Kryptonite LK41051 KryptoLok Series 2 Standard Heavy Duty Bicycle U Lock with 4ft Flex Bike Cable
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Availability:
Only 3 left in stock, order soon!
Arrives
Tuesday, Jun 30
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Features
- Replaced with new and improved design in 2017 - check out our New U lock, it will send any bike thief running!
- 13mm hardened MAX-PERFORMANCE STEEL SHACKLE resists cutting and leverage attacks
- Includes 4 KRYPTOFLEX DOUBLE LOOP CABLE for securing front wheel or accessories
- Reinforced HARDENED CROSS BAR DESIGN provides increased protection
- HIGH SECURITY DISC-STYLE CYLINDER
- Center keyway defends against leverage attacks
- ANTI-RATTLE BUMPERS reduce noise during transport
- Rotating dustcover protects cylinder
- Includes NEW TRANSIT FLEXFRAME-U transportation system which allows for versatile carrying
- Protective vinyl coating
Description
Replaced with new and improved design in 2017 - check out our New U lock, it will send any bike thief running!. 13mm hardened MAX-PERFORMANCE STEEL SHACKLE resists cutting and leverage attacks. Includes 4’ KRYPTOFLEX™ DOUBLE LOOP CABLE for securing front wheel or accessories. Reinforced HARDENED CROSS BAR DESIGN provides increased protection. HIGH SECURITY DISC-STYLE CYLINDER. Center keyway defends against leverage attacks. ANTI-RATTLE BUMPERS reduce noise during transport. Rotating dustcover protects cylinder. Includes NEW TRANSIT FLEXFRAME-U transportation system which allows for versatile carrying.Protective vinyl coating.2 STAINLESS STEEL KEYS. Key Safe Program.
Brand: Kryptonite
Special Feature: Anti-Drill
Lock Type: U-lock
Item dimensions L x W x H: 9.02 x 4.02 x 1.18 inches
Material: hardened Performance steel shackle
Brand Name: Kryptonite
Recommended Uses For Product: Security
Number of Pieces: 2
Included Components: Kryptonite Kryptolok Series 2 Standard Bicycle U-Lock With Transit Flexframe Bracket (4-Inch X 9-Inch) With 4-Foot Flex Cable, Transit Flexframe Bracket
Model Number: LK41051
UPC: 720018001072
Model Name: Kryptolok Serie 2 Ls + Flex
Global Trade Identification Number: 72, 16
Manufacturer: Kryptonite
Manufacturer Part Number: 001072
Additional Features: Anti-Drill
Lock Type: U-lock
Controller Type: Hand Control
Control Method: App
Style Name: Original
Color: Black
Shape: U Shape
Material Type: hardened Performance steel shackle
Finish Types: Vinyl
Item Dimensions: 9.02 x 4.02 x 1.18 inches
Item Weight: 1.5 Pounds
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Jun 30
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
I had minor reservation about spending so much money on a bike lock, but I am glad I did. This lock holds up to the name Kryptonite, because it's made to stop Superman! Not really, I'm sure he could destroy this, but anyone short of superman has no chance. The U lock is VERY thick and sturdy. It has an adjustable mount which allows for easy attachment to the mounting bracket. The lock itself uses a unique key, and has a cover to help protect against rain and other elements. The flex cable as well is much thicker than some other cables I've had in the past. It comes with a velcro strap for easy storage. The bike mounting bracket itself, while it works, is a bit odd. It uses a mesh strap, which does allow for easily mounting to many different shapes and sizes, however it only relies on a rubber piece to prevent sliding. I haven't had any issue, but I do worry that this could be a problem in the future. The mount, while a bit more complicated than it could be, does allow for a fair bit of versatility, which is nice. This lock actually comes with a warranty that I found to be pretty great, however, there are some things to know ahead of time in regards to it. It covers up to $500 of a motorized vehicle, or $1500 on a bicycle, and will cover either A) Your insurance deductible, or B) value, based on which is cheaper. You have to register the product within 15 days of purchase, and the registration costs $10. As well this warranty only lasts 1 year, and only covers thefts due to product failure, IE the lock being cut etc. Part of the reason for my purchase of this lock, was due to the warranty, I just wish I knew ahead of time that it costs $10 extra and is only good for 1 year. I am still very satisfied with the lock, however, and felt that I've gotten what I paid for, as opposed to buying some cheaper cable for $5 or so.
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Reviewed in the United States on April 23, 2013 by Chris Tucker
Great lock. I like the combination of the u-lock and cable to be able to lock both wheels, or a saddle or helmet as well. Lock looks sturdy but obviously has not been tested by thieves yet ;-) Easy to attach the bike holder to the bike with the wrap. Great product, especially for the price point. I review often and carefully choose the star rating in an unbiased manner. Star ratings are earned, never given. 1 Star: Stay away! The product is either of extremely low quality, was poorly or even deceivingly described, or parts of the product details or description do not match up with reality. I suggest not to buy the product as your money can be better used elsewhere. 2 Star: Well under expectations. The product is not completely worthless, but does not live up to the expectation a normal user would have given its price and description. Again, I would suggest you can find better value for your hard earned cash. 3 Star: Neutral. Largely met the product description and details but I would not order the product again. Some particular features, its design or looks, or the price may make this somewhat attractive, but overall I would still not recommend this to my friends. 4 Star: Nice product. All my expectations were consistently met. Good quality, and you get what you are looking for given the description. It's a thumbs up without the enthusiastic smile. Good product, but not stellar in any way. 5 Star: Outstanding product. All my expectations given the product description were met and in part exceeded. Unreserved recommendation for a well-made product. This would be the kind of product I would recommend to friends putting my reputation as a honest and well-meaning recommender on the line.
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Reviewed in the United States on October 3, 2016 by Mark Bourdain
I purchased this lock for use at a university to keep my mountain bike safe. I find the lock to be perfect as it being longer than most U-locks helps me out a lot because my mountain bike has an XL frame which common U-locks don't fit. The only issue I had was the cable which was too short to run through my wheels which have quick releases. After receiving this, I had to use my older cable lock as a secondary lock to keep my wheels safe. The mount is a great add on as it makes it much easier to carry! I had a few issues with the keys, but I will explain later the solution to preventing issues... Pros: -solid lock; seems really hard to cut, and deters thiefs from even attempting to steal your bike -mount makes life easier when biking without a backpack -easy to open and close if you operate keys properly Cons: -the little metal mount on the "U" part of the lock loosens over time(not a big issue, you just have to push it sometimes so the lock locks) -key is pretty fragile and can break easily -cable is too short The Key: -make sure you push it ALL THE WAY IN before turning -rotate a FULL 180 DEGREES to unlock or lock -if the key does not come out, DO NOT pull or it could snap, just wiggle it or rotate it the 180 degrees again till it comes out with ease(DO NOT FORCE) -Make sure to push the metal mount piece on the "U" part of the lock all the way up as it takes up space that the lock needs to lock as it WILL NOT CLOSE unless the metal piece is flush Besides these few minor issues and the cable being too short, I'd recommend this lock to everyone looking for a solid lock to protect their bikes! Extremely easy to use and they even guarantee that your bike will be safe! Hope this helps!
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Reviewed in the United States on August 25, 2013 by Naveen
I bought this lock firstly for the U-lock, but also because of the included cable. The U-lock is great. A little heavy, strong and sturdy. Drop it and it nothing happens. The metal is nearly impossible to cut, unless someone is walking around with a chain saw, and the lock seems to be designed to be pick-resistant (not easy to pick the lock). I wasn't able to figure out how to attach the U-lock to my bike with the included hook that you'd have to manually attach to a post on your bike. The directions are practically unreadable and the pictures are confusing. And the rubber parts that are supposed to hold the hook together in the right way break apart easily. If you must attach it to your bike, then get another lock with a better hook, or find another hook itself. Or do what I do: hang the U-lock on my bike handle. I actually like that because it makes for easy access to take the lock on and off. About the cable: There is a picture on the package that shows a suggested way to hook up your bike using both the U-lock and the cable, which is to lock up the back wheel and frame with the U-lock, and use the cable to wrap around the front wheel and lock the free end with the U-lock. I found that that is the best way to do it given the cable's rather short length. I have a small bike and the cable isn't long enough to wrap around my whole bike. Deal is, buying the U-lock and cable together, although you can buy them separately, gives you a way to lock up both wheels and frame securely with well-known U-lock security. I recommend this product to everyone.
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Reviewed in the United States on June 17, 2013 by Elpeciss
Keeping your bike protected is something all owners think about. To secure this piece of mind, it is best to use a lock. Whether it be for mere seconds or days, it is always best to lock it up to a secure object. Although no lock will deter one hundred percent of theft, I believe this lock is one of the better ones. It is strong and complicated enough to scare away most thieves. The ideal user of this product is anyone with a bike who is looking to deter theft. The lock comes with two essential items, the U-bar and the four foot cable. The steel bar is long and wide enough to cover the frame and one tire. The cable can then be used to wrap around the other tire to make it even more secure. Set up time is minimal as it usually takes less than a minute to install. This lock is also resistant to weather. It is always best to store your bike indoors, but if needed, the lock will be fine outdoors as you can slide the cover over the keyhole to reduce rust and dirt getting inside the lock. The lock is quite large, but it can be easily stored on your bike with the mount leaving no reason to have to carry it around in a bag. This mount is also quiet with little noise and rattle, leaving a smooth ride for you. To provide you with more piece of mind, the company offers a lifetime warranty on the lock if it has a defect. If you register your key set, there is no need to worry about paying for a new one as the first replacement is sent free of charge. Another positive is the affordability. At $30 you get a strong, sound lock that will do its job. This makes it a great lock for college students who do not necessarily have the means to buy an expensive lock. The reviews are even comparable to the more expensive locks. As previously stated, no bike is one hundred percent safe. However, you can feel more secure with the strength of a Kryptonite KryptoLok protecting your bike.
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Reviewed in the United States on February 3, 2018 by T Hunke
The good: The lock is very sturdy. I never worried about my bike getting stolen when using this lock. The length makes it pretty versatile when trying to get my bike locked up to various things in the city. Comes with a cable and two sets of keys. The bad: I had a hard time figuring out where to mount the bracket on my bike. I initially had it mounted by my rear wheel but after only a week or so of riding, the part that connects the lock to the mounting bracket became loose and started turning the lock into my wheel. I would have to stop and adjust the lock so that it was no longer rubbing against my rim. I'm worried that the lock may have warped my rim while rubbing against it. Next, I moved the mounting bracket to the bottom of the bar on my rear wheel so that gravity would just let it fall naturally without touching the wheel. The mounting bracket itself became loose and allowed the lock to turn in a way that made it touch the back of my foot when pedaling. After this, I rotated the mounting bracket to an angle that allowed the lock to be out of the way of my feet. The lock has fallen off twice while riding since doing this so I finally decided to return it. Another issue I have with this lock is that the key doesn't want to work half the time. Sometimes I have to spend a couple minutes jiggling the key around until I can get it to unlock. Bottom Line: This lock would probably work just fine for someone who has no interest in mounting the lock to their bike frame. I don't always ride with a bag so a good mount was necessary for me. The lock seems very secure and made with good material. I have returned it and ordered the Kryptonite New York lock. I'm hoping that the mounting mechanism will be much better on this higher end lock.
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Reviewed in the United States on April 28, 2017 by Amazon Customer
I've used this U-lock on and off for about two years. Just a few weeks ago it failed as I could not get it to lock. After emailing Kryptonite's customer service about this issue, they were not hesitant send me a replacement free of charge! It was nice to not be hassled with a fee or patronized about the non-functioning lock. I've been using the new lock for a few days and it is working flawlessly. The below pros and cons are representative of each lock. Pros: +The design is well thought out and the mounting mechanism make it very convenient to transport with the bike. My favorite part of this product. +I feel that the steel shackle is adequate in protecting my bicycle. My philosophy is that if someone were to motivated enough to try to cut through a steel U-lock, they probably would be able to accomplish the same on any larger U-lock with a little added time and effort. +With a little work, I can lock two bikes to the same post or rack. +The included cable was always a plus, but paid off big time when I was without my U-lock and had to use it with a standard pin tumbler lock to secure my bike. Cons: -The lock is a tab bit sticky, and sometimes is a hassle to lock and unlock the bike (though this may be due to the disc locking mechanism). Conclusion: I'm confident that this lock would protect my bike, and would buy another Kryptonite lock without hesitation.
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Reviewed in the United States on September 17, 2016 by Logan S.
Good quality lock. It seems like a quality piece of gear to keep your bike safe. It is a nice, size not too big not too small.
Reviewed in the United States on January 15, 2026 by Darth Caffeine