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
Best lock I've ever used.

I stopped using cable locks after realizing individuals do not even need tools to break those locks, when I had my first specialized bike stolen while it was locked up overnight. I have now been using kryptonite u-bolt locks for years without any successful theft. Well, over the last few days someone (or several someone's) have attempted to steal my bike (Transition Bottlerocket), while it was locked up for the day (yes, these arrogant thief's are trying to steal bikes in broad daylight). Well, this is how my several year old bike lock looks after successfully preventing the thief(s) from taking my bike. I just upgraded and bought the "New" Kryptonite New York model / version. Now, only thing I wish these locks had was a camera to take pictures / video of the surroundings when the lock is jostled... this would capture the perpetrator(s) who are attempting to steal personal property, and could text / email / store them in the cloud.

Secures my Bike in NYC

SECURE - I use this product to lock up my bike around New York City. The U-lock feels strong and durable. It is also big enough that I can easily attach both my bike frame and one tire to a bike rack. With the added cable, I can then secure the other wheel by looping the cable through the unlocked wheel, putting one end of the cable through the other end, and then locking the loose cable end to the U-lock. The cable feels like it could be cut with very strong wire cutters, so it is more of a deterrent than anything else. However, I feel the U-lock/cable combination is a better solution for my bike than carrying around two U-locks. I’ve used it several times a week for the past three months and neither my bike not my tire has ever been stolen. BRACKET - Speaking of carrying around U-locks, I really like that this product comes with the FlexFrame Bracket. The Bracket easily attached to my bike without much work. It feels very secure on my bike frame. The U-lock easily attaches to the bracket and easily comes off by pressing the lever on the bracket. When the U-lock is attached to the bracket, it feels very secure. Neither the bracket nor the U-lock have ever fallen off my bike, despite much jostling. EASY LOCKING - Locking the bike is very quick and easy once you get the hang of it. Three things to be aware of: First, there is a keyhole cover that you have to swivel out of the way in order to access the keyhole. I think it is there to keep dirt out of the keyhole but I always just leave it exposed and have never had a problem. Second, when you unlock the U-lock it comes apart (intentionally) into two pieces- the straight bottom part that has the lock/keyhole, and the rounded U-bar part. One end of the U-bar curves slightly outward making a little ‘J’ shape. This means that the J end can only be slipped into the correct end of the straight bottom part. You have to put in the J end first, and then the straight end can be put into the straight bottom part. I like this feature because it adds another level of protection. Finally, just be aware that the key has to be in the unlock position in order to put the U-lock back together. OVERALLY IMPRESSION - I love this lock and can’t find anything wrong with it. It has held up well in the past three months and only has some minor cosmetic scratches.

It does its job.

Despite seeing some harsh reviews for this lock, I’m giving it five stars for a couple of reasons. Firstly, it’s prevented my bike from being stolen so far, and I can’t ask for more than that. I mean, it is sort of the entire reason I purchased the lock in the first place. With that in mind, there would have to be some meaningful drawbacks for the lock to have less than five stars. For the sake of comparison, my previous bike lock was a cheap plastic-coated cable with a key lock. While the length and flexibility was nice, it seemed too thin and flimsy, and I was frequently told that bicycle thieves could cut it with ease. Additionally, the locking mechanism frequently malfunctioned, making it difficult to unlock it. By contrast, every part of the Kryptonite U-lock is thicker and more robust. It simply looks and feels far more secure than the previous lock. The locking mechanism itself is also far superior. There is a sliding cover to protect the keyhole from the elements, an excellent feature for rainy Corvallis, OR. I have yet to notice any malfunctions or sticking points when unlocking it. My one minor complaint is that the entire U-shaped portion of the lock completely separates from its base whenever I unlock it. I understand that this ultimately makes it easier to put the lock on more parts of my bike or cover larger distances, but I rarely actually need the lock to completely separate; it would be just fine if it functioned like a normal padlock, with one side of the U-shape pivoting when unlocked. However, this is a minor quibble, and I just have to make sure that I’m holding both parts of the lock before I turn the key all the way. Anyway, the inclusion of a couple useful accessories outweighs the small “separation” drawback. The sturdy steel cable can be used in conjunction with the U-lock, which is handy to secure both of your wheels if your bike is going to be left unattended for a long time. There is also a small device that attaches to your bike frame, allowing you to easily holster the U-lock when you’re bicycling. Overall, this Kryptonite U-lock has done its job, and that’s all I can ask for. My bike hasn’t been stolen, and the lock is a huge upgrade over my last one. Finally, although I could have knocked off a star over the annoying issue of the lock separating, there are two useful accessories that easily outweigh the slight inconvenience. 5/5 stars.

When using the bike lock I feel like the bike is very secure and I have had ...

When using the bike lock I feel like the bike is very secure and I have had no issues using. The added 4ft cable works great when I want further security or if the pole I am attaching the bike to doesn't fit. The only downside is when I'm biking where to put the lock, the attachment to secure the lock to the bike when riding did not fit on my bike properly and would jostle around. However, I do throw the lock into my backpack when riding and I have had no problems. Would recommend

Sturdy Bike Lock

This is a great bike lock. I was hesitant to spend a bit more money on a bike lock, but I have never once questioned it getting stolen on my college campus. I stopped using the extra cable after a while because I was able to get the bike frame and front wheel easily attached to the bike racks with just the U lock. The key can be a bit finicky to get in or out, and it happens fairly often, but with time you get used to the right way to jiggle it to get it to work. I would definitely buy it again, although I expect I would have the same slight annoyance with the key. Also, the mount worked fine, and have had no issues. I have had the lock for about 5 months, and it is holding up great. Pros: - Very sturdy - Key lock that can't be opened with the "bic pen" method - Perfect size U-lock - 2 sets of keys (and another 2 are available for free from Kryptonite if you lose them) - intimidating appearance to potential thieves. Cons: - key does get stuck in the lock frequently - the metal piece on the U-lock that latches into the mount came loose after a while, but it was easily tightened to its original position with an allen wrench.

Great lock and customer service.

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.

Feels very secure

I purchased this lock a little over a year ago, and it's held up great. I don't think you can go wrong with this lock. It feels very secure. Something to keep in mind though: The U Lock is very big. It comes with a bracket to mount to your bike so you don't have to carry it on your body or in your bag, but the lock is too big to mount on my bike anywhere without getting in the way of something (e.g., my legs when pedaling, my rear rack, my water bottle cage), so I have to either carry it on my body, or secure it to my rack in a weird way so it doesn't hit my back tire. So, yeah, if you buy this lock, you'll get your money's worth. Just be prepared to deal with figuring out how to carry it with you.

It works.

To be honest there isn't much to review here. I live in a somewgat okay part of town . Still think it's good to have some security though. This lock is protecting a Razor EcoSmart Metro. A 350 dollar scooter. It hasn't been stolen... Hah! I don't dare leave the scooter outside alone for more than 10 minutes. I have seen people break locks before. This thing is just like a... "Come back when you are ready..." Kinda thing. The lock is a little iffy at times, not taking the key, not turning when the key is in, stuff like that... It works though. And it looks mean. I guess I can't complain! It works!

Awesome Lock

Note: NO ONE HAS ATTEMPTED TO STEAL MY BIKE. I am NOT qualified to evaluate security. I will be evaluating other aspects. This lock is the best, in my opinion, for the value. It is weather-resistant (to a degree), rugged, secure, and easy to access. I have bought two so far: one for me, which I have switched between my Trek 820 MB and Trek 2000-something RB, and one for my girlfriend's Slingshot. They are very different bikes, but I've found unobtrusive spots on all of them to put the lock. Though on the Slingshot she had to relinquish her bottle holder. *The attachment Kryptonite includes should not be taken lightly.* It is GREAT. Makes it much less a hassle to lock up the bike, and is very customization in terms of position. Much better than others I have seen. YOU NEED TO TAKE CARE OF YOUR LOCK. My roommate and I both happen to have bought this lock. I oil mine regularly (once every 2 months or so) with WD-40; he has maybe twice. After half a year, mine is working fine (albeit showing rust inside hinging non-locking part), but he's trying to get his unstuck. Both of us have to leave our bikes outside and ride everyday. Oh, and I've dropped my lock at least 10 times on concrete. It's fine, but the plastic shield around the lock doesn't have a catch anymore. No big deal.

Secure, heavy, and big

This thing is heavy, but makes me feel secure. It was a tough thing, finding a lock to trust. I did a lot of reading of reviews and lock-breaking tests. Spoiler: they all fail, given a sufficiently motivated thief with enough time. However, in a world where my bike only needs to appear more difficult to steal than the others parked nearby, this lock fits the bill. FWIW, I park overnight in my home garage and during the day in front of City Hall. I'm glad that I decided to get this 9" U-lock, rather than a 6" or 7". The bike rack posts at work are pretty thick and I can just barely get this 9" around a post, my frame, and my back wheel. I also use the 4' cable to secure my front wheel. The only downside to that security is that this thing cannot mount anywhere on the frame of my bike. Even if I remove my frame pump, my bottle cage gets in the way. (I have a size 49 frame, so bear that in mind.) I've been carrying it in my pannier lately.

Full Reviews