whether you want a mobile or stationary lock. It's a pretty clear distinction...

You'll use a mobile chain lock every day, carrying it around on your bike and securing it around your bike and the various street furniture in your neighborhood.

Whereas, a stationary chain lock will be left at home (or wherever you leave your bike overnight) and only used there to secure your bike (or more likely several bikes) over longer periods of time.

But what if you want both? Do you want a chain lock that you can carry around every day and use at home overnight? Well, there are locks that can do both. But they don't do either really well.

A two lock system (where you have one for daily use in the street and another that you keep at home for overnight protection) is usually the most secure and practical option.

But don't worry, we'll cover them all...

Choosing a portable chain lock

How secure should your chain lock be?

The best way to discover the security level of any bike lock, is to check the ratings from the independent testing house, Sold Secure.

If you want to know more about Sold Secure and why they provide the best measure of bike lock security, check out my guide to choosing the best bike lock.

All you need to know here is that Sold Secure test and measure bike locks according to their security level, rating each one Bronze (least secure), Silver, Gold or Diamond (most secure).

But how can you know which Sold Secure rating you need? Well, the best way to find out, is to answer the 3 quick questions in the quiz below…

Based on your answers to the three questions, the quiz should recommend either Silver, Gold or Diamond rated bike locks. Bronze locks aren't secure enough for any circumstances, so I don't recommend them at all!

There's quite a bit of variation in security within each rating. So some Silver rated locks are more secure than other Silver rated locks. And likewise for Gold and Diamond rated locks.

With chain locks, this will largely be determined by the link thickness. By choosing a thicker Silver (or Gold, or Diamond) chain link, you'll generally be choosing a more secure one.

How long should your chain lock be?

One reason to choose a chain lock (over a u-lock) is the extra options it gives you when you're looking for somewhere to lock your bike. More flexible and longer chain locks go places u-locks can't.

And the longer the chain lock, the more options you'll have. But longer chains are very heavy (as well as expensive).

So get the shortest length that you need to secure your bike. You can use a length of rope to work that out if necessary.

How should you secure your bike with a portable chain?

I recommend that you don't use a chain lock to secure your frame and your wheels in the same way you might normally use a u-lock:

Chains are much more vulnerable to bolt cutters than u-locks, and if they're too close to the ground (like in the photo above) a thief can use the ground for leverage and cut through the chain.

If you only use it to secure your frame (tightly wrapped around your top tube), you can keep the chain shorter (and lighter). And even more significantly: it will be further from the ground, so it will be much harder for a thief to crop it.

There are plenty of other ways to secure your wheels! And I've written lot's more about how to lock your bike properly.

However, you have a couple of options if you want to protect your frame and your rear wheel at the same time:

With a longer chain, you might be able to get it around your top tube and through your wheel too (as in the photo below).

Or you might be able to fasten it through your seat stays and your rear wheel, in a way that also keeps it a good distance from the ground (as in the photo below).

How will you carry your chain lock around?

Thinner, shorter chains locks can be carried wrapped around your seat post. Some brands sell chain bags that you strap to your frame. And there are even some chain locks that you can wear around your waist.

Make sure you've thought about this before you buy one. Is there room on your seat post? If not, is there room in your bag or your panniers? There are other places to put your lock when you're riding, but chains can be more challenging than other bike locks.

6 mm chain locks

I wouldn't usually recommend 6 mm chain locks under any circumstances. They can be cropped or cut far too easily.

And I've never seen a 6 mm chain lock with more than a Sold Secure Bronze rating, which is just not good enough to protect our bikes!

However, there is one very unusual exception. The tex-lock is a 6 mm chain, encased in a thick textile cover, which makes it look and feel more like a length of rope than a chain lock!

The textile cover provides an additional layer of protection for the chain and if you pair it with their Sold Secure Gold rated X-lock, you get a very versatile bike lock...

In high risk circumstances, you can use the X-lock to secure your frame and the chain to protect your wheels. In low risk circumstances, you can use the chain to secure the frame, (and the X-lock to protect one wheel), with the extra length giving you loads of locking options!

But be careful...

You need to understand the different security levels of the different parts of this chain lock (and how to use them properly), to get the best out of it. The textile covered chain is not rated by Sold Secure and is only suitable for short stops in low risk circumstances.

And the X-lock is very, very narrow, so will only fit around Sheffield bike stand sized immovable objects. 

Check out my full tex-lock review here and read how the X-lock made my best lightweight bike lock list before you buy.

Update: Get 10% off any purchase of Tex-lock products by using the code "bestbikelock10".

7 mm chain locks

7 mm chain locks are at the lowest end of what's an acceptable level of protection for your bike. And the only 7mm chain that currently has a Sold Secure Silver rating is the Seatylock Viking Silver.

Click on the links in the table to check the prices at Amazon (or other retailers).

* In all the tables on this page, I also give the weight in cans of Coke to help you understand just how heavy the chain locks are. On mobile, you just need to click on the small plus sign above the image to see these (and the security ratings).

If your circumstances are low risk, then you might be able to get away with a 7 mm chain lock. But don't leave your bike unattended for long periods, and be careful with your locking technique.

As I mention above, I strongly advise that you don't use a 7mm chain lock in the same way you’d normally use a u-lock. This will leave it too near the ground, where thieves can leverage a pair of bolt croppers to cut it relatively easily.

Instead, wrap the chain lock tightly around your top tube and whatever you're locking the bike to. This will keep the lock away from the ground and make it impossible for a thief to move it closer.

I think 7 mm chain locks could still be cropped without using the ground, if the thief has big enough bolt cutters and enough strength. But most bike thieves won't!

There are plenty of alternative ways to protect your wheels, that won't put the whole bike at risk.

8 mm chain locks

They are only 1 mm thicker than the 7 mm chains and although this makes them a fair bit more secure, they still only get a Silver rating from Sold Secure…

Click on the links in the table to check the prices at Amazon (or other retailers).

My favorite is the Hiplok Original [Amazon] chain lock, It's got a good weight to length ratio. Plus, it comes with an integrated Velcro strap, which allows it to be worn around your waist like a belt!

This is a really convenient way to carry your chain lock around. It's quick and easy to get it on. And the way the weight is distributed means you'll barely notice it's there.

I’m less keen on the Hiplok Homie Silver, though. This lock is specifically designed for stationary, home use, and to be honest, I think we need better protection at home than any 8 mm chain lock can provide.

It's also worth noting that the weight of these locks is becoming significant. The lightest chain locks in the table above, are the same weight as 4.5 cans of Coke, and already heavier than many Sold Secure Gold rated standard size u-locks!

Again, with 8 mm chains, I recommend that you secure your bike by wrapping the lock tightly around your top tube or the seat stays, so it can't be maneuvered close to the ground, where it's vulnerable to bolt cropper attacks.

9 mm chain locks

At 9 mm, chain locks start to get significantly more secure, and many have Sold Secure Gold ratings.

However, be aware that the Gold rating is usually accompanied by a 2/5 rating from ART (another independent security testing organization), which puts these locks at the lower end of the Gold scale.

Click on the links in the table to check the prices at Amazon (or other retailers).

As discussed above, I like the Kryptonite Kryptolok Series 2 range. But the Abus CityChains [Amazon] are another good option.

They have better weight to length ratios (they're lighter than the Kryptonite chains). But the Kryptonite chain locks will usually be cheaper, and are also eligible for an optional anti-theft protection, for bikes worth up to $1,500 / £800.

Don't forget, though: 9 mm locks are heavy! Even the short Series 2 955, which has the same internal locking space as a standard size u-lock, weighs more than 4 cans of Coke. And the longer chains are much heavier than that.

Both Kryptonite and Abus sell carry cases and bags that allow you to strap them to your frame. Since these cases keep the chains close to the frame, they should be more successful than most u-lock frame brackets (where the offset center of gravity makes u-locks unstable).

But check out the weights before you buy. Because people can be very surprised when they receive their chain lock and feel the weight in their hands for the first time!

10 mm chain locks

At 10 mm, we're starting to reach the limits of portable security. For sure: the shorter chains can be used as daily bike locks on the move. But they're very heavy…

Click on the links in the table to check the prices at Amazon (or other retailers).

I think a lot of the locks on the list are more suited for stationary use, as they feature separate padlocks. In fact, the Hiplok Homie [Amazon] chain lock is specifically designed with home use in mind. It's a nice 60" (150 cm) in length, which allows you to secure several bikes at once.

And it comes with an integrated hook, so you can hang it on the wall when you're not using it!

For mobile security, where you might be locking and unlocking several times a day in busy bike racks, an integrated lock is more convenient. It's simply quicker and easier to secure your bike when the lock is integrated into the chain rather than separate.

However, if you favor portability, definitely go for the Hiplok Gold [Amazon], as it's by far the easiest chain lock to carry around. It does feature a separate padlock, so it will take a little longer to lock your bike, but the ease of transport, makes it worth it.

If you favor locking speed, then go for either the Kryptonite Evolution Series 4 1055 Mini [Amazon], the Abus Granit CityChain X-Plus 1060/85 [Amazon] or the Seatylock Viking Gold, as their integrated locks speed things up a bit.

The Seatylock Viking [Amazon] range even has a magnetic mechanism, which makes it much easier to connect the two ends of the lock in a busy bike rack!

If you want to know more, you can read my reviews of the Hiplok Gold chain lock and Kryptonite Evolution chain lock.

A chain lock for the street and the home?

These locks can arguably be used for stationary as well as mobile security. But be aware: in order to be portable, they need to be short. And if they're short, they're difficult to use at home.

So if that's what you're after, proceed with caution...

12 mm chain locks

At 12 mm, we are definitely at the limit of what can be used daily as mobile security. These locks are big and heavy...

Click on the links in the table to check the prices at Amazon (or other retailers).

However, they also provide a very high level of security. Take a look at the security ratings. Not only are they nearly all Sold Secure Gold or Diamond, all those rated by ART receive 3/5 or 4/5.

This makes them suitable for motorbikes and expensive ebikes, and more secure than all but the most extreme u-locks.

However, it does not mean they can't be cropped! A thief using a pair of 42" bolt croppers and the ground for leverage may well be able to cut all of these chain locks.

So again, even with these thick chains: keep them as far from the ground as possible.

But with a 12 mm chain you don't have to be quite so careful. There aren't too many thieves that would have the right croppers, the necessary skill and enough body weight to cut a 12 mm chain lock.

The Kryptonite New York Noose [Amazon] is definitely the best 12 mm chain lock. There's a large, circular link at one end of the chain. And by threading the other end of the chain through the circular link, you create a noose which can be tightened around whatever you're locking your bike to.

Why is this so great? Well, it substantially increases the practical length of the chain lock, which means you don’t need to buy such a long one, saving you both bulk and weight!

It also makes it more useful at home as a stationary lock, where usually you'll need a bit more length to work with.

I explain all this in more detail in my review of the Kryptonite New York Noose 1275 chain lock.

Since even the shortest 12 mm locks are right on the limit of what is portable, the longer locks are definitely best used for stationary security at home (or wherever you leave your bike overnight).

The Kryptonite New York [Amazon] chain lock is a good choice here. It comes in three different lengths, with a separate disc lock that has a 14 mm, double locking shackle. And the optional anti-theft protection covers bikes worth up to $3,500 / £1300.

To be clear: any of these 12 mm locks will offer great high security protection at home and on the move if used correctly. But if you're going to use them as mobile protection, please check you're OK with the weight first!

Choosing a stationary chain lock

If we're choosing a chain lock to leave at home (or wherever we leave our bikes overnight), we don't need to worry about the "risk level" questions...

Both bike statistics in the UK and bike statistics in the US suggest that over 50% of stolen bikes are taken from the owner's home. So your bike is actually more at risk at home than it is when it's locked on the street.

With that in mind, my advice is: get the most secure bike lock you can afford. And this means the thickest chain lock you can afford.

And the great thing is: we don't have to worry about how we're going to carry it around!

14 mm chain locks

When we get to 14 mm chains, we’re no longer talking about mobile security. These aren’t locks that you take with you to the shops.

Their bulk and weight mean that generally you leave them wherever you secure your bike overnight.

Click on the links in the table to check the prices at Amazon (or other retailers).

A 14 mm chain lock could be taken out with you occasionally, if you're visiting a particularly high risk area, or you'll be leaving your bike unattended for a long period. But the lightest 14 mm chain lock in the list above weighs the same as 13 cans of Coke!

These locks are very secure indeed. The Kryptonite New York Fahgettaboudit is rated both Sold Secure Bicycle Diamond and Motorcycle Gold.

That's not to say they can't be cropped, though. They can. 14 mm chains can conceivably be cut by the very biggest bolt cutters. But it takes an experienced thief, of considerable weight, who is also able to get the chain in the right position.

So again I'll say: keep your chain as far from the floor as possible. In a bike shed or garage, this might mean installing a wall anchor rather than a floor anchor to use with the chain lock.

To be honest, there's not a huge amount of choice at this level.

With Kryptonite's New York Fahgettaboudit chains, you get a 15 mm double locking shackle, the maximum 10/10 in house security rating (as well as the Sold Secure ratings). Plus optional anti-theft protection which covers bikes worth up to $3,750 / £2000.

With OnGuard's Beast chains, you get a 14 mm, quadruple locking shackle, a maximum 99/100 in house security rating and optional (but useless) anti-theft protection for bikes worth up to $5001.

OnGuard's locks aren't rated by Sold Secure, simply because they haven't been submitted for testing. Have no doubt: they are very secure!

Usually, an OnGuard chain lock will be significantly cheaper than those from Kryptonite. However, they're not as pick resistant, and the after sales care and anti-theft protection isn't as reliable.

As discussed above, though, the Hiplok DXXL Noose is my favorite, as the u-lock can be used for portable security.

15 mm chain locks

There aren’t many widely available, 15 mm chain locks. For example, the very impressive Kryptonite New York Legend is difficult to find these days, but it’s a great lock…

Click on the links in the table to check the prices at Amazon (or other retailers).

It's still theoretically possible for the right thief, in the right position, with the biggest bolt cutters, to crop this chain lock. But I've never heard of it actually happening!

That ART give it a maximum 5/5 stars says it all, really. This is one of the strongest bicycle locks you can buy.

The lock features a 16 mm double locking, shrouded shackle. And optional anti-theft protection covers bikes worth up to $4500 / £2500.

This is a fantastically secure chain lock for bicycles. In fact, from the three big lock brands, it is probably the most secure bike chain available. Read my full review of the New York Legend.

The Artago Stone 68T100 is also an impressive looking lock and more widely available, but I haven’t tested this one.

16 mm chain locks

Finally, at 16 mm, these chains can no longer be cropped by any manual bolt cutters. They can only be defeated by power tools.

And they're incredibly heavy. Not only are they completely non-transportable, you’ll also need to be careful that they don’t damage your bike, just through their weight!

The British brands Pragmasis and Almax used to produce the best 16 mm chains. But unfortunately, both companies have recently gone out of business. So there’s not of choice left here.

The Oxford Nemesis is probably a safe choice (although I haven’t tested it). Otherwise, you could take a step-up to the 22mm Hiplok Mega Chain that I recommend at the top of the page.

This is the most secure chain available at the moment and is compatible with their angle grinder resistant u-locks (the D1000 and DX1000) and several of their ground and wall anchors. As discussed above, they even do discounts if you buy them together!

Best Chain Lock Summary

There are two types of bicycle chain lock:

1. those light enough to carry around on your bike daily
2. those so heavy they're best used as stationary security

Portable Chain Locks

Portable chains have links that are less than 13 mm thick. And even 12 mm will be too much for most people. They're far heavier than u-locks. But they do have several advantages...

1. Because they're relatively long and flexible, you can secure your bike to a wider range of objects.
2. Because you can wrap them around your seat post or top bar, they can sometimes be easier to transport.
3. They can't be defeated by leverage attacks and are more difficult to cut with an angle grinder (since the links move about when you try to cut them).

However, one big disadvantage they have in terms of security is the fact that the < 12 mm links that make up a portable chain lock can be cropped by manual bolt cutters fairly easily (if they're close to the floor).

And this is why, if you choose a chain lock for portable security, I recommend you secure your bike by wrapping the chain tightly around your top tube or around the top of your seat stays. 

This will keep it away from the ground and make it very difficult (if not impossible) for a thief to crop a decent portable chain lock.

You might have to come up with a different way to protect your wheels, but there's loads of options and at least your bike will be safe!

Please check the weights carefully before you buy, though. Even the shortest portable chain lock will be heavy. If weight is a big issue, then you're probably best off with a u-lock.

The Hiploks have good security to weight ratios. And you've also got the useful option of carrying them around your waist.

For protection in low risk circumstances, the Seatylock Viking Silver chain lock is a good choice. For medium risk, the Kryptonite Kryptoloks or the (even more secure) Abus CityChains are more appropriate.

But if your circumstances are high risk, then the Kryptonite Evolution Series 4 1055 Mini, Hiplok Gold, or Kryptonite New York Noose would be my choice.

Stationary Chain Locks

Stationary chains usually have links that are thicker than 13 mm. And there are several reasons why for immobile, overnight security these are the best option...

1. Security: they can’t be defeated by bottle jacks or leverage attacks, are more difficult to attack with power tools (like angle grinders), and if the links are thicker than 15 mm, they can’t be cropped by any manual bolt cutters.
2. Practicality. When you're securing a bike at home, in a garage or bike shed, then the best way to do that is with a ground (or wall) anchor. And chain locks work far better with anchors than any other type of lock. Plus, you can get a chain lock that is long enough to go around several bikes at once!

Of course, any bike lock is only as secure as its weakest link. And this is particularly relevant when we talk about stationary chain locks, which may be used in a shed or garage or even with other bike storage ideas.

Make sure that whatever you secure your bike to is as secure as the chain lock. If you don’t have anything appropriate, then you should invest in a good ground anchor. And make sure you know how to lock your bike properly.

I hope this page has been useful and that it’s helped you find the best chain lock for your bike. Once you've bought a chain lock, don't forget to clean and lubricate it every few months to stop it jamming.

And if you have any feedback or questions, please let me know below…

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.