Chain locks are made up of a series of hardened steel links (usually inside a protective nylon sleeve) and a lock. The lock can be integrated into the chain, or it can be a separate padlock.
There are several great things about chain locks:
First of all, their relative length and flexibility means you can secure your bike to a wide range of objects.
Secondly, they can be carried relatively easily wrapped around your seat post, so you don't have to deal with any of those annoying u-lock frame mounts!
Chains: easy to carry around your 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.
However, these advantages come at a significant cost: they are very heavy. Chain locks are far, far heavier than u-locks offering equivalent levels of security.
Because of this, we need to divide chain locks into two groups:
- those that are light enough to carry around everyday on your bicycle
- those that are so heavy you need to leave them permanently in one place.
So before you buy a chain lock, you should decide what you're really after: portable or stationary security? And once that's established we can find the best chain lock for you.
Don't worry, we'll cover it all here...
Let's start with the qualities that are common to both groups and the things we should be looking out for when buying a chain lock.
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 Pragmasis.
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...
Hexagonal chain links: are not more secure...
... than round chain links
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...
Chain Link Thickness | Can be cut by bolt cutters? |
|---|---|
< 13 mm | Yes (medium size) |
13 - 15 mm | Yes (only biggest 36 and 42") |
16 mm and above | No |
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 most bike thieves will not have.
And at 16 mm and above the links can’t be cut by even the biggest hand operated bolt cutters.
16 mm chain links are really big and heavy!
But whatever it's 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 it’s 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 one end of the chain.
Either way, the locking mechanism should be reliable and should resist leverage attacks, picking, pulling and drilling.
Shackle should be at least as thick as chain or...
... shrouded so it can't be cropped
If there’s a shackle, it should be as thick as (or thicker than) the chain links or inaccessible to bolt cutters (shrouded).
Chain Lock 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. It's true: they can easily be attached to your luggage rack, carried in your basket or wrapped around your seat post.
However, 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...
Kryptonite Kryptolok Chain Lock | |
|---|---|
 | |
Length: | 21.5" (55 cm) |
Weight: | 3.90 lb (1.77 kg) |
Security rating: | 6/10 |
Kryptonite Kryptolok U-Lock | |
|---|---|
 | |
Internal Space: | 21.5" (55 cm) |
Weight: | 2.85 lb (1.29 kg) |
Security rating: | 6/10 |
For example, the Kryptonite Kryptolock Series 2 u-lock weighs 2.85 lb (1.29 Kg). 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’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.
How to choose the best chain lock for you!
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 we'll cover them all...
Choosing a portable chain lock
How secure should your chain lock be?
The best way to know 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…
(The quiz above is new! If you have any problems with it, please send me a message to let me know. Thanks.)
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.
But how should you secure your bike with a portable chain lock? I'd recommend that you don't use a chain lock to secure your frame and your wheels.
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.
How will you carry your chain lock around?
Chains locks are best carried wrapped around your seat post (although some brands sell bags that you strap to your frame).
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 are 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!
Combined with the X-lock the Tex-lock is very versatile!
The textile layer provides enough additional protection to have won the chain a Silver rating from Sold Secure. And if you pair it with their 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 lower 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!
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 31.5" (80 cm) | 3.13 lb (1.42 kg) |  | |
 | 47.2" (120 cm) | 3.73 lb (1.69 kg) | | |
 | 63.0" (160 cm) | 4.28 lb (1.94 kg) | |
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, so check out my full tex-lock review here! And read how it even made my best lightweight bike lock list!
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 very lowest end of what's acceptable protection for your bike. But the Kryptonite Keeper is probably the best of the bunch, with a Silver rating from Sold Secure...
Click on the links in the table to check the prices at Amazon (or other retailers).
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 21.5" | 2.06 lb (0.93 kg) |  | |
| 33.5" (85 cm) | 3.50 lb (1.59 kg) | | |
| 47.3" (120 cm) | 3.75 lb (1.70 kg) | |
If your circumstances are low risk, then you might be able to get away with a 7 mm chain lock. Just don't leave your bike unattended for long periods and be careful with you locking technique..
I strongly advise that you don't use a 7mm chain lock to secure your wheels. 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 your 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 this chain lock could still be cropped without using the ground if the thief has big enough bolt cutters and enough strength. But many bike thieves won't!
What about your wheels? Well, if you're using a 7 mm chain lock, I'd imagine that neither your bike nor your wheels are particularly expensive or desirable.
So you may be able to get away with simply swapping out the quick release levers for standard bolts. Otherwise, there are plenty of alternative ways to protect your wheels that won't put the whole bike at risk.
8 mm chain locks
They're 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).
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 23.6 " (60 cm) | 2.87 lb (1.3 kg) | | |
 | 33.5" | 3.86 lb (1.75 kg) | | |
 | 33.5" | 4.08 lb | | |
 | 33.5" | 4.26 lb | | |
 | 35.43 " (90 cm) | 3.75 lb (1.7 kg) | | |
 | 35.4 " | 3.73 lb | | |
| 43" | 5.5 lb | | |
| 43" | 5.62 lb | | |
| 55" | 6.17 lb | | |
| Abus Steel-O-Chain 9808/170 | 67" | 7.08 lb | |
My favorite is the Hiplok Original [Amazon] chain lock It's got the best weight to length ratio. This means it's much lighter than similarly sized, (or even smaller) chains.
Plus it comes with an integrated Velcro strap which allows it to be worn around your waist like a belt!
Hiploks can be worn 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.
But it's worth noting that the weight of these locks is becoming significant. The lightest 85 cm Abus chain lock in the table above, is 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, so it can't be maneuvered close to the floor where it's susceptible to bolt cropper attacks.
9 mm chain locks
At 9 mm, the chain locks start to get significantly more secure. We see several with Sold Secure Gold ratings.
However, be aware that the Gold rating is usually accompanied by a 2/5 rating from ART 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).
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 21.5" | 3.90 lb (1.77 kg) |  | |
 | 33.5" | 4.4 lb |  | |
| 37.5" | 5.55 lb | | |
| 43" | 5.29 lb | | |
 | 35.5" (90 cm) | 5.85 lb (2.65 kg) | | |
| 55" | 6.04 lb | | |
| Cell | Cell | | |
| 59" | 8.10 lb | | |
| Abus CityChain | 67" | 7.45 lb | |
There's not a huge amount of difference between the Kryptonite Kryptolok Series 2 [Amazon] chain lock and the Abus City Chain 1010 [Amazon] to be honest.
Both feature integrated locks (as most chains < 12 mm do). They're both rated Sold Secure Gold. But both offer good mid level security rather than high security (see the 2/5 from ART).
However the Abus chains have better weight to length ratios (they're lighter than the Kryptonite chains). While the Kryptonite chain locks will usually be cheaper!
Kryptonite Kryptolok: a sensible mid-security choice
The Kryptonite chain locks are also eligible for an optional anti-theft protection, for bikes worth up to $1,500 / £800.
They both come in a variety of lengths. But I recommend you go for the shorter chains and wrap them tightly around your top tube rather than using longer chains to secure your wheels as well.
As already mentioned this keeps them away from the floor where they're more at risk of being cut with bolt croppers. And have no doubt: a 9 mm chain lock is definitely croppable!
Now don't forget: 9 mm locks are heavy! You can of course wrap them round your seat post. But 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 centre of gravity makes them 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!
Read my full, hands-on review of the Kryptonite Kryptolok Series 2 955 Mini chain lock.
10 mm chain locks
At 10 mm, we're starting to reach the limit 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).
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 21.5" | 4.40 lb |  | |
 | Abus Granit CityChain | 33.5" | 4.63 lb | |
 | 33.5" | 4.85 lb | | |
 | 35.4" | 5.3 lb | | |
| 36" | 6.10 lb | | |
| 43" | 5.84 lb | | |
 | 43" | 5.95 lb |  | |
 | 43.3" | 6.2 lb | | |
 | 43" | 6.39 lb | | |
| 55" | 7.19 lb |  | |
 | 55" | 7.50 lb | | |
| 63" | 9.70 lb | | |
| 67" | 8.27 lb | | |
| 72" | 8.38 lb | | |
| 72" | 9.28 lb | |
The shortest (and lightest) 10 mm chain lock in the table above (the Kryptonite 1055 Mini) is almost as heavy as the 18 mm Kryptonite New York Fahgettaboudit Mini (one of the heaviest u-locks).
And that's a lot of weight to be carrying around every day.
However these locks are also very secure. With two exceptions, they're all Sold Secure Gold. And 3/5 from ART put them at the higher end of that Gold rating.
They're still croppable though! If a thief has a large set of bolt croppers and can use the ground for leverage, they can definitely cut this chain lock.
So I would still recommend you keep the 10 mm chains tightly wrapped around your top tube when locking your bike. And use one of the alternative ways to secure your wheels.
Again, the Hiplok [Amazon] is a good choice here. It an be worn around the waist like a belt so it's easier to carry than the other options.
Hiplok Gold: 12 mm but still easily portable!
Be aware though, it's still heavy: the weight is equivalent to carrying 6 cans of coke around your waist! Read my full, hands-on review of the Hiplok Gold bike chain lock.
What about the other 10 mm chains?
The Kryptonite chains are eligible for optional anti-theft protection for bikes worth up to $2,250 / £1000. And Kryptonite's Key Safe program will replace lost or broken keys.
Evolution Series 4: The LockPickingLaywer's lock of choice!
There's no anti theft protection with Abus locks but they do come with a code card for additional or replacement keys.
Granit CityChain X-Plus: good weight to security ratio
And for me, the choice would be between the Hiplok, Kryptonite or Abus chains, because the OnGuard 10 mm chains are strange prospect...
The 8020 and 8021 Mastiff are two different lengths of the same chain (featuring an integrated lock). And despite the beefy 10 mm chains, both locks are only rated Sold Secure Bronze!
This makes them low security. I wouldn't recommend any bike locks that have a Bronze rating, let alone heavy 10 mm chain locks that cost a fair bit of money and weigh a ton! I write about this more in my review of the OnGuard Mastiff 8020.
A 10 mm chain with a Sold Secure Bronze rating?!
But the bottom line is: avoid the OnGuard Mastiff 8020 and 8021!
By contrast, there's nothing wrong with the security levels of the OnGuard 8019 or 8019L Mastiff. They're both Sold Secure Gold.
But they feature separate padlocks. And I think 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.
So, if you favour portability, definitely go for the Hiplok Gold [Amazon], as it's by far the easiest chain lock to carry around. Because of the separate padlock, it will take a little longer to lock your bike though.
So if you favour locking speed, then go for either the Kryptonite Evolution Series 4 1055 Mini [Amazon] or the Abus Granit CityChain X-Plus 1060/85 [Amazon] as their integrated locks speed things up a bit.
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 I'd say that 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 your 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).
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 30" | 6.95 lb |  | |
 | 39" | 8.65 lb | | |
 | Abus Granit Extreme Plus 59/110 | 43" | 8.82 lb |  |
 | 43" | 9.2 lb | Cell | |
| 51" | 10.55 lb | | |
| 55" | 10.36 lb | | |
 | 60" | 9.48 lb | | |
| 67" | 12.57 lb | | |
| 67" | 13.15 lb | | |
| 72" | 13.7 lbs | Cell |
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, all those rated by ART receive 4/5.
This makes them more secure than all but the most extreme u-locks.
However it does not mean they cant 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. Personally I'd still recommend you keep them wrapped around the top tube.
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 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.
The noose system gives you more length
Why is this so great? Well, it almost doubles 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 best used for stationary security at home (or wherever you leave your bike overnight).
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.
The Hiplok Homie: has a hook to hang it on the wall when not in use
And it comes with an integrated hook so you can hang it on the wall when you're not using it!
What about the other options in this list?
The Abus Granit Extreme Plus chain lock is actually classed as a motorcycle lock by Abus, who give it their maximum 20/20 in house security rating. It features an integrated lock for ease of use.
The Kryptonite New York chain lock comes with a separate disc lock that has a 14 mm, double locking shackle. And optional anti-theft protection covers bikes worth up to $3,500 / £1300.
The Beast 8017 (and 8018) from OnGuard also uses a separate padlock with a 11 mm, double locking shackle. And the shackle is shrouded so it's impossible to crop when it's being used with the chain (due to it being inaccessible).
These OnGuard locks haven't been rated by Sold Secure or ART. But don't worry about that (unless your insurance policy stipulates a Gold rated lock)...
It's not that these two locks aren't secure. It's that they haven't been submitted for rating. Have no doubt: these OnGuard chains are very secure locks!
Any of these 12 mm locks will offer great high security protection at home or 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 are not locks that you take with you to the shops.
Their bulk and weight mean that generally you leave them wherever you lock your bike overnight.
Click on the links in the table to check the prices at Amazon (or other retailers).
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 39" | 10.80 lb |  | |
 | 43" | 14.8 lb | Cell | |
| 60" | 15.25 lb | | |
| 72" | 22 lb | Cell |
However 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.
These locks are very secure indeed. The Kryptonite New York Fahgettaboudit not only has Gold rating from Sold Secure. It also has a Motorcycle Gold which is an even more demanding rating.
That's not 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 a experienced thief, of considerable weight who is also able to get the chain in the right position.
So again I'll say: keep you 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.
There's not a lot to choose between the Kryptonite and OnGuard chains here. They're both great locks!
OnGuard Beast: very secure and usually cheap!
With Kryptonite's New York Fahgettaboudit chains you get a 15 mm double locking shackle, the maximum 10/10 in house security rating, and both Motorcycle and Bicycle Gold ratings from Sold Secure. Plus optional anti-theft protection which covers bikes worth up to $3,750 / £2000.
With OnGuards Beast chains you get a 14 mm, quadruple locking shackle, a maximum 99/100 in house security rating and optional anti-theft protection for bikes worth up to $5001.
Again, OnGuards locks aren't rated by Sold Secure simply because they haven't been submitted.
Usually an OnGuard chain lock will be significantly cheaper than those from Kryptonite [Amazon]. However they're not as pick resistant and the after sales care and anti-theft protection isn't as reliable.
15 mm chain locks
There's only one widely available 15 mm chain lock. And that's the very impressive Kryptonite New York Legend...
Click on the links in the table to check the prices at Amazon (or other retailers).
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 36" | 9.50 lb | | |
| Kryptonite New York Legend Chain 1515 | 60" | 15.95 lb | |
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.
New York Legend: most secure widely available lock
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.
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.
Header | Model | Length | Weight | Security Ratings |
|---|---|---|---|---|
 | 28" | 9.15 lb | | |
 | 39" | 12.13 lb | | |
| 60" | 17.09 lb | | |
| 60" | 17.09 lb | | |
| 79" | 22.05 lb | | |
| 79" | 22.05 lb | | |
| 98" | 27 lb | | |
| 98" | 27 lb | |
And they're incredibly heavy. Not only are they completely non-transportable, you’ll also need to be careful they don’t damage your bike just through their weight!
The Protector range from Pragmasis is perhaps the ultimate bicycle chain lock. The 16 mm links are formed from hardened boron steel and are impossible to bolt crop.
It comes with a Squire SS65CS Stronghold Lock which has a shrouded shackle which is also impossible to bolt crop!
16 mm Pragmasis Protector with Squire Stronghold
The only way a thief is going to defeat this lock is with power tools and it will take a long time and make a lot of noise!
Very similar to the Protector range, the Almax Immobiliser Series III is slightly cheaper, (although I’m not sure it’s available in the US). It’s also made from 16 mm hardened boron steel links. And it comes with the same Squire SS65CS Stronghold Lock.
Personally, I'd go for a Pragmasis chain lock because I like their environmental policies. But I appreciate that not everyone can afford to be so picky!
Best Chain Lock Summary
There are two types of bicycle chain lock:
- those light enough to carry around on your bike daily
- 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 many people. They're far heavier than u-locks. But they do have several advantages...
Firstly, because they're relatively long and flexible, you can secure your bike to a wider range of objects.
Secondly, because you can wrap them around your seat post or top bar, they can be easier to transport.
And thirdly 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.
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'll have to come with a different way to protect your wheels, but there's load 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 big issue then you're probably best off with a u-lock.
The Hiploks have great security to weight ratios. And you've also got the useful option of carrying them around your waist.
For protection in really low risk circumstances, the Kryptonite Keeper chain lock is a good choice. For medium risk, the Kryptonite Kryptoloks or the (even more secure) Abus CityChains are more appropriate.
But if you're circumstances are high risk, then the Kryptonite New York Noose or Gold Hiplok chain lock 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...
First of all: 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.
Indeed 15 and 16 mm chains are the most secure way to lock your bike.
Secondly: practicality. When you're securing a bike at home, in a garage or bike shed, then the best way to that is with a ground (or wall) anchor. And chain locks work far better with anchors than any other type of lock.
And since at home, you might be securing more than one bike at a time, you can get a chain lock that is long enough to go around all of them!
Of course, any bike lock is only as secure as it's 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 you 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.
Any views on EBC’s Revolution Secure chain lock? Seems remarkable value for money (esp. as often discounted in sales), and I’ve used it a number of times in South Manchester without any sign anyone’s even tried to attack it. But maybe I’ve just been lucky?!
Wow that is cheap Mark! And with 10 mm thick links and a 15 mm shackle, it’s an intimidating looking chain. The thing is, not all chains are created equal. Cheap chains won’t be made from the highest quality steel alloy, won’t be properly hardened and may be poorly welded. Which means they’ll be much easier to crop. So although this chain is certainly going to scare off a casual thief, someone with a decent set of bolt cutters will probably find it easier to crop that a higher quality (and much lighter) 8 mm chain. A good 8 mm chain won’t be so cheap though!
I think the author of the article forgot the incredible 19mm chains offered by almax and 19.85mm protector chain but also you can custom order chain to whatever diameter going, a huge cruise ship is said to have a 150mm diameter chain!!!!!!!, so one link is likely to be a meter long!!!!! to look the same as these chains scale wise!!!, 25mm stainless steel boat chain is not uncommon either, personally i like the 15mm and above chain and u locks, why have anything less, remove bolt cropper threat and you get rid of 95% of potential thieves, if it’s a really rubbish bike they are more likely to steal the chain , just hope for the best ..
Hi James. Pragmasis themselves state that their 19 mm chains are a bit big for bicycles. I think there’s a danger they could actually damage the bike!
How are chains any better than U-locks if they are secured by a mini u-lock? Could a thief not simply turn an angle grinder to the small u-lock shackle and get through it just as easy as any other 14mm U-lock?
Hi Paul,
Yes a thief can go through a mini U-lock with an angle grinder just as easily as they’ll go through a standard sized U-lock or indeed a chain link. And it’s the same with bolt cutters if they’re big and powerful enough.
But mini U-locks are much less susceptible to leverage attacks and impossible to defeat with hydraulic bottle jacks. Which are techniques commonly used successfully on standard sized U-locks. So in that way they can be more secure.
The weakness with chains is usually the relatively thin links rather than the mini U-lock that’s used to secure them.
I hope that helps!
loved the article, thank you so much for writing it 🙂 it’s a joy to read articles like this that are about very specific topics and cover every consideration.
thanks again 🙂
I’m glad you found it useful Alexander!
Currently I have several Abus keyed alike padlocks ( https://www.abuslocks.com/p-476-3770rk-granit-series-steel-padlock.aspx) and disc locks (https://www.abuslocks.com/p-437-2080-diskus-padlock.aspx ) to secure my motorcycles and bicycles. If I am going to get the top quality Pragmasis 16mm chain what would be the minimum Abus padlock to use that maintains the 16mm chain security? Same question for Kryptonite 15mm New York Chain.
Good Question Jim. The Kryptonite 15 mm New York Chain usually comes with it’s own padlock. This is very secure and I would be tempted to stick with it. For the Pragmasis, I’d go with the Abus 37RK/80 GRANIT. Yes, the GRANIT padlocks cost more. But if you’ve got the best chain, you should pair it with one of the best padlocks.
Any thoughts on the Abus Bordo 6000? Thank you.
Hi Sal,
I talk about the Abus Bordo 6000 a bit on the home page. I think it’s a good mid security lock. Perhaps not quite as secure as mid security u-locks. But it has several advantages in terms of ease of use and practicality.
I talk a fair bit about folding locks vs u-locks vs chains on the home page. have a read and tell me what you think.
In summary, I think folding locks are a better alternative to most chains for portable security if a u-lock doesn’t suit your needs. And the Bordo 6000 is great for low risk areas.
I hope that helps,
Carl
Good article – thanks.
How do the Abus Granit 37RK/80 and Squire SS65CS-XLN compare?
Like Jim Haley, I already own & use some keyed-alike Abus locks, but I plan to supplement/augment my security with something VERY BEEFY (motorbike, not bicycle)
I’m looking at Almax Immobilisor Series IV or Pragmasis Protector 19mm. Both can be bundled with the Squire SS65CS, which I’m sure is a fine lock, but I’d like to maintain my one-key set-up if I can.
So – any comments or advice on how the Abus Granit 37RK80 and Squire SS65CS stack up against each other? If the Abus trumps or equals the Squire (in terms of effective security), I’d fork out for that. But if the Squire trumps the Abus I might settle for the reduced convenience.
Thanks for any responses,
Mark
Hi Mark,
I’d go with the Abus for convenience. I’m not an expert on either of these, but I know they’re both really good quality secure padlocks. The Abus has a thicker shackle but I doubt there’s much between them to be honest.
Thanks
Carl
Doesn anyone can explain why Kryptonite New York Chain 1210 is rated 9/10 and ART 4/5 when as padlock it uses mini version of my Evolution Series 4 LS U-Lock which is 8/10 and ART 3/5. This chain must be kind of joke.
Hi Luke,
I think this is because the Evolution Series 4 is more secure as a padlock than it is as a much bigger U-lock.
Why? Well because as a padlock it’s not susceptible to leverage attacks from crow bars etc and it can’t be popped open by a hydraulic bottle jack.
I hope that helps,
Carl
Personally as a second lock (first is Kryptonite Series 4 LS) I use MasterLock 8234 hardened steel chain, which is 90cm long and 10mm thick. Mini U-lock was working really poorly and I changed the padlock to GERDA S60 which has 12mm hardened steel shackle. I don’t know if this MasterLock chain is good, it has Sold Secure Silver award and measured link thickness varies from 9,5mm to 10mm. MasterLock is well known from making really crappy lock cylinders that aren’t pick proof at any way.
Yes, MasterLock is renowned for poor build quality! I don’t really recommend their bike locks on this site.
What do you think about using ABUS 12KS80 Loop Chain together with GERDA HSS closed 12mm hardened steel shackle padlock which is rated 4/6 according to PN-EN 12230:2013?
Yes that’s a pretty secure combination. The chain is 12 mm as well?
Yes, chain is 12mm thick. From what I noticed in XXKSYY, XX means thinkness and YY means length. XX can be 6, 8, 10, 12 or 14.
Ahh OK good to know, it must be pretty heavy to carry around with you though?
ABUS 12KS80 weigths about 2,5kg without padlock.
I own the Onguard Best 8016. It is not 16+ pounds, I’m aware the Amazon link quotes that too. It’s 6.2 pounds. I use it for my motorcycle, but have taken in to the beach, for my bicycle. I fear all those weights are not accurate.
Also what do you classify as small, medium, and large cutters? I would venture to say 40 inches plus for large.
I’m not sure where I got the weight for the 8016 from! OnGuard doesn’t publish weights so it’s difficult. But if the 8016 is 6 pounds the weight of the Kryptonite must be wrong too as they’re more or less the same length and thickness.
I would say 36 and 42″ for large.
So the way I initially weighed the lock was by going on my scale at home, with and without the chain. The difference was 6.2 lbs. Knowing this probably wasn’t most accurate measure, I took the lock to work, at the airport, and used a scale they use to measure luggage. The scale is checked quarterly by LA County Weights and Measurements. The lock weighed 1.5 lbs and chain 5.5 lbs , for a grand total of 7 lbs. The chain is approximately 44 inches long. I bought this chain in 2011, so it is older, and the Boxer X4P lock is not yellow/ black, it’s silver and black. Maybe it’s just an older version of the Beast. I do find it strange that Onguard doesn’t publish the weight on thier website. All in all your website is a very good resource.
what about the Ottolock?
Hi Vanessa,
The Ottolock isn’t a chain lock. I’ve yet to test it, but it looks like it might be a good choice as a secondary lock to secure your wheels or even as a cafe stop lock.
But I wouldn’t let any bike out of my site if it was only secured with the Ottolock.
Thanks
Carl
What about this chain “Schlage 999461 High Security Chain with Cinch Ring” and others by Schlage?
Yeah they look great Alexander. I’ll add them to the list!
The “Beast” was found wanting by YouTube content creator “Lock Picking Lawyer.” He demonstrated that it can be disassembled completely while locked and without the key, using a few simple hand tools. Just a heads-up.
Hi, I am looking to secure two e-bikes whee we go out and about with them. Value of bikes 2 x £1600. Would using a good quality u bolt to lock them together then a New York noose be a good combination? They will also be on a tow ball mounted bike rack when transporting them, any thoughts there? The e-bikes weigh about 18kg each thanks
Mmmm maybe. Depends on how risky the area is and how long you’d be leaving them for.
But to be honest I’d be tempted to use a u-lock and a chain on each bike. £1600 is a lot of money.
You could buy 4 locks but then mix them up and only use 2 if the risk level is lower.
Definitely secure them with a good chain (like the NY Noose) when they’re on the rack. So many bikes are stolen from racks. Usually because they’re locked really poorly (if at all).
But the NY Noose would do the job.
Does anyone remember the name of the company that offered a chain like thing? (solid chromium steel links) segmented like an armadillos tail?
The pointed tail end passed though a hole in the ‘head’ and a rotary key caused the lock to close down in-between the links.
I had one 20 yrs ago that I used to lock up my motorcycle when I went clubbing in Detroit.
If anyone tried to cut or remove it, I wouldn’t have known a there were no marks on it. I was going to some rough areas too, and leaving my motorcycle outside for hours.
I’d love to find one second hand, I’m sure the company folded, and no one has picked up the patent yet.
It was very heavy which gave it a double purpose, as it would break concrete pretty effortlessly without showing damage.
If anyone knows anything about, please let me know. I’d love to purchase one again. I’ve tried going so deep in Google that I run out of search pages
My name’s Gary and I can be reached at ggabrielkish@hotmail.com
Thanks
Sounds really interesting Gary. You used it to break concrete?!
It was called the Cobra Link. I’ve been looking for one myself. Hoping a lock manufacturer would buy the patent and start making them. Would make an excellent bicycle/ motorcycle lock. As its unusual, and a thief wouldn’t know how to tackle it.
hmm, I looked for this… and someone thinks it’s pretty valuable.. ebay@$280!!
http://www.ebay.com/itm/Rare-Vintage-Cobra-Links-Cobralink-5-ft-Heavy-Duty-Motorcycle-Chain-Lock-w-Key/223283253932
OTOH, it looks like it uses the circular key locks of that time that you could open with a BIC pen cap… so, maybe less secure than it looks.
Hi,
I got the Series 2 Kryptolok integrated chain recently, and I do like it. I use it combined with Fahgettaboudit mini u-lock, which I think is both a flexible and a secure arrangement.
I just am a bit puzzled, as I too thought the Series 2 integrated chain was Sold Secure silver-rated, but this article says that it’s gold-rated:
https://cyclingindustry.news/kryptonite-obtains-gold-sold-secure-rating-on-all-kryptolok-integrated-chains/
And I’ve seen it being gold-rated mentioned elsewhere. Wiggle, I think.
And this mentions it being harder to cut than the Series 2 u-lock, which surprised me:
https://thewirecutter.com/reviews/best-bike-lock/
Thought it might interest you. This is a very useful website, so glad to help, if I have helped!
Yes, confusingly I think there’s 2 versions of the series 2. A Gold and a Silver version!
That is confusing!
I have a chain question. I see many/most(?) security chains advertised as being 3t heat treated Manganese alloy (or similar terms), which is very tough and work hardens as you try to cut it… However, the literature I see on the web says it is NON-magnetic. So I tried a magnet against my Kryptonite KC890 bike chain and my 1/2″ Schlage 999461 High Security Chain with Cinch Ring AND they were both strongly attracted…. then I tried all my OnGuard and Kryptonite U locks.. and they were ALL attracted by the magnet. Am I missing something? Or are the manufacturers throwing around key words just to make their products sound more secure?
It’s the amount of Manganese alloy that you missed. The chain is a made with a very low amount of manganese and a higher amount of steel which is magnetic. Containing only between 12-14% Manganese it’s not surprising the magnet was still attracted.
Hmm, so you think this chain does NOT have enough Mn (11-14%) to be “non-magnetic” “Hadfield”/mangalloy work-hardening alloy steel, and thus is not as secure as high end abus or pewag or even kryptonite chains?? How can one determine this?
Hacksaw: A hacksaw can be quiet and can work through a nonhardened lock quickly. Most chains from the hardware store, cheap U-locks, and cable locks can be defeated with a hacksaw. The main drawback is that a hacksaw can be slow on a thicker lock, may catch and bind while trying to cut through a cable, and takes some physical effort to use in general. It is a very cheap tool to come by, though, and an easy one to carry and conceal. Bolt cutters: From my experience working in shops over the years, I’ve heard hundreds of stories of stolen bikes and seen many cut locks, and most of them (not including snipped cable locks) have been cut with bolt cutters. Bolt cutters can be quite small, usually 18 to 24 inches long. They’re quick to cut through a lock, cheap, portable, and easy to conceal. They don’t work on every lock, but for the ones they do work on, it’s only a quick snip and a free bike.
Hi Carl,
Thanks for a great site! Just a little note that the info about the hiplock gold on this page is inconsistent with the info on your chain lock comparison page. Here you state that it’s a 12 mm chain. According to the other page, and hiplock themselves, it’s a 10 mm chain with a 12 mm shackle on the lock. This seems consistent with the fact that it’s 1.15 kg lighter than the 12 mm Kryptonite NY noose despite being 10 cm longer.
Cheers!
The 11 mm and 13 mm chains from Pragmasis are also some really solid options. Bike theft just skyrocketed in my home town (I even found 2-3 solid u-locks that where cup open + a ton of destroyed cable locks), so I’m going to go for the 13 mm version, in combination with the 16 mm super compact u-lock Abus Power and a set of Hexlox.
Using the “Offcut Links” from the 11 mm and 13 mm chains will provide some very short, but super lightweight and strong chains.
I have two expensive bikes in front of my house. I can’t lock them anywhere because we don’t have a bike rack.
So I thought.
Which lock is better.If I buy a 16mm Gold rating lock or to go to a hardware store and buy myself a thick kettle and a plain lock so I can lock my bike. What do you guys think is better?
I’m not sure what you mean Mike.
Option 1: 16 mm Gold chain. What will you lock the bikes to?
Option 2: “thick kettle”? Do you mean a kettle bell? What kind of plain lock?
The way to remove all types of bike chain links like a complete master. First, look for the chain’s most vital part (Master Link) and place the pliers in a way that puts the two jaws in the holes on the link’s sides, make sure the master link is between the pliers’ jaws. Put pressure on the pliers to bind the jaws. After that, squeeze the link. Separate the link and the master pliers’ jaws by pulling them apart from the side portion of the link. When you want to put the chain back, you can just relink the rivets found at the chain’s end and secure it in place.
To know how to remove a link from a bike chain, you’ll also need the right tools that go along with a good set of instructions. When you are fully equipped, every step flows smoothly, and you can finish the task in no time.
Hello Carl,
Thanks a lot for your complete article.
I have a Kryptonite U-lock mini evolution 7 with its cable and I would like to complete my U lock with an another anti-theft for longer stops in the city (no overnight stays though).
I bought the Kryptonite Evolution 1090 chain 10mm but it’s quite heavy in addition to the U-lock… 🙁
Would a lighter 7mm chain (for example the Kryptonite keeper 785) be a good choice?
I also saw the Abus Iven 8210 chain (1,9 kg) in 8mm.
In the end, between the Kryptonite in 10mm and the Abus in 8mm there is 800g difference, is it really a gain ?
Can you help me ? 🙂
Hi Rémi,
The thicker the chain, the more secure it is. So yes, there is a difference in security between the Kryptonite 10 mm and the 8mm Abus.
However, if you’ve already got the Evolution 7, then maybe it’s enough as your main security and you’ll be OK with the Abus as a secondary lock.
It really depends on a whole load of other factors (the value of the bike, how long you leave it, how risky the area is).
Thanks
Carl
Hello Carl,
Thanks a lot for your reply !
I will keep the Krypotnite 10 mm, I think the extra 2 mm is worth the additional kilo. And I don’t think one kilo changes much for work cycling 🙂
The strongest chain lock should be Oxford beast 22mm chain + kryptonite Fahgettaboudit 18mm lock
Is the 12mm abus chain as strong as the pewag 12mm chain. I like the abus because it has the cinch ring I can pull the other end through.
Hi Peter,
Yes probably. I like the cinch rings as well!
Thanks
I have a new bike with a very thick frame (21mm). I got a Kryptonite New York standard u-lock as my mother had a spare. It just doesn’t fit around the frame of the bike and the standard size bike rack for London. Is a chain my only option then? I’m looking at the Kryptonite Evolution Series 4.
Do you have any recommendation on the length?Can I get away with the 90cm length? I usually lock my bike in the car park at my work, but I don’t have an assigned space so I can’t just leave the lock there or I’d get a bigger chain
Sorry about the late reply, Alberta.
You will be fine with the 90 cm Kryptonite Evolution Series 4.
You might even be OK with the 55 cm version; it won’t give you much more internal space than the New York Standard, but because it’s flexible, you should be able to get it around your frame, back wheel and a Sheffield style bike stand.
Is the parking area secure though?
Hi,
I’d mostly park it in the car park of my work place, which requires ID access and there are security guards and CCTV. Nothing is ever a guarantee when it comes to security which is why I would still feel more comfortable locking it up. The racks in the garage have a small hole to put the lock through and the D-Lock is just not really flexible enough, where as the chain lock would
Since this post, I have managed to get the Kryptonite New York standard U-lock to fit around the frame so I think it was just a lot of trial and error.
Thanks for the advice, and I will definitely get the Kryptonite Series 4 as well.