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The Best U Locks for 2023

best u lock

There are different types of bike lock mechanisms available in the market today. So, it is all up to the bike owner to choose his preference for protecting his bike. One of these options is to select the best U lock for bikes in preventing outside threats coming from criminals. U locks are stiff metal rings in the shape of the letter U and are usually attaches to the crossbar section of the bike.

In the U.K., bikers called it the D-locks, but in the bikers community, U locks are considered one of the most secure locking mechanisms due to their resistance to cutting with those powerful hand tools such as the bolt cutters. For this reason, we are reviewing ten of the best bicycle U locks today. This review includes buying guide and other related information to help all bikers select the best bike U locks for their bikes.

Best U Lock Reviews

1. Via Velo Bike U Locks

via velo bike u locks

When looking for a perfect U lock for your bikes, there are a lot of factors to consider. But, ultimately, it all boils down to the type of security it can give to your bicycle. With Viva Velo U bike lock, it combines the security and safety that the U lock gives and the versatility and flexibility of a cable lock. This product is one of the good U locks for bikes available today and is well-known in the biker community.

I have heard this U lock brand from a friend who was very vocal about his experience with the product. I was curious and did get one to test its quality and reliability to my bike, and I was impressed with what I saw. Physically, I was impressed with its physical features, especially the thickness and the size of the shackle. If you add the length of the cable, locking the bike was was fast and easy with this locking mechanism.

Honestly, no bike lock cannot be broken with an experienced theft using the right tools. But the nest best thing to do is to have a security system for your bike that will make it hard for all those outside threats to successfully doing their criminal acts. However, using this lock will let you wrapped around the rack, then through the frame and the rear wheel. The cable will then go through the front wheel, making it hard for the theft to cut it through,

Physically, the U bolt looks solid and robust while the locking mechanism engages both ends of the bolt. I feel that the cable’s size and length are enough to withstand the threats of big bolt cutters. The U lock is also covered with a hexagonal PVC cover which provides corrosion resistance from water, dust, and other external threats. This feature will give additional durability and adds the life span of the product.

Another thing that I like when having this product is getting two keys in the package. These two keys will bring convenience and security, especially if your lost one unintentionally. You can use one key for your daily use, and the other will be your spare or reserve and should be kept in a safe but accessible place.

  • Includes a mounting bracket to provide comfort when carrying the lock
  • Solid and durable bike lock
  • Provides all-weather resistance feature
  • Great thickness and size to provide maximum security
  • Locking the bike is easy, fast, and quick
  • Bike mount will take a lot of space

This product is for bike owners looking for security and strength in a bike lock. Add the other features of this lock, especially the added cable attachment, and you will get maximum security and safety for your bicycle.

2. UBULLOX Bike U Locks

ubullox bike u locks

The Ubullox bike U lock is one of the best U bike locks and well-known bike locking systems available today. It is made with high-quality materials to withstand human and environmental threats and give your bike the maximum protection it needs. It is a 2 in 1 bike lock that combines the U lock’s durability and the versatility of the cable lock that will give you a sense of security when leaving the bike alone.

Comparing it with the Via Velo U bike lock, they share few similarities, including the design and the style. Both contain the U lock, cable, and mounting bracket in their locking system, but that’s the only similarities they share. The Ubullox is a lot smaller, more portable, and it comes with three copper-coated keys. Meanwhile, the lock cylinder with a pure copper blade provides resistance to any cutting or breaking attempts.

In my opinion, this is an excellent lock set to have, although it is a little bit smaller compared to other locks that I used previously. The upside of the smaller size is it can be stored easily on the bike, weighs lesser, and can provide the same effectiveness as the large ones. I also like the storage mount, which is easy to install and lets you mount it in the direction of your preference. And the best thing is, the bracket will fit and mix nicely into the bike.

Physically, it is a solid lock and is much thicker compared to the other U locks. Also, the shackle is well-built and is covered with soft rubberized materials. The advantage of having this thing is that it prevents the lock from scratching the bike frame’s surface. It will also help make the ride quietly with the mount unable to produce unnecessary sounds because of the rubber.

Overall, this lock is what the bike owners need to secure the bike when doing quick-stops such as going to the grocery stores, stopping for lunch, and other similar activities. The locking mechanisms work smoothly, while the mounting bracket is well-designed. The only issue I see is the size of the U lock, which will sometimes prevent you from locking the frame and tire together without using the cable.

  • Made with alloy steel to provide durability and toughness
  • Lock cylinder made with a copper blade to provide technical opening resistance
  • Steel cable provides flexibility and additional protection
  • With easy to install mount bracket holder
  • Provides portability feature
  • U lock is small may not fit large bike frames and racks

This small U lock is for bike owners looking for both portability and security in a bike lock. This locking mechanism is easy to bring with and does not weigh too much, which means more comfort and convenience to the biker. It also gives the same maximum protection and safety to your precious investment.

3. Bell Catalyst Bicycles U-Locks

bell catalyst bicycles u-locks

There are many reasons why U-locks has the highest security ratings of all the different type of locks. But it all depends on how you plan to place the right security system with your bicycle. In connection with the statement above, this Bell Catalyst U-lock is one of the best in the industry in keeping your bike securely from outside threats. It comes in different sizes but should provide the same type of protection to your bike.

When talking about the benefits of this product, there are many to mention. For one, this is a sturdy lock that will give protection to your bike when being left outside and unattended. Thanks to its 8-inch hardened steel shackle and a sturdy crossbar, which provides the most challenging security in your bike. The lock is more secure than other regular locks, mainly if used on the bike frame.

Apart from being a heavy-duty lock, one upside from using this product is the added protection you will get after the purchase. The anti-theft protection program will cover you if the unusual thing will happen if the theft succeeds in breaking the lock and steal the bike. That will give you additional comfort and peace once you decided to have this bike lock. Also, I like the quality of the key, which looks like a car key with intense light.

If you are always parking in an area where there is always a high volume of people and the threat of stealing the bike is high, this bike lock is a must for you. It will be the best protection you can give to your bike and prevent it from being stolen. For sure, there are plenty of bike locks you can choose from, but I highly recommend this one.

The only drawback I see this product is the difficulty in the opening, especially if you are using it for the first time. Turning the key and opening it will be difficult, and it will not be smooth. It is up to you to find out and learn the right strategy to open the lock.

  • Provides the most rigid security with its strong crossbar and steel shackle
  • With anti-scratch protection
  • Heavy-duty and high-quality construction
  • With anti-theft protection program
  • ‘Comes with a unique pair of keys
  • Difficulty in locking and unlocking with the keys

If you live in a place where the probability of your bike being stolen is high, I suggest owning this locking mechanism from Bell. This product is one of the best bike locks that I have used, and I recommend this due to its quality and reliability.

4. Kryptonite Evolution U-Locks

kryptonite evolution u-locks

In the biking industry, Kryptonite U lock is synonymous with maximum security of your bike. As a company, they have trusted experts in manufacturing premium products for bicycle protection and security. Kryptonite is one of the more popular brands and is known for producing high-quality bike locks. In connection with this, the Kryptonite Evolution U lock provides the brand’s quality and is considered the lightest weight U lock option in its line.

In terms of its quality, this current version of the Kryptonite U lock looks legit. I was impressed the first time I checked it because the keys and the locking mechanisms were adequately lubricated. It operates smoothly the very first time I inserted the key. The mounting hardware was also easy to install on the bike. It allows multiple positions and directions depending on your preference.

This high-security lock provides an excellent fit for its size and is large enough to lock your bike on parked meters, bike racks, and even street signposts. Although, the size is too small if you want to lock it around the bike’s frame or the wheels. Although, you can always use a cable if you plan to do this way of locking your bike. This bike best fits when you are doing quick-stops for grocery, going to a public restroom, among other similar activities.

Physically, this bike lock is heavy-duty and solid. In my opinion, this is one of the strongest and durable locks you can use for the security of your bike. The bike loop cable’s length is enough to fit and wrap around both wheels and the U lock. I suggest that you figure out a way to find a process that will properly secure your bike given the length of the cable and the size of the U lock.

The biggest downside of using this version of U lock from Kryptonite is that the size is too small that it limits your capability in securing your bicycle. Yes, you can always use the cable, but it will decrease the level of security towards your bike.

  • Hardened steel shackle resists attacks from different hand tools
  • Kryptonite’s lightest weight U lock
  • It comes with three stainless steel keys, including a LED powered key fob
  • High-security cylinder provides pick and drill resistance
  • Offers key-safe program and anti-theft protection
  • U lock’s size is too small
  • The bike mount is noisy during the ride

The Kryptonite Evolution U lock is for bikers looking for a portable and light U lock for their bike. It offers the same protection as the other previous Kryptonite U lock but is smaller and is easy to carry.

5. SIGTUNA Bike U locks

sigtuna bike u locks

Big and strong: these are the two words which best describe this best U bolt bike lock. A premium, high-quality lock that provides maximum protection to your bike is what you need, and this is what this U lock from Sigtuna offers. Made with solid and robust materials, this bike lock will frustrate thieves from breaking and cutting it, thus preventing your bike from being stolen.

One of the outstanding features of this product is its durability and strength. The U lock is sized at 16 mm and is made with high-performance steel, which provides durability, power, and resistance against attacks from thefts. Meanwhile, the cylinder comes with a double-locking mechanism that prevents the theft from picking the lock. I feel that will all these security features; your bike will be safe when being left alone.

Although the lock is heavy, the 16 mm steel will give you the best security even with the extra weight. It can be hung on the top tube of your bike, and it will hold well. The plastic covering of the cylinder is well-built and should protect the surface of your bike from scratching. Meanwhile, the mounting bracket will give versatility in terms of positioning in different directions. All you have to do is mount in the direction of your preference.

The purpose of this bike lock is to give maximum protection to your bike. Although it is heavy, the mounting bracket will help keep it easy to bring once riding the bike. Installing it along the cable will be easy if you connect it with the carabiner. If you can do it properly, the U lock and the cable will be installed in the bike and will not interfere in any way during the ride. But the most important thing is to find a way to properly secure your bike by maximizing all the capabilities of this premium bike U lock.

The only downside of this product is its weight. Once you are riding, it may give some discomfort and inconvenience to the rider. The need to install the mounting bracket properly should lessen the discomfort, but this will be another challenge.

  • With double deadbolt locking mechanism
  • Made with high-performance steel to provide power and resistance against attacks
  • The bike lock mount is easy to install
  • Cylinder’s protective coating prevents the surface from scratching
  • It comes with three laser-cut keys
  • Too much heavy

If you are a biker who wants to protect your investment, this U lock is an excellent option. It provides maximum protection and safety by providing resistance against attacks coming from outside elements. This product is one of the most robust U locks that I use on my bike.

6. Titanker U Lock Bike Locks

titanker u lock bike locks

When looking for the strongest U lock, you need to find something which also provides safety to your bike. Safety and protection should be the two main factors to consider if you want to take care of the bike to the fullest. And this is what this U lock from Titanker is known for, providing high-quality bike security and safety using a proven locking mechanism that will drive away all bike thefts.

The primary purpose of this U lock is to keep the bike protected and safe all the time. This bike lock is well designed and looks modern-looking, which for me, is excellent. The lock seems pretty secure and is easy to set up. The 4-combination keyless locking mechanism provides comfort and provides a great alternative to locking the bike. I feel that having a combination is more manageable than bringing the key all the time and the tendency to lose it.

In terms of design, I think that this bike U lock has a smoother design. The dial is covered, which will somehow hide the dial padlock to provide more safety. Unlocking the U lock is fast and convenient, while sliding the lock off the stem can be done in just a single click. I also like the thickness of the shackle and the cylinder. It looks durable and rugged and should withstand any attempts coming from criminals.

This product includes a cord that can be used to increase the security of your bike. At first, it might get tricky for you to keep it, especially when you are riding the bike. But you must find a way to secure it to avoid inconvenience. I wrap it around the front bar and into the front wheel, which works for me. Although it might cover the space dedicated to the water bottle holder, it was never a problem for me.

Also, the size of the U lock is long enough to cover the frame and the rear wheel and into the pole or bike post. Although, the cable lock is not long enough to loop around the wheel and closing it with the U lock. If you want to secure it, you need to have an extra padlock to the cable.

  • The heavy-duty lock provides more safety
  • A dust cover protects the cylinder and number combination
  • The lock is with anti-scratch properties
  • The shackle is made with high-quality zinc alloy to provide durability
  • Keyless locking mechanism
  • The lock rattles on the mount during the ride

This product is for anyone looking for the safety and security of their bike. This U lock is well built and is easy to use with its locking mechanism. You will no longer have to worry about a key and the possibility of loss. Just do not forget your number combinations.

7. Abus GRANIT XPlus 540 U-Locks

abus granit xplus 540 u-locks

Abus is one of the popular bike lock manufacturers, and they are known for producing high-quality and premium locking mechanisms. I am one of those bike owners who is a believer in the company and is satisfied with their products. In this review, we feature the Granit XPlus 540, considered as the flagship U lock it security for bicycles in this famous brand.

I say that the primary purpose of this bike lock is to give powerful theft protection to your bike, especially in critical places. So, if you are living in an area where bike theft is rampant and criminals are always active when it comes to stealing bikes, this U lock is an excellent option to have. Thanks to its tough square shackle and equally strong hardened steel-made casing, attacks from thefts will be prevented even with special tools such as bolt cutters.

Another purpose for this U lock is to provide all bike owners with a locking mechanism that protects the bike and offers high-quality craftsmanship. The first time I insert the shackle into the lock, I feel the sense of security and the toughness of this product from Abus. The size is just enough to get it around the rear tire of my bike to the seat post and secure it in a bike rack. I find no issue with its weight, but I have to admit that it is heavy.

Physically, this U lock is huge and massive. It is a heavy-duty lock that also includes a substantial mount frame. What I did with the mount is put it in the rear tire triangle of the bike. Doing this way will eliminate the usual interference and will help to make it easy to lock or unlock the product. In my opinion, this is one of the most outstanding U locks that any bike owner can trust.

However, one minor issue that I see in the product is its massive weight. Approximately, you will bring a 4 lbs lock along with your bike should you decide to use this one. If you are not comfortable using a heavy and huge lock, I suggest thinking several times before giving this product a shot.

  • A flagship bicycle U lock
  • Best for an urban setting and places with high-risk of bike theft
  • With double-bolt shackle and lock body
  • The casing is made with hardened steel
  • Square designed shackle protects hand tools such as bolt cutters etc
  • Huge and heavy

If you live in a high-risk community where bike theft is rampant, I suggest using this U lock from Abus. It will give maximum protection to your bike with its durability and toughness. The massive size will somehow intimidate and frustrate those criminals from stealing your bike.

8. DINOKA Bike U Locks

dinoka bike u locks

Many bike owners want it small when it comes to looking for a U lock in their bike. The small size and the portability will bring convenience and comfort, especially during the bike ride. With that said, this U lock from Dinoka is excellent for those bikes looking for a small and portable bike lock. I considered it one of the best mini U locks you can find in the market today. However, the small size will not prevent the product from giving maximum protection and security to your bicycle.

Probably the most outstanding feature of this U lock is the double-opening head. This type is much safer than a single-opening head U lock in terms of protecting it from bike thefts. I was also impressed with the cylinder, which looks very strong and sturdy on the outside. Thanks to the pure copper blades and an accurate structure preventing any form of breaking or opening.

Physically, this product is heavy-duty despite the smaller size. I feel that no one will dare to cut this lock without using a unique tool such as a grinder or a welder. Likewise, the chain was impressive physically, and the thickness should be enough to hold any attempt of cutting. The cylinder, meanwhile, is secure enough to prevent picking or any form of activity that will compromise the locking system.

Overall, this is an excellent U lock physically for your bike. The shackle and the casing is well coated with thick silicon rubber. The mount is also easy to install and should help in securing the lock while you are riding. I am impressed by the cable and its quality, and it comes with a hard coating that should protect the surface from degrading under different weather conditions.

The only downside I see in the product is the size of the bike mount. It is not universal and sometimes may not fit the frame of some bike models. If you happen to encounter this situation, you need to be creative in mounting it or replace it with another bike mount.

  • The double-opening head provides more security and safety
  • The heavy-duty cylinder will prevent any form of opening attempt
  • The casing is sturdy and durable and is made with hardened alloy steel
  • Small size and portable
  • Versatile in using other types of security tasks
  • The size of the frame may not fit some bike frames

This U lock from Dinoka is for bike owners looking for a small and portable locking system for their bikes. Even with the small size, the quality of this lock is top-notched and will still give maximum protection to your bike or other precious investment you own.

9. OnGuard Double-Team PITBULL U-Locks

onguard double-team pitbull u-locks

Creativity is what I best described in this excellent lock from Onguard. The only U lock offers a four-bolt mechanism system to prevent bike thefts from successfully stealing your bike. An adequately locked bike will restrain bike theft from their unlawful desire. It provides the maximum protection paired with one of the most amazing colors in all of the locks that I used, a graphical yellowish U-lock, which will make the theft stopped from doing his act.

One of the outstanding features of this product is the X4P locking mechanism system. What do you mean by this? This U lock comes with four-bolt locks: two locks located on the cylinder and two more on the opposite end or the upper side of the shackle. Meaning, if someone will try to cut one side, the shackle will still not move because it needs both sides to be cut for the lock to break.

To give your bike the ultimate protection, you can use the U lock in locking the frame and the rear wheel to a bike rack or a pole. Then you can slide the cable to the front wheel and running through the bike seat, and then attaching to the other end of the U lock. Doing this strategy will secure your bike, including all the moving and removable parts. Please note that the cable is only there to support the primary lock and increase the bike’s protection.

Another benefit of using this U lock is the comfort and convenience in installing the bike mount. You position it under the bike seat to prevent it from disturbing you during the ride. Another suggestion is to install it on the bike frame connecting to the bike seat, but it all depends on you and your preference. I also like that the lock is very secure once installed and should help in preventing the U lock from rattling during the ride.

The primary purpose of this lock is to give maximum protection to the bicycle. To do this, you need to find the best way to use it on the bike. This lock is heavy and massive. The cable is thick but is insulated with plastic to prevent the frame from getting scratch.

  • With unique 4-bolt locking mechanism feature
  • Breaded steel cable provides extra locking versatility
  • Easy to install bike mount
  • The warm yellow graphics decreases the desire of the theft to cut the lock
  • Keyway cover protects the locking mechanism from external elements
  • With five laser cut keys
  • Tendency to jammed if not used properly

The OnGuard U lock is for bike owners looking for a unique and advanced locking system for their bikes. The 4-bolt locking system is distinct in so many ways, while the 5-laser cut keys will give you protection if you lost one of them.

10. Amazer Bicycle U Locks

amazer bicycle u locks

The Amazer U that will protect your bike and lock is one of those 4-digit combinations locking mechanism which provides comfort and convenience to the biker. It offers the same advantage of carrying no keys and just using a 4-digit combination for locking and unlocking it into your bike. So, if you are looking for a U Lock to give your bike the ultimate protection, consider this U lock from Amazer is a good option.

One of the benefits of using this U lock is its ability to protect the bike’s frame from scratches. Thanks to the PVC coating of the shackle, it protects the lock and the bike from scratching and damaging the surface. We all know other lock’s tendency to scratch the surface of the frame because they do not have the same protective cover. But with this U lock from Amazer, your frame will be safe and sound.

Another feature that I see which is different from other similar combination U locks is the protective dust cover. This part is where the combination number pad is located, and there is a cover that protects the locking mechanism from outside elements. This part, in turn, will protect the lock and extend its lifespan.

Apart from protecting your bike, the other benefit that this product brings is the convenience of having a lock without keys. The option of using a 4-digit combination is excellent, especially for bikers who are clumsy and always have the tendency to forget and lost the keys. Also, if in case you forget the combination, resetting the code will be easy. Just follow the instruction found in the product manual.

The only downside I see in the product is the small numeric pad. It will be hard for those bikers with big hands to set the numbers because they are too small. An excellent suggestion to the manufacturer is to make it bigger.

  • Steel shackle is thick, which resist curing and leverage attacks
  • Keyless locking system
  • Easy to set combinations
  • Dust cover protects the numeric pad and prolongs the lock
  • Alloy cylinder prevents the surface from scratching
  • Small numeric pad

If you are a biker looking for comfort and convenience in a bike lock, I suggest using the Amazer U lock. It comes with outstanding features that will protect your bike and make it easy for you during the ride.

What to Look For When Buying a U Lock for Bike

best bicycle u lock

Before choosing and eventually buying a U lock, there are factors that you need to know to be able to guide you in selecting the right U lock for your bike. Please see the list below:

The Thickness of the Shackle

The best way to determine how strong is the U lock is to assess the thickness of the shackle. Usually, the thicker the shackle, the stronger the lock is. When the thickness is big enough, it will withstand the effect of all hand-made tools used in cutting the shackle. Although, the type of metal used also determines the durability and toughness of this part of your U lock.

Usually, the shackle with a thickness of less than 13 mm is vulnerable to cutting from medium-sized bolt cutters. If your U lock is size with 13mm to 15mm, a theft armed with the biggest bolt cutters can probably break and destroy your lock and steal the bike. If you want to be safe, settling for U locks with a shackle size of 16mm to 18mm will not give any opportunity to these criminals.

Number of Shackle Locks

The number of locks found in the shackle can also determine the strength of the U lock and its ability to withstand all threats coming from the outside. If you only have a single bolt lock in the lock, it means that it will only be cut once for the shackle to be removed from the cylinder.

If you have a double bolt locking system where the shackle has locks on both sides, it will need more effort from the bike theft to cut it twice, challenging his part. If you want to be extreme, try using the U lock with four shackle locks just like the one coming from OnGuard, which we earlier reviewed. This lock will give maximum protection and will undoubtedly protect your bike from outside threats.

The Quality of the Cable Lock

Most U locks come with an extra cable that will give additional protection and safety to the bike. However, the quality of the cable will also make or break the type of security that the U lock will give. Most of the cables are light to secure other valuable parts of the bike. But the quality of the protection it can provide will depend on the quality of the materials used in making the cable lock.

The most important thing is not to rely on the cable when locking your bike. It should still be the U lock as the primary locking system of your bike. The cable can also bring inconvenience when it comes to keeping it in your bike during the ride. But the most important thing is to maximize its usage in increasing the protection of your bike from theft.

The Size of the U lock

Unlike the thickness of the U lock, the size of it should be smaller to make the bike safe. The smaller, the better when it comes to giving space to the tool of the bike thief. But, the size should be big enough to secure the frame and the wheel to the bike stand.

The Presence of Bike Mount

The presence of a bike mount is a big bonus to the biker. It will bring convenience and comfort when bringing the U lock when you are riding the bike. The U lock is usually tough to transport, but with a bike mount, it lessens the difficulty of the biker.

Frequently Asked Questions

best bike u locks

Where to Put a U Lock on the Bike?

It will be a challenge to carry a U lock but using a bike mount is the best way to put a U lock on it. You can set the mount below the bike seat or to the frame connecting the post of the bike seat. Make sure to install it properly so that it will not disturb your bike riding activity.

Onguard vs. Kryptonite U lock: Which is Better?

I cannot say that one is better than the other. These two brands are popular in producing reliable bike locks and different types of security for your bike. Being at the forefront of making bike locks, Kryptonite has made many U locks, but the same goes with Onguard. Our team highly recommends both.

How to use U lock?

There are different ways to secure your bike using a U-lock system. When using this type of lock, you want to ensure that the U lock protects the rear wheel and the bike frame. It should also be attached to the bike rack or any other unremovable post.


Finding the best U lock for you bike is one of the best security investment you can have for your bike. It will give the maximum protection you need for your bike. But choosing the right one will be a big challenge for you, but our team is hoping that our recommendations and other relevant information we provide in this review will help you choose the right one for your bicycle.

4.7/5 - (18 votes)

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