Not all bike locks are created equal and here at Sundays, we think your bike deserves the best lock possible. Specific traits and features increase a bike lock’s level of security and its ability to effectively prevent bike theft.
In this article, I’ll explain what differentiates high-security bike locks from weaker locks and what to look for during your search for the ultimate bike lock.
Types of bike locks
Higher-security locks are typically bulkier than low-security models due to thicker metal and heavy-duty locking mechanisms. D-locks (also called U-locks), chain locks, and premium frame locks offer the highest levels of protection. Cable locks and thinner D-locks provide a medium level of security for your bike. Lastly, small café locks and wheel locks are convenient, secondary locks rated at the bottom end of the security spectrum. Standard padlocks aren’t used for bike-specific locks— instead, bike locks feature more robust and weather-proof locking mechanisms.
Security ratings
Bike lock brands like ABUS and Kryptonite use a numerical scale to rate the security levels of their products. This simple numbering system helps riders compare different locks at a glance. ABUS’ scale ranges from very basic (1) to ultimate security (15) while Kryptonite uses a 1-10 system. These relative ratings aren’t absolute security guarantees but are useful when picking out the right lock for your needs. Bike lock prices typically increase the higher they place on the brand’s security rankings. Check out the comprehensive chart below provided by Kryptonite:
Sold Secure rating
You’ll likely notice a Sold Secure rating when browsing quality bike locks. There are four levels of bike lock security in this rating system: Bronze, Silver, Gold, and Diamond. But what is Sold Secure and what do the ratings mean?
Sold Secure is an independent nonprofit based in the UK that thoroughly tests security products. Manufacturers can apply to have their products assessed by Sold Secure at its facility and only the products that pass these tests can carry the coveted Sold Secure Approved quality mark. This way, consumers can have a trusted third-party opinion about the quality of a bike lock instead of simply believing a brand’s own claims or rating system.
The Sold Secure organization is hugely helpful to cyclists for a variety of reasons. Firstly, the rating system is standardized which allows us to reliably compare different locks from several brands. As an independent testing organization, Sold Secure classifies the widest range of locks that covers most of the top products on the market. Sold Secure also constantly updates its testing methods and ratings to keep its recommendations as current as possible. Many bike insurance policies even specify that riders must use a Sold Secure-rated lock to meet coverage requirements.
Riders looking for a bike lock can browse Sold Secure’s comprehensive catalog of approved & rated bicycle security products. You can even narrow down your search based on the type of bike lock you need.
Sold Secure Grading Levels
Sold Secure classifies products into four levels of theft resistance. These tiered ratings are based on a bike lock’s resistance to certain types of attacks, different tools a thief may use, and the time required to break the lock. Below is Sold Secure’s description of each of the security levels:
Sold Secure Bronze: Offering theft resistance against a basic tool list (aimed at preventing opportunist crime)
Sold Secure Silver: Offering theft resistance against an enhanced tool list (aimed at preventing more determined attacks)
Sold Secure Gold: Offering theft resistance against a dedicated tool list (aimed at preventing dedicated attacks)
Sold Secure Diamond: The highest level of theft resistance including the use of specialist tools (aimed at preventing the most destructive attacks that could include angle grinders)
Insurance and warranty eligibility
Using a high-security bike lock can also come with insurance and warranty benefits in the unfortunate event of bike theft. As mentioned, even the best bike locks can be broken with the right tools and sufficient time, so theft can still occur. Still, the best lock manufacturers and brands stand behind the quality of their security products and may offer additional guarantees.
For example, Kryptonite provides an Anti-Theft Protection Offer (APTO) on specific locks which reimburses registered customers for a specific monetary amount in the event of theft. Assuming the bike lock was used correctly, Kryptonite will compensate you the base cost of your bicycle (excluding accessories) or any insurance deductible, whichever is the lesser amount. The table below outlines the maximum amount users are covered for based on the type of Kryptonite lock they have:
Many bicycle insurance policies also specify that you must use an approved bike lock to be eligible for maximum coverage in case of theft. Following your insurer’s bike lock requirements will facilitate any future claims or compensation. Using a high-quality bike lock is a good idea anyway as it lowers risk for both you and your bike insurance provider. Let’s face it, no one likes bike theft! Sundays Insurance maintains an updated list of approved bike locks, including keyed D-locks, folding locks, and chain locks.
Security vs. convenience
Bicycle locks must be, first and foremost, highly secure— but the best products are also convenient and easy to use. The right bike lock for you must match your security needs and riding preferences. For example, super heavy-duty locks that are awkward to carry aren’t worth the splurge if you find yourself reaching for your flimsy cable lock instead.
In my book, the best bike lock is the one you’ll actually use! While this statement has its limits of course (it has to be secure enough), it’s important to remember that one of the qualifications of being a secure bike lock is that the lock is used frequently. Having an ultra-thick chain that’s too heavy and cumbersome to bring along on a ride won’t do you any good if you don’t have it with you while out for a café stop.
Keeping your bike safe in the city isn’t only about having the right bike lock. Make sure you lock up your bike appropriately and use additional security accessories to reduce the chances of getting your bike or any of its parts stolen.
Watch this video from GCN to learn about the most effective urban bike security tips!
Usability and design
Bike lock manufacturers attempt to solve the dilemma between security and convenience with intelligent lock designs. Products like lock mounts on your frame, foldable locks, and wearable locks are convenient ways to ride with heavy-duty bike locks without sacrificing comfort. That said, it’s a matter of fact that high-security bike locks are very heavy. Secure locks are made of thick metal with complex tamper-proof locking mechanisms that are there for a reason, not just to weigh down your bag— I promise.
There are certain desirable features that can boost a bike lock’s security and overall usability. Many D-locks only lock on one side which can make them prone to prying open and quicker theft. The most secure models, however, have dual-side locking so thieves have to spend double the time when attempting to fully release the lock. You can also choose between combination locks or key-operated locks depending on your preferences, but the highest security locks are typically keyed. Lastly, it’s important to check that your metal lock has an outer material that will prevent it from scratching your bike’s frame. Chain locks normally have a durable fabric covering while D-locks come with a rubberized finish.
Bike lock carrying tips
I recommend against using only a thin, lightweight cable lock to secure your bike. An approved D-shape, folding, or chain lock will keep your precious bike much safer while out in the open. If you find yourself inconvenienced by the bulk of bike locks or their notorious habit of rattling around, there are a few solutions. Many models come with a frame mount to attach the lock to your bike rather than carrying it on your person. Folding locks can also help save space and avoid the awkward shape of other locks. Bike messengers often carry their D-locks on a hip pouch or tucked into their belt to move the extra weight from their back to their waist instead. I’ve been a convert ever since I learned about this trick— those experienced riders know a thing or two!
The most secure bike locks make it extremely difficult for a potential thief to successfully break the lock, requiring special tools and a prolonged attack on the lock. ABUS’ highest security rating is between 10-15 while Krptonite’s scale maxes out at 10. A Diamond-level rating marks Sold Secure’s highest mark of approval.
D-locks, also referred to as U-locks, are commonly regarded as the most secure type of bike lock. Folding locks and chain locks can also provide a very high level of theft protection. The most important factors in the strength of a bike lock include the quality of the material, lock thickness, and anti-tamper mechanisms within the lock.
A Sold Secure rating means that the bike lock is a quality product approved by Sold Secure, an independent and non-profit tester of bicycle and motorcycle locks. To achieve a rating, locks have to achieve a certain standard of security and are given Bronze, Silver, Gold, and Diamond-level ratings according to their specific level of theft protection.
Money spent on bike security is money well spent to protect your investment from tampering and theft. Some cyclists recommend budgeting to spend around 10% of your bike’s overall value on security accessories like a bike lock. Spending at least $50 will allow you to buy a quality bike lock that will protect your bike and there are plenty of more expensive options for added security.
Finding the best bike lock for you will depend on your specific security needs and preferences. At Sundays, we require bike owners with our coverage to use an approved lock— each of the approved locks receives a high-security rating from their manufacturer or the independent tester Sold Secure. Using a non-approved lock will lead to an unsuccessful claim in the event of bike theft. If your bike lock is not on the list of approved locks, Sundays will need to review the product.
Standard padlocks, or portable locks with a U-shaped shackle, are not recommended for securing your bike. Household padlocks are less secure than bike-specific locks and aren’t designed for daily riding and exposure to the elements either. A heavy-duty padlock and thick metal chain may effectively secure your bike at home or in a shed, but cyclists on the move should use a bike-specific lock.
