Best bike locks 2024: heavy duty and portable locks for keeping your bike safe

A good quality bike lock is an effective deterrent to thieves and essential if you plan to commute by bike, leave your bike out of sight or just keep it safe at home. 

We have tested hundreds of bike locks over the years here at Cycling Weekly. Ranging from heavy-duty U-locks and chain locks for securing bikes at home and train stations, to portable lightweight options for bikepacking and peace of mind at the café stop.

We extensively test the useability, function and features of all the locks we test, until we need to bring in the power tools. Here in the UK and North America, Sold Secure does this for us, along with ART in Europe. They independently test bicycle locks, classifying them using a simple rating system based on their performance. For each review, we list its security rating and for more details about the Sold Secure rating system head to the bottom of this page.

A good bike lock shouldn't be the only thing that keeps your bike safe. Consider installing a bike tracker, so at the very least if your bike is stolen, it is more likely to be recovered.   

Best bike locks: quick list

Best bike locks: Our pick

Best U-Locks

The Litelok X1 isn't cheap. With the premium price, however, comes premium quality. The lock is diamond rated meaning you'll be covered under most insurance schemes, it requires multiple angle grinder discs to penetrate and weighs in at a reasonable 1.7kg, meaning that the lock is easy to carry around.

In use, our reviewer found that: "Due to its locking circumference, it was easy to lock the bike up in all of the different places that I needed to and in general, the Litelok X1 was a pleasure to use". 

There are other locks, such as the On Guard Brute, which offer a similar security rating for a much lower price, but the security ratings only provide a lower bound - they don’t tell you much a lock passes the test by.

So, for ultimate peace of mind - when it’s the bike you care about, rather than insurance provider box ticking - the X1 is an excellent option. It's constructed with 'Barronium', a brand new composite designed to resist angle grinders and lined with an environmentally friendly rubber coating that will not scratch your frame.

Read more: Litelok X1 bike lock full review

Manufactured by Milton Keynes based security brand, Milenco, the Dundrod ++ surpasses the requirements for Gold and is one of the few locks that meet Sold Secure’s Diamond standard.

Although most bike insurers will only require a Gold rated lock for cycles worth over £1,000/$1,000, if your bike has sentimental value or is a model that can’t be replaced, you’ll be wanting something more secure — which is where a Diamond rated lock comes in.

The Dundrod ++ is reassuringly plump with a shackle and crossbar that are visibly beefier than a standard U-lock. The lockable area is on the larger side for this style of lock, making it quite easy to secure the bike through the frame and wheel.

Bear in mind that if you are considering a lock of this application, it is worth using two to lock each wheel to the frame and immovable object, as well as potentially upgrading the locks to wherever you are keeping your bike.

Coming without a bike mount and weighing just under two and a half kilos, the Dundrod ++ isn’t intended as a lock for use when out and about—although this certainly isn’t ruled out, providing you have somewhere to put it.

Read more: Milenco Dundrod ++ full review

The Granit Xplus 540’s 23cm shackle height and 10.8cm inner width means you have plenty of room to maneouver. While it doesn’t offer quite as much flexibility as the brand’s Bordo folding lock, it still allows for a variety of locking possibilities. 

Its Diamond rating is secured through a combination of 13mm temper hardened steel square parabolic shackle and a double bolting shackle and lock body, with the latter designed to deliver protection against picking. The lock also has the feel of something that’s well-made and features an automatic keyhole cover; having had a couple of locks jam on me in the past, this is worthwhile detail. 

It comes with a flexible mounting point that allows it to be attached to the top, down and seat tube - depending on your frame of course. It’s certainly light enough to carry in this manner, although like all ‘full-size’ U-locks it’s likely better stored in a backpack. Its security rating also makes it another consideration for home use.

A brilliant low-cost option, making Gold Sold Secure even more accessible to everyone. At this price, it wouldn’t even be too much of an outlay to buy one for every bike in your household. Although it might be tempting to use one lock to secure multiple bikes, especially if you have a longer chain link lock, that only serves to tempt thieves. Far safer to have locks for each one.

At just under 1.3kg, the K-Traz U17 is surprisingly lightweight—especially considering its price and security rating. A complete plastic coating minimizes the risk of paintwork coming into contact with metal.

The two downsides are the straight shackle, which does make it more difficult to mount the crossbar than a bent design, and the plasticky bike mount. We found this a little fiddly to set up, as it uses two long screws to clamp the bracket to the frame, and the release mechanism for extracting the lock feels a little flimsy which makes it a bit of a struggle to dismount the lock.

For the money, we think the K-Traz U17 is a brilliant lock, but if you’re after quality all-round performance, you will need to set your price bracket a little higher.

Read more: Zéfal K-Traz U17 full review

Best Mini U-Locks

The Master Lock Mini U-Lock is something of a hidden gem. You’d have thought that with the top Sold Secure Diamond rating and its impressively light sub-kilo weight Master Lock would be boasting and inflating the price to match those premium qualities.

But no, despite being one of the lightest locks on the market with a Sold Secure Diamond rating, Master Lock remains quite modest about the Mini U-Lock and its price is surprisingly low.

Naturally, the lock is on the smaller side for U-Locks, but we found that it’s still large enough to lock the rear wheel to your bike’s frame and go around a standard Sheffield Stand, securing your bike to an immovable object. On review we found that we needed to be a bit more careful about exactly what object we chose to 'lock up' to but this didn't present any real issues.

The plastic coating helps to avoid scratches to your bike and there's a dust cover over the lock mechanism to avoid contamination.  After several uses our bikes remained scratch-free. Be careful with your keys though; the four provided are all you'll ever have, as there's no key replacement service.

Finally, a bike mount would have been appreciated. During review we found ourselves popping out and having to bring a rucksack to carry the lock in, even though we didn't otherwise require the bag.

Read more: Master Lock Mini U-Lock full review

The Brute is Onguard's highest security lock, which locks the 16.8mm diameter shackle in four places, rather than the more standard two points of engagement. There's plenty of coverage with a flat area at the top of the lock rather than a curved one to increase space and the shackle is coated with thick rubber to help prevent frame damage.

The Brute has a high security locking cylinder, designed to prevent drilling or other assaults and with a rounded shape it helps prevent leverage around its edges. It comes with five keys, one with an LED to help you see what you're doing and unlock your bike after dark.

There are three different lengths of lock, so you can find one to balance portability and lockable area and the Brute comes with a frame mount. Despite its Sold Secure Diamond rating, the Onguard Brute is reasonably priced too.

Gram-for-gram, the Pitbull mini packs quite a punch. Despite only weighing 1.3kg it delivers a Diamond Sold Secure rating. It achieves this by measuring just 9cm x 14cm while still featuring a 14mm hardened steel shackle and a pick, pull and drill-resistant ‘bump lock’ cylinder. Its weight and dimensions makes it easily portable, either using the supplied mounting bracket or stuffed into a bag; 

I found it rattled less than a larger U-lock when mounted to the frame although it didn’t feel quite as solid as either of the folding locks. Naturally it’s size means the internal locking space is small, and will limit how and what you can lock your bike too - so perhaps not ideal for those who require some flexibility. 

However if you're locking your bike up to the same point each time, and know this compact lock fits, then it’s a great way of reducing your carrying weight without having to sacrifice the security rating.

Usually, the consequence of a lightweight and compact U-lock is a bit of a sacrifice in its usability, being too small to loop around objects and actually reach your bike.

But we found that simply isn’t the case with this lock. By the addition of a secondary shackle, the weight and size are kept low, but the total lockable area remains very respectable. Securing a wheel to the frame—in addition to reaching an immovable object—simply doesn’t present a struggle.

The main shackle even has a bent foot, which we found made it quite easy to mount the crossbar—exactly what you’d want in a lock designed around portability.

Regarding that portability, though, we felt that there is a significant omission. The lock doesn’t come provided with a bike mount and the mount available that is compatible with this lock is quite a cumbersome looking handlebar mounting option. For a lock that’s supposed to be used on the go, needing to bring some kind of bag to stow it in is quite an inconvenience.

It is also a little on the expensive side for its combination of security rating, weight, lockable area and portability. That said, if you do always have somewhere to keep the lock on your trips about town, you won’t be disappointed in its application.

Read more: Kryptonite Messenger Mini With U-Lock Extender full review

Best Chain Locks

Locks can act as an effective visual deterrent to bike thieves; by this measure the Kryptonite New York Fahgettaboudit chain is like a large, bad-tempered guard dog complete with foam at the mouth. 

Some 150cm in length, it’s made from a series of 14mm six-sided chain links made of 3t hardened manganese steel, all wrapped in a protective nylon cover. It’s locked using a padlock with 15mm steel shackle that benefits from a disc-style cylinder with both a reinforced anti-drill and anti-pull protection system. 

Unsurprisingly it’s heft is reflected on the scales, weighing almost 7kg. Ultimately it makes the chain far too heavy to carry around, unless perhaps you’re using it to lock up a cargo e-bike. However, its Diamond rating means it’s a good match for your home bike shed or garage, where it can be used to lock up an expensive road bike to a secured rack or mount.

Best folding locks

Folding locks bring a range of benefits over the venerable U-lock design. Not only do they tend to pack down smaller and have a larger lockable area, but their flexible nature greatly increases the range of objects you can lock your bike up to.

The typical downside of a folding lock is that with so many moving parts, they tend to be less secure than a simpler design, such as a U-lock. The hinge areas add a potential point of attack that's not there with  U-lock.

As such, the Abus is one of the only Gold rated folding locks currently available, but this superlative security does come with a couple of trade-offs. Tipping the scales at just under two kilos, the Abus lock is over four times as expensive and weighs just over half as much again as the Gold rated Zéfal K-Traz U17.

The Bordo Granit X Plus certainly isn’t all things to all people—but then, it isn’t trying to be. As a high security folding lock, it performs excellently. In addition to all the general benefits of folding locks, the Abus has a comprehensive rubber coating to protect your paintwork, a bike mount that is simple to set up and to use day-to-day, as well as an integrated weather seal on the lock barrel—adding some very welcome weather protection.

On review we found the bike mount not only straightforward to use but also capable of keeping the lock firmly in place, even when we were cycling on uneven and bumpy roads. Once we'd arrived at our destination the Bordo Granit X Plus' large lockable area made it easy to lock up our bike without any fuss; in fact we even locked up two town bikes using the one lock.

Read more: Abus Bordo Granit X Plus 6500 full review

As the name states, it’s a small folding lock. It comprises six steel bars, joined by stainless rivets, that add up to a circumference of 85cm; I found this internal locking space offers just enough room to secure the lock through the front wheel and frame before attaching to a bike rack or similar. Due to its smaller size it was less cumbersome and thus easier to use than the folding Abus - it’s as quick to lock up as U-lock but with a little added flexibility that’s inherent in the design. 

When folded away it measures just 18.9 x 6cm, which likely makes it one of the smallest and lightest Silver rated locks around. Again, like the larger Abus lock, it can be secured to your bike’s bottle cage mounts using a plastic case; similarly it feels secure and silent when in transit. If a combination of weight and portability is important to you then the Compact should have plenty of appeal.

Best Alarmed Locks

As the name would suggest, this Oxford lock comes with an inbuilt alarm that will sound if the internal motion sensors detect any tampering. It’s very simple to use, with arming and disarming controlled by just a turn of the key in the lock.

The calibration of the motion sensor was pretty spot on, detecting any suspicious fumbling, but not going off when the bike was just knocked a little when locking another up next to it. With the battery easy to access (when the lock is open), you can quite easily disable the alarm completely if you need it to work simply as a lock for any reason.

But this lock is by no means a novelty, it performs the basics really well. The bent shackle makes it easy to attach the crossbar, three keys are provided with more orderable, the bike mount is easy to set and works well in day-to-day use, plus its weight is pretty middle of the road for this style of lock.

The only reservation I have about this lock is that the rubber bumpers on the crossbar don’t extend all the way across, so some care is needed not to scratch your bike on the middle section of exposed metal.

Read more: Oxford Alarm-D Pro full review

The Abus 440 Alarm combines a robust hardened steel shackle with an in-built 100dB electronic alarm that's triggered by motion. It's an effective combination, although with only a Sold Secure Silver rating, the lock itself isn't as theftproof as the best. You can turn the alarm off for portage.

It operates using CR2 batteries. They're not that easy to source, so you might want to keep a stock in for when those supplied run flat.

There's a bike mount supplied that's easy to use, although finding a position for the lock within your frame might be an issue. The Abus 440 Alarm is heavy too, but in our review we said that: "This is much more than an 'opportunist anti-theft lock' option. If that is what you are looking for, you really can't go wrong with the Abus 440 Alarm".

Read more: Abus 440 Alarm full review

Best Lightweight Locks

The Z Lok weighs only 70g, so you’re not going to feel burdened by it if you stuff it into your pocket or clip it round your frame. The design is like an oversize zip tie and inside the plastic covering is a steel ribbon.

We reckon that if you use the Z Lok to secure your frame to a post or railing, it’s enough to stop a thief from walking away with your bike, although it’s unlikely to stand up long to a bolt cutter and its security level is unrated. Its steel band design is significantly more robust than other lightweight locking options, which tend to use thin cables, though.

At 40cm long, our reviewer found that there’s enough length to secure your frame to something immovable and possibly your rear wheel too. Because of its zip tie-like design, you can also shorten the loop to make it harder to get leverage with a cutter. There’s a release lever to undo the ratchet when unlocked.

In summary, we found that it’s a clever, useful bit of kit to carry around for the coffee stop or quick errands on the bike and cheaper than a full-strength lock too.

Read more: Hiplok Z Lok Combo bike lock full review

How we test and what to look for

How do Sold Secure test security and award ratings?

Sold Secure is an independent lock testing company based in the UK and its ratings are the industry standard for the security of bike locks. At the purpose-built laboratories in Rugby, locks are put through their paces against a variety of different attacks including—but not limited to—drilling, sawing, wedging and lock picking. 

Sold Secure is cagey about exactly how it tests, for obvious reasons, and it liaises with police forces to identify new attacks and incorporate them into its protocols.

Depending on how a lock performs in these tests, it is awarded a rating of Bronze, Silver, Gold, or Diamond. As a broad rule of thumb, Bronze is only deemed to be effective against opportunistic theft, Silver is good for bikes up to £1,000/$1,000 and Gold and Diamond are for bikes more valuable than £1,000/$1,000 and for particularly high crime areas.

How our bike locks are tested

We put the locks through the varied rigours of urban and utility cycling, using them for locking up outside work, the supermarket, pubs and running errands around town. 

In use, we consider aspects such as the weight, shape, locking mechanism, mounting attachment, tactile feel, security rating, price, and general user experience – essentially every quality of the lock, in real world situations. 

We don't try to cut through the locks ourselves – and there's a good reason for this. As we've mentioned in many places in this guide, no bike lock is ultimately unbreakable. The actual best way to protect the worth of your bike is through an insurance policy – and that will stipulate which level of security rating your bike lock should have.

Just to underline this point, it's the security ratings given by third-party testing companies, such as Sold Secure in the UK, that are important here.  Aside from the fact that these companies have professional testing protocols beyond what might be applied in a backyard test, insurers don't care about the results from anyone other than these companies. As they only use established third-party testers, their results are the only thing that's relevant here. 

For more details on how Cycling Weekly tests products, check out our How We Test page.

Typical insurer requirements

Not only will your insurer require you to use a certain level of lock, but you’ll also have to lock your bike in a particular fashion in order to be covered.

This isn’t to try and catch you out, it’s just there’s a very different level of risk depending on the way in which you’ve locked your bike up. We’ve all seen lonely front wheels securely locked to railings with the quick release undone and the rest of the bike long gone.

You’ll need to lock your bike through the frame – and preferably the rear wheel – to an immovable object. An additional cable may need to be used to secure the front wheel as well. This generally applies both to bike security at home and when locking the bike away from home.

Ultimate security

Sometimes the worth of a bike is measured in more than money – if your bike has sentimental value or is a model that can’t be replaced, an insurance payout is not going to cover what was lost. In this case, prevention is much, much better than any ‘cure’.

For the ultimately secure set up, you should use two Diamond rated locks and use them to lock each wheel to the frame and through to an immovable object. When locking each wheel, make sure to go around the rim rather than just through the spokes – these can be cut and replaced very easily.

You’ll want to be sure that the object you’re locking to is genuinely immovable, being at least equally as secure as the locks. Depending on your garage setup, you may need to purchase a ground anchor to ensure this is the case when your bike is parked at home. Check out our piece on bike security at home for more.

Also, don’t overlook the security of the place you are locking your bikes, you may need to upgrade the locks to your garage, for example. But equally, don’t go overboard. Five sets of locks on a door and three security cameras are only going to intrigue a thief. Discrete but high security is the best combination.

This is well in excess of what any insurer would ask you to do. If you would be satisfied with an insurance payout should your bike be stolen (provided it was locked to the insurers’ standards), then this level of security is completely unnecessary. But if your bike is genuinely irreplaceable, these are the step to take.

For a cheap and simple, pared down town bike, you could get away with using a small Silver rated lock and some lockable quick release skewers to keep the wheels safe. This is a lighter and simpler solution than the lock and cable method preferred by insurers, but as a consequence, you may not be covered locking your bike up in this way.

Either double check with your insurer that they will cover you locking your bike in this way, or make sure your bike is cheap enough that if it does get stolen an insurance claim wouldn’t be worth it anyway.

D- / U-locks

D- / U-locks with their simple and robust design lend themselves to high security applications, although with a consequential high weight. But the same elements which make U-locks an easier design to make high security, also means that mid-level security can be offered at a sometimes surprisingly low weight. This versatility is why the U-lock design is so popular for bike locks.

Folding locks

Folding locks bring a different set of benefits. Not only does their design allow folding locks to pack down smaller for easier transportation, but they also tend to come with a larger lockable area and their flexible nature greatly increases the range of objects you can lock your bike up to. The typical downside of a folding lock is that with so many hinging parts, they tend to be less secure than a simpler design - the rivets are an easy target and it's quite easy to apply leverage between the links.

Chain locks

Chains go some way to merge the benefits of folding locks and U-locks, tending to have a similar security level to U-locks but being flexible like a folding lock. The downside mainly centres around the weight, which is often considerable (over 3kg) and therefore limits them to use only at home.

Having said that, there are options like Hiplok's range that are designed to be carried, it's just that the lock may be a bit weighty. Most chains come with a fabric covering too, so they shouldn't damage your bike when in use.

But for securing multiple bikes, using a couple of U-locks is much safer than a single chain – and with Gold rated options such as the Zéfal K-Traz U17, the total price and weight will probably even be similar.

Lightweight locks

Lightweight locks tend to use a cable design. These are pretty vulnerable to cutting attacks, but are effective against opportunistic thieves without specialist tools. These are good for providing a bit of extra security at a café stop, so someone can’t just sneak off with your bike while you’re looking in the wrong direction.

However, they aren’t robust enough to use in high crime areas when you are leaving your bike for any length of time, and your insurance probably won’t cover you if your bike is stolen while locked up with one.

For extra security you can combine a lightweight lock with a bike alarm like the Alterlock, which sounds a siren if your bike is moved.

Many home insurance policies will only cover bikes up to £1,000/$1,000, so if your bike is worth more than that, you really should take out some specific bike insurance. These policies also tend to include other benefits such as public liability and personal accident cover, so are well worth the investment.

Different insurers will have different requirements, so make sure to check the policy wording of your own insurance, but typically, if a bike is worth over £1,000 it will need to be locked using a Sold Secure Gold rated lock. If the bike is worth under £1,000/$1,000, it will need to be locked with a Silver rated lock. Few insurers will cover a bike locked with a bronze or unrated lock.

Should I fit a bike tracker? 

I would say, Yes! Bike trackers are a great way to retrieve your stolen bike but also just to check it is still where you left it. There is a whole host of trackers out on the market that offer a variety of services. From just a dot on a map like Apples Airtags to subscription based services, that will recovery or replace your bike. 

It is worth noting that you should never go after a thief yourself. If your bike is stolen, report it to the police and allow them to do their job. Bike trackers provide the police with the information they need to act swiftly.