We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies. You can understand more and change your cookies preferences here.

Cars & travel.

6 October 2021

Best bike locks for 2021

A bike lock only has one job to do – stop your bike being stolen – and it has to do it well. We've thrown all the lock-breaking tools at our disposal at a selection of leading bike locks to help you choose the best bike lock.
SM
Sam Morris
cyclist locking bike with u-lock

A strong bike lock can make the difference between your ride home being secured, and that sinking feeling when your bike isn't where you left it. Securing your bike with a great bike lock will not only thwart thieves' attempts to steal your bike, it could even put them off trying in the first place. 

But when many bike locks look pretty similar, it can be tricky to know in advance which ones are up to the job and which will let you down. So our lab experts have posed as wannabe thieves, using bolt cutters, angle grinders and other lock-breaking tools to identify the locks that will keep your bike safe. 

We've also checked how easy they are to transport and use. Nobody wants to be wrestling with an unwieldy bike lock in a torrential downpour. 

A Best Buy bike lock will be easy to use and offer good security against even the most powerful tools – meaning a thief is likely to be spotted and interrupted when trying to steal your bike, or just give up. 

Read on to discover the pros and cons of different types of bike lock, which bike locks made the grade in our tests, plus our top tips on how to buy the best bike lock. 


How to buy the best bike – if you're in the market for a new bike, check our expert guide to getting the bike to suit you.


What's the best type of bike lock? 

Security experts recommend using two different types of lock to secure your bike, one of which should be a U-lock, according to the Met Police. Different lock types need different tools to break, so using more than one lock type is likely to slow a thief down. 

If you're buying a bike lock for the first time, you may be baffled by what type to go for. Read the key things you need know about the main types below, or go straight to our bike lock reviews if you know what you're after.

U-locks (or D-locks)

U-lock bike lock

This lock gets its name from its rigid, 'U-shaped' body. U-locks vary in size, strength and weight, but are generally regarded as the most secure type of lock. 

For this security there is sacrifice in flexibility. You need to be able to fit the rigid lock around your bike's frame and wheel plus the object you're securing your bike to, so check before you buy that it's the right size for your bike.

Chain locks

bike chain lock

Chain locks are made up of a series of hardened steel links, usually inside a protective sleeve. They can offer similar levels of security as U-locks, but they have pros and cons by comparison. 

They're more flexible than U-locks so are easier to wrap around tight areas of a bike and secure it to a wider range of objects. But they tend to be heavier than similarly secure U-locks and are more likely to rattle if attached to your bike frame while cycling. 

Folding locks

Bike Folding Lock

Folding locks consist of several solid steel arms, joined together by steel rivets. They fold up into a compact size, making them easy to transport in a bag or on the bike frame, but open up to a larger area than many other locks. This can make them a good choice if you have a large bike or need to secure it to thick object. 

However, the multiple hinge points on a folding lock are potential weak spots that can be easier for a thief to break. Our tests aggressively attack the hinge points, though, so you can be sure a high-scoring folding lock still offers great security.

Textile locks

Bike Textile Lock

Textile locks are made up of tough composite textiles, usually around a metal core. They offer security along with flexibility at a lower weight.

Some are designed to be worn around the waist like a belt when not in use, making them easy to transport while cycling.

This security and flexibility come at a cost – other types of lock will give a similar level of security for less.

Cable locks 

Made from intertwined metal fibers with a plastic coating, cable locks come in a wide variety of sizes, weights and locking mechanisms. They're flexible and tend to be available in longer lengths than chain locks.

Their flexibility and light weight come at the cost of being the least secure type of bike lock. They may deter an opportunist, but a persistent bike thief will get through one relatively easily. 

As such you shouldn't rely on a cable lock as your main bike lock, but you could consider one as a secondary lock, as a cheaper extra layer of defence for a wheel, for example. 

Bike lock reviews

We've grouped our reviews by lock type to help you easily select the best for your needs, but all of the scores are comparable across tables (so a chain lock that scored 70% would be equally secure as a U-lock with the same score, for example).

Only logged-in members can view our full bike lock reviews. If you're not yet a member, sign up to Which? today for instant access to this and all our reviews.

U-lock bike lock reviews

Abus Granit Plus 640 (typical price: £60)
Abus Granit Plus 640
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Internal length x width
Diameter of shackle (ex. plastic coating)
Type of locking mechanism
Number of keys
Bike mount included?
797g
151mm x 83mm
12mm
Lock and key
2
No

Weighing just under 800g, the Abus Granit Plus 640 is one of the lightest bike locks we've tested. Combined with its small size, this could make it an appealing choice for the cyclist who wants an easy-to-transport U-lock – though there's no bike mount included.

But does its petite size come at the expense of security?

Sign up to Which? to find out how well it stood up against our expert lock-breakers.

Axa Newton Pro 190 (Typical price: £35)
AXA Newton Pro 190 59502595SS
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Internal length x width
Diameter of shackle (ex. plastic coating)
Type of locking mechanism
Number of keys
Bike mount included?
1,382g
190mm x 102mm
14mm
Lock and key
2
Yes

The Axa Newton Pro 190 is a full-sized, mid-weight U-lock, and it comes with a bike mount for ease of transport when cycling.

But what really matters is whether it will protect your bike against a determined thief. 

Find out if our expert lock-breakers managed to crack it – sign up to Which? to see our lab test results.

Kryptonite New York Fahgettaboudit Mini (Typical price: £120)
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Internal length x width
Diameter of shackle (ex. plastic coating)
Type of locking mechanism
Number of keys
Bike mount included?
2,050g
157mm x 82mm
18mm
Lock and key
3
No

The Kryptonite New York Fahgettaboudit Mini is a small U-lock, though at just over 2kg it's one of the heaviest bike locks we have tested.

The manufacturer rates the security of this bike as 10 out of 10, with a locking cylinder that protects the lock against dirt. But did its security claim hold up when we put the lock through our rigorous lab tests?

Sign up to Which? to find out if this is the bike lock for you.

Trek U4 Mini (typical price: £30)
Trelock U4 Mini
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Internal length x width
Diameter of shackle (ex. plastic coating)
Type of locking mechanism
Number of keys
Bike mount included?
741g
147mm x 85mm
12mm
lock and key
2
Yes

Weighing in at just under 750g, the U4 Mini is one of the lightest bike locks we have tested. Combined with its small size and the included bike mounting bracket, this makes it extremely easy to transport.

But does it fulfil its main function of securing your bike effectively?

Sign up to Which? to find out if this is the bike lock for you.

Chain bike lock reviews

Hiplok Gold High 10mm Chain Lock (Typical price: £50)
Hiplok Gold High 10 mm Chain Lock
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Length of chain
Thickness of chain
Type of locking mechanism
Number of keys
Bike mount included?
2,406g
800mm
10mm
Lock and key
3
No

This chain lock weighs in at around 2.4kg, making it one of the heaviest locks we've tested, although its long length means it'll easily fit around your bike frame, rear wheel and whatever you're securing it to. 

Does this extra weight provide extra security?

Sign up to Which? to find out if this lock secures your bike against typical tools used by thieves.

Folding bike lock reviews

Abus Bordo Big 6000 (Typical price £60)
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Length of lock (unfolded)
Thickness of shackle (ex. plastic coating)
Type of locking mechanism
Number of keys
Bike mount included?
1,390g
1,115mm
5mm
lock and key
2
Yes

The Bordo Big 6000 is more than one metre long when unfolded, making it easy to secure both your frame and wheel to even a thick bike rack post.

It folds down to a compact size and even comes with a bracket to mount to your bike frame. 

But will it keep your bike safe from thieves? Sign up to Which? to see if it held up against our tough security tests.

Kryptonite Kryptolok 685 (Typical price £60)
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Length of lock (unfolded)
Thickness of shackle (ex. plastic coating)
Type of locking mechanism
Number of keys
Bike mount included?
1,078g
810mm
5mm
Lock and key
2
Yes

Weighing in at just over 1kg, the Kryptolok 685 is a pretty lightweight lock for its size – 810mm long when unfolded.

But does it secure your bike effectively?

Sign up to Which? to find out if this is the bike lock for you.

Textile bike lock reviews

LiteLok Gold Wearable Large (Typical price £110)
Litelok Gold Wearable Black
Ease of use
Durability
Overall strength
Security against hand tools
Security against lock picks
Overall score
Weight
Length of lock
Thickness of shackle (ex. plastic coating)
Type of locking mechanism
Number of keys
Bike mount included?
1,408g
972mm
9mm x 51mm
Lock and key
2
No

This textile lock can be worn around the waist for ease of transport while cycling. It weighs around 2.4kg, making it one of the heaviest locks we've tested. 

But does this extra weight provide extra security?

Sign up to Which? to find out if this lock secures your bike against typical tools used by thieves.

What features should I look for in a good bike lock?

As we've highlighted above, there are many types of bike lock to choose from, with certain locks suiting different cyclists. Secure by Design (the official police security initiative) recommends you lock your bike with at least two locks, one of them being a U-lock.

Deciding on the other type of bike lock to purchase generally comes down to your own preferences, but there are some features worth looking out for across all types of bike lock, as they make it harder for skilled thieves to beat it. 

  • Hardened steel – a heat treatment that makes steel tougher to break.
  • Deadlocks – a type of key lock that is harder for thieves to force open.
  • Pick-resistant locks – these locks have extra mechanisms in the lock barrel, essentially making it much harder for a thief to pick the lock.

Looking to kit out a new bike with a full suite of accessories? If you're planning on cycling after dark, check our guide on how to buy the best bike lights.

Should I buy a key or combination bike lock?

Bike five barrel combination lock

For maximum convenience, combination locks usually trump key locks, as you don't need to remember to bring the key. You will, however, need to remember the code – not necessarily that easy if you don't use your bike that often. 

Combination locks are often regarded as less secure, however, because:

  1. An observant thief could spot your code as you lock or unlock your bike. To reduce this risk, make sure you shield the code from observers when you enter it. 
  2. A combination lock can be 'hacked' without tools. A key lock needs brute force or tools to break it; a combination lock can, in theory, be cracked by trial and error. 

It would take a determined thief less than an hour to work through all of the unique combinations on a three-digit lock – far from impossible if your bike is tucked away in a quiet location. We recommend opting for a lock with at least four digits, which increases the number of possible combinations, and the time it would take to try them all, tenfold. 

In practice, a decent combination lock with at least four dials and built-in anti-lock-picking features will offer similar levels of protection to a decent key lock.

An example of an anti-lock-picking feature is 'false gates'. These make it 'feel' to a thief like they have found the right combination, but doesn't allow the lock to open. It will take a thief much longer to beat a false-gated lock.

Can I get away with a cheap bike lock?

Bike locks prices range from around £5 for a basic cable lock, to more than £100 for a big-brand U-lock. 

The cheapest bike locks are usually cable locks. While these are better than no lock at all, most thieves will be able to make short work of them. You shouldn't rely on a cheap cable lock as your main lock.

The bike locks we've tested range in price from £30 to £120, including a Best Buy for less than £60. While in general the more expensive the lock, the more secure it will be, you don't have to pay a fortune either. 

Is there a bike lock that cannot be broken?

The short answer is no: no lock is unbreakable. 

The aim of bike locks is to make your bike as unappealing as possible, deterring thieves from even trying to nick your bike. You should use two locks to secure your bike, with one of them being a U-lock.

Our tests have found that the best bike locks, while not unbreakable, will stand up to angle grinders, saws and bolt cutters for several minutes. This will stop an opportunist successfully breaking the lock, and make it more likely a professional will give up or be interrupted when trying to break the lock.


A lock is only as good as how and where you secure your bike – read our guide on how to secure your bike.


Bike lock security ratings explained 

Manufacturer security ratings

Bike lock manufacturers typically grade the security of their locks on a scale of one to 10. This can be useful when comparing the different locks within a single brand.

However, different manufacturers use different scales, as well as different criteria to measure their locks' security. This means it's not possible to use manufacturer ratings to directly compare the security of locks across brands.

Our bike lock reviews are based on assessments and criteria that are comparable across all of the locks we test, so you can feel confident that the locks that score the highest are genuinely the best. 

If you're interested in a bike lock we haven't yet reviewed, check its security rating by an independent body such as Sold Secure. 

Sold Secure bike lock ratings

Sold Secure Logo

Sold Secure is a third-party certification body that rates locks. Many insurance companies recognise its safety ratings, so getting (and using) a lock with this certification can may help lower the cost of bike insurance.

There are four Sold Secure ratings; the higher the rating, the more secure the lock – though you're likely to also find that, in general, the highest-rated locks are the most expensive.  

  • Bronze – the lock offers defence against opportunistic thieves
  • Silver – the lock is a good compromise between security and cost
  • Gold – the lock offers a high level of security, aimed to secure mid to high-value bikes
  • Diamond – the lock offers the highest level of security, aimed at securing high-value bikes and electric bikes

Best rechargeable front lights – stay safe on the road with the best rechargeable bike lights you can buy


How we test bike locks

cutting bike lock with bolt cutters

We test every bike lock based on criteria stipulated in a British Standard: for the geeks among you, it's BS EN 15496:2008 Cycles. Requirements and test methods for cycle locks. 

What this means in practice is that we throw everything including the kitchen sink into testing a lock's security, as well as assessing how easy to use and how durable it is.

Overall strength

We test each lock's resistance to being cut, pulled apart and hit by machines under strict lab conditions. This ensures that each lock's strength has been tested in the exact same way, giving an objective measure of how tough each lock is. 

  • Cutting test – can the lock be cut by a force of 55kN? That's about two and a half times the force that a standard bolt cutter can apply.
  • Tensile test – can the lock be pulled open by a force of 10kN? That's about the equivalent of two adults hanging from the lock.
  • Impact test – can the lock be broken by a 3kg impact device? We drop the impact device on the lock five times in 90 seconds.

Locks that pass all these tests are really tough locks, meaning they will stop an opportunist and slow down a professional thief – to the point where they are likely to be interrupted or give up trying to beat the lock. 

Security against hand tools

We then test each bike lock in a real-world situation. A bike is secured with the bike lock and we give an expert lock breaker three minutes to beat the lock using selection of tools that a professional thief might have access to.

The specific tools we use are targeted around each type of lock, but include bolt cutters, nippers, saws and lock picks – even a battery powered angle grinder, our toughest tool.

If our experts can't break the lock in this time, or if the locks last at least a couple of minutes against the angle grinder, you can feel pretty confident that the lock will protect your bike from thieves. 

Ease of use

We access the lock for how easy it is to use and transport, including:

  • Can the lock be mounted to the bike?
  • How smooth is the locking/closing function of the bike lock?
  • How much does it weigh?
  • How noisy is the bike lock when cycling?
  • How durable is the lock? - we spray each lock with salt solution to replicate several tears of weather exposure

How is the Which? score calculated

Each test we perform factors into the final score for each bike lock. To be a Best Buy a lock needs to score at least 80%, meaning it provides a great level of security against lots of different attacks, while still being easy to use. The overall score is:

  • Overall strength (40%)
  • Security against hand tools (25%)
  • Ease of use (35%)

Planning to get on your bike more and boost your fitness? Keep track of your progress with a Best Buy fitness tracker


Tables last updated 6 October 2021