Bike lock purchasing advice: how to choose the right product

  • What you need to know
  • No bicycle lock offers one hundred percent protection against theft, but high-quality models increase the security of your bike enormously.
  • To make it particularly difficult for thieves, secure your bike with two different types of locks.
  • When choosing a bicycle lock, it is important to weigh up security and convenience.
  • High-quality U-locks offer the best theft protection, but they are very heavy and bulky.
  • Folding and chain locks are a good compromise between security and flexibility. Frame and cable locks are not recommended as sole theft protection.

Making life difficult for thieves

Bicycles are an environmentally friendly and at the same time healthy means of transport. Unfortunately, the two-wheeled means of transport is also popular with thieves. According to a study by the bicycle registration service 529 Garage, bike thefts have doubled in the last 20 years and over 2 million bikes are stolen each year in North America. Since not all thefts are reported to the police, the number of unreported cases is probably significantly higher. Thus, if you don’t want to lose your new bike right away, you should invest in a good bike lock.

Deterrence and gain time

No bicycle lock offers one hundred percent theft protection. With enough time and the right tools, even the most robust lock can be cracked. Nevertheless, high-quality models significantly increase the security of the bicycle. On the one hand, good bicycle locks already deter thieves and make it as difficult as possible for them to steal the bike. The longer it takes to pick or cut the lock, the higher the risk of being caught in the act. That’s why it is recommended that a bicycle lock should withstand violent attempts to break it for at least three minutes.

Bicycle locks for different purposes

Bicycle locks can be divided into five different types according to their design. While high-quality U-locks, chain locks, and folding locks offer a high level of security, frame locks are not sufficient as sole protection, but are at best suitable as additional protection together with another lock type.

U-lock: maximum security

U-locks, also called D-locks, are the most secure type of lock, according to experts. They consist of two parts: a large, U-shaped metal shackle and a straight locking bolt into which the shackle is inserted. The two components are immovable and made of hardened steel, which makes them particularly robust and difficult to cut. The thicker the shackle, the more difficult it is to crack open.

However, high-quality U-locks weighing around 3 to 6.5 pounds are quite heavy, bulky, and unwieldy. Transporting them over long distances is correspondingly tedious. Bike owners therefore have to weigh up convenience against security. For example, a heavy U-lock is not absolutely necessary for long bike rides where the bike is parked briefly within sight. On the other hand, it offers a high level of theft protection for long-term locking at the front door or in the basement, where there is a risk of burglary. Note that the shackle is inflexible, which makes it difficult to choose a suitable connection option. For example, many models are too small to use to connect the bike to a thick lamppost or a tree.

U-lock in use
U-locks are very secure but not very flexible.

Chain lock: the flexible alternative

Chain locks consist of solid steel links that are usually coated with plastic or nylon to protect against rust. The thicker the chain links, the more security the locks offer. While thin chains with diameters of five or six millimeters can be cut through with bolt cutters within a few seconds, thick chain locks offer similarly reliable theft protection as U-locks. However, weighing up to 10 pounds, they are even heavier than many U-locks.

The big advantage of a chain over a U-lock is flexibility. Longer chain locks, for example, can be easily threaded through the bicycle frame as well as the front wheel and placed around a lamppost or used to lock several bicycles. In addition, you can fold the chain compactly for transport.

locked chain lock
Chain locks are moderately secure and flexible.

Folding lock: handy and secure

So-called folding locks consist of several parts made of hardened steel and connected by joints. This means they can be folded up and stowed in an included holder on the bike. They weigh between 1.5 and 4.5 pounds, less than many U-locks. Thanks to sturdy, fairly wide links and joints, high-quality folding locks are difficult to pick. This is a good compromise between security and convenience.

Folding locks are less bulky than U-locks, but not quite as flexible as chain or cable locks. However, with sufficiently long models, you can connect your bike well to wider objects. Folding locks, for example, are a good solution for commuting. You can conveniently carry the lock on your bike and lock your bike comparatively securely on site.

floding lock in use
Folding locks are practical and secure.

Cable lock: flexible and lightweight

Simple cable locks consist of twisted steel cables with a rubber coating. They are flexible and lightweight, but also easy to break — a pair of side cutters can cut through them in a matter of seconds. Such models are sufficient, for example, to provide additional security for an old bicycle or another lock, or to lock the bicycle just before going to the bakery to fetch bread. However, they are unsuitable as sole, long-term theft protection. Armored cable locks, whose steel cables are sheathed in steel sleeves, offer greater security. They are much more difficult to cut than simple cable locks. Compared to high-quality U-locks, chain locks, or folding locks, they are nevertheless easier to pick.

The advantage of cable locks is their convenient handling. With sufficient length, you can easily connect your bike to wider objects such as lampposts. With some models, you can also secure two bikes together. In addition, cable locks are less heavy to transport than heavy U-locks.

cable lock in use
While flexible, cable locks are easily cut.

Frame lock: a secondary lock

Frame locks are integrated directly into the bicycle frame and are installed on many bikes as basic protection. They are located on the rear wheel, which is blocked by a metal pin between the spokes when locked. Inexpensive models are made of plastic, higher quality ones are made of steel. Frame locks are very convenient because they only need to be closed and not put around the wheel every time. In addition, they are the lightest and cheapest lock version, albeit the least secure.

locked frame lock
Frame locks do not offer much security.
Why is a frame lock not recommended?

Frame locks are not sufficient as the sole theft protection. You can’t use them to lock your bike to firmly anchored objects. Instead, locks only block one wheel and are more of an immobilizer. By lifting the secured rear wheel, the bike can be easily pushed away despite the frame lock. In addition, inexpensive models made of plastic are very easy to crack. In some cases, it is sufficient to lift the locked wheel and let it fall to the ground. You should only use the frame lock as the sole safeguard when you park your bike briefly in sight. It is better suited as additional theft protection to a safer lock. For example, the manufacturer Abus offers combinations of frame and chain locks.

The different types of bicycle locks at a glance

The following overview shows the most important features of the different lock types:

Lock typeU-lockChain lockFolding lockCable lockFrame lock
Theft protectionVery highHighHighLowVery low
Weight3–6.5 lb1.5–10 lb1.5–4.5 lb0.5–2 lb1–2.0 lb
Example modelsAbus Granit Xplus, Trelock BS 450Kryptonite New York Chain, Abus Granit XplusAbus Bordo Granit XPlus, Trelock FS 460Abus Citychain, On-Guard BeastAbus Amparo, AXA Defender
A comparison of the five lock types.

What locking options are there?

Regardless of the type of lock, there are various locking mechanisms. The classic is the lock cylinder with a key. If you don’t want to carry a key with you, a combination lock is a good alternative. Depending on the model, you have to remember a three- to five-digit code to open the lock. Some models can even be operated via an app on your smartphone.

We will look at the advantages and disadvantages of the three locking options below:

cylinder lock

Cylinder lock

Cylinder locks, especially models with disc cylinders, are very secure. As long as you have your key with you, the lock can hardly be opened without force. Lock picking with special tools is hardly ever done in practice. Furthermore, cylinder locks are easy to lock and unlock with the key. High-quality models have an LED light in the key, which makes it easier to unlock in the dark. However, there is always the risk of misplacing or losing the key. It can also bend or break off in the lock.

combination lock

Combination lock

The following applies to combination locks: the more digits there are, the more difficult it is to guess the code. A three-digit lock is not recommended, four- and five-digit models are safer. The advantage over the cylinder lock is that there is no key that you can misplace or lose. On the other hand, there is the risk of forgetting the combination code or being spied on when setting the combination. When choosing a combination lock, make sure that you can change the combination.

app bike lock

App bike lock

Electronic bicycle locks that are controlled by smartphone are particularly convenient. You need neither a key nor a combination of numbers. Depending on the model, the lock even closes automatically as soon as you move away from the bike and alerts you via app in case of an attempted break-in. However, you have to charge the battery of the lock regularly. In addition, smart bike locks have the disadvantage that they are even more expensive and less secure than the alternatives. Most of them are frame locks. In addition, the connection between the lock and the smartphone poses a new security risk.

Opening an app lock when the battery is flat?

App locks may be particularly convenient, but the question remains how the lock can be opened when its battery is flat. So far, the smart models do not offer any kind of emergency key. Instead, they warn their owners when the battery is low. If the battery runs out before they can open the lock, users have to supply it with power via a power bank or open it by force.

How do I find the right bicycle lock?

Even within the different types of locks, the models sometimes differ greatly from each other. In addition to the locking mechanism, the material, which also determines the weight, is decisive for the security offered by the lock. Test seals and the manufacturers’ security levels provide orientation. Depending on what you want to connect your bike to, the total length of the lock also plays a role. In addition, some models are equipped with an acoustic alarm.


Bicycle locks made of hardened steel are particularly robust and unyielding. Ideally, the lock is made entirely of this material. This is the case with most U-locks and high-quality folding and chain locks. Especially with heavy chain locks, you should look for a cushioning textile or plastic casing. This protects the paintwork of your bike from scratches when the heavy chain hits it during connection. Cable locks are also usually sheathed. They are made of steel cables that are comparatively easy to cut. In the case of so-called armoured cable locks, a steel casing provides additional protection.


Hardened steel is not a light material, and the thicker the lock components, the harder they are to cut. A secure lock therefore weighs a lot. Robust chain locks are particularly heavy at up to 10 pounds, closely followed by U-locks at up to 6.0 pounds. Folding locks are somewhat lighter: heavy ones weigh about 4.5 pounds. With all three lock types, you should choose a model weighing at least 3.5 pounds to be on the safe side. If you are looking for a particularly light lock, you will find it in cable and frame locks. Both are available with weights of less than 1 pound. However, such lightweight locks are only suitable as a secondary lock for additional security or for short-term locking within sight.

Security label

Locks that look robust and secure are not always difficult to pick. Information about the security of the various models is provided by seals from independent testing institutions. Reliable proof of quality includes the Sold Secure and ART foundation. Locks with these certifications have been tested according to the DIN EN 15496 standard. Depending on the type of lock, the tests include sawing, drilling, and cutting with various special tools as well as targeted attacks on the lock cylinder. In addition, the bicycle locks must pass the freezer test in order to receive a label. In this test, the entire lock is cooled down to -4 °F and then attacked with a hammer and chisel.

Sold Secure – UK’s premier testing and certification house

Sold Secure is an institution from the UK that tests security products. Manufacturers can apply to have their products tested and then may be awarded the Sold Secure Approved quality mark. For a better overview, approved products are subdivided into four levels of theft resistance:

  • Bronze – secure against basic tools
  • Silver – secure against enhanced tools
  • Gold – secure against dedicated tools
  • Diamond – secure against specialist tools

ART foundation – bike security from a country of bike enthusiats

The ART foundation is based in a country where the bike is the most important means of transportation: the Netherlands. The foundation is specialized in theft prevention of two wheelers (bicycles, mopeds, and motorcycles) and has established a quality mark system. The rating is expressed is stars, one star being the minimum security level to get an approval and five stars being the most secure.

Security class

In addition to seals of approval from independent test institutes, various security classes from some suppliers provide information about the theft protection of a bicycle lock. It should be noted that the manufacturers set their own security levels. They are therefore suitable for comparing locks from the same manufacturer, but not models from different companies. Abus and AXA, for example, divide their locks into 15 security levels, while Kryptonite has ten and Trelock only six.

Handling and dimensions

The longer a lock is, the easier it is to lock your bike to fixed objects. However, more length also means more contact surface for thieves to break it as well as more weight. Cable locks with lengths of up to 100 inches offer the greatest range. This makes them ideal for locking several bikes together. With the heavier chain and folding locks, manufacturers pay more attention to weight reduction, which is why the range is usually limited to 27 to 40 inches. U-locks have the lowest range of 8 to 30 inches. They are poorly suited for locking several bicycles together and only to a limited extent for connecting to objects. The frame lock, which only serves as an immobilizer, has no range at all.

Acoustic alarm

Smart bicycle locks that can be connected to a smartphone via Bluetooth are usually equipped with an alarm function. However, there are now also cylinder and combination locks with this additional feature, such as the folding lock Abus Bordo Alarm 6000 A. Bicycle locks with an acoustic alarm are usually battery-operated and activate themselves automatically when the lock is closed. If someone tries to tamper with the lock, a loud signal sounds to deter thieves and attract the attention of passers-by.

How much does a secure bicycle lock cost?

Inexpensive frame and cable locks are available for prices below $10. However, experts advise against saving money a lock. The prices of good folding locks, U-locks and chain locks, start at around $50. This is also the minimum value that many bicycle insurance companies set as a prerequisite for covering a bicycle theft. It’s advisable to look at the price of the bicycle when buying a bicycle lock: consumers should plan five to ten percent of the bike price for the lock purchase. However, this rule of thumb can hardly be implemented for very high-priced bicycles. For such models, it is advisable to secure them with another type of lock.

Security classes

The best-known bicycle lock manufacturers include Abus, AXA, Kryptonite, and Trelock. They divide their bicycle locks into specially defined security classes.

Abus – 15 security levels

Abus divides its bicycle locks into 15 security classes according to cylinder technology, shackle or chain strength, and ease of use:

Theft protectionBasicMediumMaximum
Recommended theft riskLow Low to mediumHigh
Recommended bike valueLowMedium High
Example modelAbus RACER 660 SHADOWAbus Ugrip Bordo 570/80CAbus Bordo Granit XPlus 6500/85
The 15 security levels of the manufacturer Abus.

AXA – 15 security levels

As with Abus, AXA offers 15 security levels for bicycle locks and even 25 for motorbikes. The security classes here are called ‘Safety Index’ and evaluate the break-in security.

Safety Index1–67–910–15
Theft protection Basic securityMedium securityHigh security
Recommended useFor low theft riskAs a secondary lockFor expensive bicycles
Example model AXA Newton cable lockAXA Toucan folding lockAXA Linq Chain lock
The 15 security levels of the manufacturer AXA.

Kryptonite – 10 security levels

At Kryptonite, bike locks come in ten security levels, with a 1 being a deterrent and a 10 being the ultimate security level:

Security level1–34–67–89–10
Theft protectionLowLow to mediumMedium to highHigh
Suitable parking locationRural areaSuburbs/
metropolitan area
College campusMajor metropolitan area
Suitable timeShortShortAll dayOvernight
Example modelKryptonite Kryptoflex 1265 cable lockKryptonite Keeper 510 folding lockKryptonite Evolution Serie 4 StandardKryptonite New York Lock Standard
The 10 security levels of the manufacturer Kryptonite.

Trelock – 6 security levels

The manufacturer Trelock divides its bicycle locks into ‘security levels’ 1 to 6. While models with level 1 are only suitable as additional security for short stops, locks with level 6 also offer reliable theft protection at night.

Security level1–23–45–6
Theft protectionBasic securityMedium securityHigh security
Recommended useAdditional securityAdditional and main securityAdditional and main security
Recommended parking durationQuick stopsDuring the dayDuring day and night
Recommended bicycle valueMid-value bikesMid- to high-value bikesHigh-value bikes and e-bikes
Example modelAXA Newton cable lockAXA Toucan folding lockAXA Linq chain lock
The 6 security levels of the manufacturer Trelock.

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