The best bike locks - U-locks and chain locks tested

Portable security cropped, cut, and hammered to sort the wheat from the chaff

Let’s get one important point across before we get into this bicycle lock group test: no lock is unbreakable or unpickable. Armed with the right tools, either to break or pick a lock, a person who really wants to steal your bike will be able to, no matter what you lock it up with. 

What you can do is deter the bike thief looking for an easy steal, or give the more determined thief a much harder time. And the better the lock, the harder time you'll give them, so we set out to find out: what's the best bike lock to buy?

First, one of the best bits of advice we can give you after many years of busting and picking locks in our bike lock tests, is: use two locks of different types from different brands. If a thief is adept at picking a certain type of lock and has the tools to do so, it’s less likely they will also have the tools or the knowledge to pick a completely different type. Two cheap bike locks that are wildly different in style and key/lock-cylinder types are sometimes better than a single expensive lock.

How we tested the bike locks

We’ve been breaking locks in our tests for years. We use tools and picks that are easily obtainable, and easily carried, and more importantly reflect what is being used to steal bikes out on the streets.

We use bolt cutters that can be carried concealed up a baggy sleeve (30in long) with cutting blades we shape and harden ourselves. We use the same methods that your lowlife bicycle thief is likely to employ, getting our tools from the same sources, and learning how to use them in the same way. You’ll understand why we don’t go into more specific detail…

Occasionally, when we get a lock we have a hunch is a little weak, we’ll have a go with a simple lump hammer first, mostly for the fun of hitting something really hard. We’ve never had good results with cans of compressed air and a hammer, so we no longer bother with that test. The important thing is, our lock test is one of the harshest in the industry that actually reflects the real world. If a lock lasts more than a minute with us, it’s pretty good.

What to consider when buying a bicycle lock

  • Make it difficult: If a thief is determined no lock will prevent your bike from being taken. Your aim should be to make it difficult. If it takes more time and makes more noise, your average thief is more than likely to look for an easier, quicker and quieter target. Fit your lock so it’s hard for you to get to the keyhole and fill the lock with as much bike and object as possible. These two simple things make them harder to pick, lever, crop or just plain hammer.
  • Keys: There are various types, but they all work a lock mechanism by moving pins or discs into a certain alignment to allow the lock plug to be turned by the key and the plug to operate the lock mechanism.
  • Protection: Nobody wants a bare metal lock clattering against their frame, so some protection in the shape of a rubber coating or a material sleeve will keep your bike looking good, and prevent the lock from corroding.
  • Shackle: We know it as the U-shaped part of a U-Lock or padlock. It’s called a shackle because that’s exactly what it does: shackles two things together. In our case, it’s shackling our bikes to something sturdy.
  • Links: Chains are made up of links; hoops joined together. The smaller the internal diameter of the links the better, as this gives less space for a lever to be inserted. It also gives chain locks their flexibility, adding versatility.

Bike U-locks: the best and worst

Abus Granit X Plus 540

This is a heavy lock, but it's one of the best ever
This is a heavy lock, but it's one of the best ever

  • Price: £90 / US$150 / €105 / AU$235
  • Weight: 1527g
  • Internal dimensions: 230mm x 108mm
  • Bolt crop test: Passed
  • Portable cutter test: 2 minutes 12 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score4.5/5

For a lock weighing just over 1.5kg this performs like a beast. The internal dimensions are just about perfect for filling with frame, rear wheel and front wheel and offering up just enough to fit around standard street furniture to completely fill the lock. 

You will struggle to fit it around a wide base lamppost though with all that in it. In the tests no amount of hammering or levering touched this (it just kept springing back, and still remained usable), and considering the weight, even our cutting test took a respectable length of time. 

We did manage to pick this lock, once, after about two hours of messing around – but we were unable to ever repeat that miracle feat. If weight and security are the balance you're looking for, there's little to come close to being as good as this.

Verdict: You’re carrying over 1.5kg of steel, but the Granit X Plus 540 is a typically impressive lock from Abus – and one of the best U-Locks ever

Abus Bordo Granit X Plus 6500

A tough lock that folds up neatly to stow on your bike
A tough lock that folds up neatly to stow on your bike

  • Price: £100 / US$170 / €130 / AU$235
  • Weight: 1607g
  • Internal dimensions: Wobbly
  • Bolt crop test: 18 seconds
  • Portable cutter test: 22 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score4/5

Articulated link locks are useful as they offer the shape changing and fill-ability properties of a chain while having a structure that folds into a neat "box" shape for easier stowage/carrying (it comes with its own rubbery frame mounting "pocket"). 

You can fill this lock with the frame, front and rear wheel, and still have room for a lamppost. The weak spot is always going to be the links though, and bolt croppers quickly popped this open. But, if you combine this lock with a small 'true' U-Lock then its expanded size and versatility quickly begin to show their benefits. 

The links are reasonably kind to your bike, but as with any lock you are still going to have to be careful if you want to avoid marking your frame.

Verdict: The 6500 is a good performer, but versatility is the thing

Hiplok DC

This is a tough little lock for the weight
This is a tough little lock for the weight

  • Price: £60 / US$94 / €85 / AU$120
  • Weight: 1109g
  • Internal dimensions: 130mm x 70mm
  • Bolt crop test: Passed
  • Portable cutter test: 43 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score4/5

For a lock weighing a little over 1kg this is quite a tough little thing. The shape is nice and gives just enough room for a couple of wheels and a frame while allowing most bicycle racks and slimmer street furniture to be used as an object to lock to. 

It is well protected, too, probably the kindest lock against a bike in this test, and there's a good rubber cover over the lock mechanism that seals it very well and does a good job of keeping everything out of the vulnerable lock mechanism. 

The additional included wire loop is about a strong as a length of string though, serving as a visual deterrent only and standing up to a pair of wire cutters (yes, wire cutters, not a bolt cropper) for all of a second. We have one of these in regular everyday use and there has been next to no corrosion where the lock shackle fits into the main lock body either.

Verdict: Don't rely on the supplementary wire loop, but the main lock is impressively gritty for its weight

Kryptonite NewYork Fahgettaboudit Mini

This is a small lock with a lot of metal in it
This is a small lock with a lot of metal in it

  • Price: £80 / US$114 / €111 / AU$150
  • Weight: 1993g
  • Internal dimensions: 150mm x 83mm
  • Bolt crop test: Passed
  • Portable cutter test: 2 minutes 40 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score4/5

At nearly 2kg there is a lot of metal in this small U-Lock, which explains why the cutting test took so long. The drawback, though, is the size. There was no way we could get a frame and two wheels into this and have enough room for locking it to anything other than a 9cm diameter pole or smaller. 

If you're locking to most standard bike racks found in towns then it'll work – only just, but the good thing is it will certainly fill the lock. But if you're looking to lock to anything bigger or you're running fatter rubber, you'll need the longer version. 

We have heard about being able to pick these locks, but despite our best attempts as not entirely beginner lock pickers we couldn't manage it. We know from experience that the ends of the shackle where they fit into the main lock body have a habit of getting a little rusty and sticky, but this is easily cured by wiping with a bit of lube and a cloth every week.

Verdict: Don't expect the Fahgettaboutit Mini to accommodate much. Do expect what you squeeze in there to still be there when you get back.

Kryptonite Messenger Mini

A good value but only moderately secure lock
A good value but only moderately secure lock

  • Price: £45 / US$75 / €52 / AU$120
  • Weight: 1141g
  • Internal dimensions: 170mm x 95mm main + 95mm x 86 mm rear wheel
  • Bolt crop test: 58 seconds
  • Portable cutter test: 1 minute 36 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score3.5/5

A U-lock with an extra U on it is a simple idea (one which we've done before with two U-Locks of different brands interlinked) but it works quite well. Simply open the lock and slide the extra U off, stick it through the rear wheel, slide the main U through it, stick in your front wheel, and lock it all up. 

If you're locking to larger diameter objects the space freed up by the rear wheel being on its own U shackle is a welcome bonus. At under a minute to crop through, though, this is a lock for convenience use in areas where there are always going to be people around. 

It is not a high security lock, which is clear from where it sits in Kryptonite's range, and with that in mind we'd love to see a New York security level version of this.

Verdict: Good value, and the second shackle frees up space for the main lock, but only average toughness

Knog Strongman

A solid, well thought out lock
A solid, well thought out lock

  • Price: £80 / US$100 / €90 / AU$110
  • Weight: 1156g
  • Internal dimensions: 140mm x 83mm
  • Bolt crop test: Passed
  • Portable cutter test: 1 minute 20 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score3.5/5

Don't let the Knog styling put you off from what is hidden within. We were surprised at how tough this thing was. 

Although the internal dimensions are similar to the Kryptonite New York Mini, the square-ish shape of the shackle makes all the difference when it comes to locking a bike and two wheels up. That little extra room in the corners allowed us to use this lock in more places by putting the wheels up in the corners and the seat tube of the bike sitting between the wheels. 

Combine that small bonus of versatility with low weight and a soft rubber covering that is kind to any bike and you have a worthy little U-Lock indeed. Like some other U-Locks in the test though it suffered from rust and sticking on the ends of the shackle, so a wipe with an oily rag every week to prevent this from happening. Also... don't expect it to stay very white for very long.

Verdict: Stylish but solid and well-thought out little lock

Squire HammerHead 290 Combi

Combination locks don't need a key - but then a thief doesn't need a key to open them
Combination locks don't need a key - but then a thief doesn't need a key to open them

  • Price: £54 / US$108 / AU$ TBC
  • Weight: 1779g
  • Internal dimensions: 290mm x 106mm
  • Bolt crop test: Passed
  • Portable cutter test: 48 seconds
  • Picked: 38 seconds
  • Hammer: Passed
BikeRadar score2/5

Combination locks are handy as you don't have a key to lose. But, they're always going to be susceptible to picking. There's a trick to this one, but once learned it doesn't take too long to open (from unknown codes set by somebody else). 

The shackle itself didn't stand up to cutting well either, and although the generous internal dimensions make this a versatile lock for using almost anywhere, we would only ever recommend it when used with another lock of a different type if you're looking for higher security (something we highly recommend and something we do a lot ourselves). 

The combi lock mechanism never got hard to operate despite jetwashing and filling it with grit, although the cylinders' smooth surfaces make it hard to use wearing gloves.

Verdict: Generously proportioned, but also fairly generous to thieves – recommended as a secondary lock only

Squire HammerHead 230 Key

This lock is a good size but it won't protect your bike for long
This lock is a good size but it won't protect your bike for long

  • Price: £50 / US$68 / AU$TBC
  • Weight: 1649g
  • Internal dimensions: 230mm x 106mm
  • Bolt crop test: Passed
  • Portable cutter test: 47 seconds
  • Picked: 29 seconds
  • Hammer: Passed
BikeRadar score2/5

With seemingly the same material and diameter shackle as the HammerHead 290 Combi we could cut this in just one second less. We also managed to pick it (and we suck at picking more traditional style locks). 

The size is good, though, with enough room for most street furniture and two wheels and a frame. In combination with a short chain from Squire such as the Mako 8mm Integrated it would make a good setup, although we would always suggest another lock of different brand and style to present the would-be-thief with two different lock mechanism types (something almost every company represented in this test agrees with, despite the fact from their point of view it means you buying a competitor's product).

Verdict: Good as part of a two-lock setup, mediocre on its own and susceptible to picking

Bike chain locks: the best and worst

Abus Granit Power XS

This monster was the toughest on test
This monster was the toughest on test

  • Price: £120 / US$160 / €155
  • Weight: 3368g
  • Length: 1200mm
  • Bolt crop test: Passed
  • Portable cutter test: 2 minute 40 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score4.5/5

At nearly 3.5kg this is a monster. But it is a monster that stood up the best in all of our tests. The padlock is engineered as well as the chain, there is no weakest link with this setup, and that's what makes it perform as a complete system rather than a chain and padlock. 

Yes it is heavy, yes it is long, but they don't come much better than this. If you're locking to large objects, more than one bike at once, and want to wrap through wheels and frame, this is the answer. 

We happily use one of these as standalone security on three bikes and a ground anchor. The weight is the drawback to carrying this thing around – but then you have to ask yourself if that weight in your bag is worth more than your bike. Like us, you are probably happy to put up with the weight as a sacrifice for security.

Verdict: A beast of a chain lock – you may need muscles to carry it, but it won't let you down

Hiplok Gold

A tough lock that weighs less than the Granit
A tough lock that weighs less than the Granit

  • Price: £85 / US$133 / €121
  • Weight: 2570g
  • Length: 850mm
  • Bolt crop test: Passed
  • Portable cutter test: 2 minutes 30 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score4/5

Wearing a big-link chain around your pelvis when riding a bicycle is something you have to make your own mind up about with regards to your own safety. We're not getting into health and safety issues concerning that issue, though, we're testing the security of it when used as a lock. And boy does it do well. 

It was only bettered in the test by the excellent Abus Granit Power, weighs just a little over 2.5kg, and is a very usable length. All in all, as a chain light enough to carry around and with an almost perfect length, there isn't much better than this. 

We are pretty sure we managed to get close to picking it, but it took ages (in excess of an hour of fiddling around), and even an experienced friend of ours who works in the lock industry gave up after 30 minutes by saying: "I'd probably get it eventually, but you'd end up only learning that lock, you'd have to learn another one and that takes time". So essentially, you would have to learn each individual Hiplock 'key' to be able to pick them quickly.

Verdict: Very tough and portable bike security – provided you’re happy carrying around 2.5kg of metalwork

OnGuard Mastiff

There's little to choose  between the OnGuard and the Abus chain locks
There's little to choose between the OnGuard and the Abus chain locks

  • Price: £65 / US$95 / AU$TBC
  • Weight: 3493g
  • Length: 1300mm
  • Bolt crop test: Passed
  • Portable cutter test: 2 Minute 20 seconds
  • Picked: Passed
  • Hammer: Passed
BikeRadar score4/5

Having previously had hammer success with an OnGuard 8002 we tried the same method on the Mastiff, which has very similar construction... and we failed, miserably. 

It wouldn't crop or pick, and it stood up to the cutter almost as well as the Abus chain. We even had a go at levering the links, because we've never tried levering an OnGuard chain. That didn't work either. 

So aside from cutting just a little quicker than the Abus padlock, there is little to choose between them aside from the quality, frame protection, and weather sealing, where the Abus just (only just) edges it out. 

The extra 100mm of chain doesn't make much difference in the real world aside from increased weight. But as with the Abus chain, the extra security is something we'd happily trade against a bit of extra weight. 

Good chain systems are always going to be heavy – as soon as you come to terms with that you realise that security is the important thing, not weight.

Verdict: Very tough and good value chain lock that's up there with the best

Squire Mako CN8/900

Combined with a small U-lock, this would be a great secondary line of defence
Combined with a small U-lock, this would be a great secondary line of defence

  • Price: £40 / US$55 / AU$TBC
  • Weight: 1693g
  • Length: 900mm
  • Bolt crop test: 19 seconds
  • Portable cutter test: 36 seconds
  • Picked: 3 minutes plus
  • Hammer: Passed
BikeRadar score3/5

Despite using similar lock internals to the HammerHead 230 U-lock, it took us longer to pick this. We also managed to spot a weakness and exploit it with the croppers. In the cutting test, though, it stood up surprisingly well. 

The length is about perfect for a couple of bikes, and what extra length you have when used on one bike is easily sorted by wrapping around the bike/object to minimise slack. Combined with a small U-lock, this would be a great secondary line of defence. 

We didn't have any problems with corrosion, and just like any other chain it is easily bundled up in a bag or bag pocket for transportation purposes.

Verdict: Not quite sturdy enough for us to recommend as a standalone, but cheap and will work great as part of a two-lock combo

Kryptonite Messenger Chain

The Kryptonite Messenger is let down by its padlock
The Kryptonite Messenger is let down by its padlock

  • Price: £65 / US$85 / €59 / AU$140
  • Weight: 2845g
  • Length: 1000mm
  • Bolt crop test: Passed
  • Portable cutter test: 28 seconds
  • Picked: 3 minute
  • Hammer: Passed
BikeRadar score3/5

Despite the heft weight of the chain, the weak spot in the Messenger is its somewhat lacking padlock. Taking this chain and adding a good quality padlock would make a great product, but Kryptonite has specced a lock that simply cannot stand up to a cutter very well at all. In addition to that we were able to pick it with a little practice. 

It's a shame, as the chain is pretty good and represents typical Kryptonite quality, but any chain is only as good as what shackles the ends together. There is always going to be a weak spot on any lock, no matter what design it is, but for it to be such a contrast to the excellent chain is not something we have come to expect from Kryptonite.

Verdict: Superb chain let down by the padlock holding it together

Final verdict: what's the best bike lock?

Our lock test is one of the harshest around. We shape our own bolt cropper blades, use the best cutting discs and learn how to pick locks. We do what any high-end bike thief would do. We set a limit of five minutes to crack a lock, and we’ve never failed. With that in mind, anything that scores over three can be seen as a good lock.

It’s no surprise to see the usual suspects topping the honours list, but Kryptonite and Abus have been joined by Hiplok, which has produced the excellent ‘mini’ DC and wearable – if heavy – Gold, and we were also very impressed by OnGuard’s Mastiff chain.

It’s Germany’s Abus that takes both top spots, though. Its 3.5kg Granit Power XS chain takes portability to its limit, but it is very, very tough. The ultimate accolade, though, goes to the Granit X Plus 540 U-lock, belying its middleweight status with a heavyweight performance. A good size, superb design and very strong – what more do you want?

This article was originally published in Cycling Plus magazine, available on Apple Newsstand and Zinio.

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