KryptoniteNew York Standard Bike U-Lock, Heavy Duty Anti-Theft, 16mm Shackle with Mounting Bracket and Keys, Ultimate Security for Bicycles E-Bikes Scooters

The lock is sized perfectly to properly secure my bike. It is very durable and the design is universal. I highly recommend this lock.

Nothing is 100% safe even if you lock your bike up in your garage. But this hefty well built lock is definitely worth every penny. Super heavy duty and at a decent price. Great mounting hardware too. I feel pretty confident they ain't getting my bike unless it's a pro with a portable grinder. Even then it wont be easy or quick to disable.

Well, it's a Kryptonite U lock, so much better than any cable lock, (don't even waste your money on those if your bike has any value at all. You might as well hang a sign, "STEAL THIS BIKE!") If anything, use a heavy chain at the very least.The stronger "FAHGETTABOUDIT" version is just too impractical because it's so short. I want to be able to just slip this on when I park, not figit with trying to work it into a tight spot and maybe scratch the paint.It is ironic that the LIGHTEST bikes cost more, so we need a HEAVIER lock to secure them, and this monster lock is not light by any means.There's some misinformation about the "Protection" offer. It doesn't say you HAVE to have insurance (as some have said), but it looks like you DO need to register your Bike (and Lock) ahead of time. From their website:"Remember this is an OPTIONAL offer and you MUST register to participate in the Program." You also have to notify the police within 72 hours, and Kryptonite within 7 days. Probably the only sticky point is they want a pic of the broken lock or may even want to see it in person. A thief might just take the lock with him to prevent fingerprint ID.I've seen some complaints about it being hard to unlock after using it for awhile. I'm wondering if that's from thieves who tried to pick the lock but failed. They might have damaged the pins, trying to ram screwdrivers or whatever into it.I debated about buying two lesser locks for the same price as this one. Seems having two locks is preferrable, although no lock is completely theft-proof. Any lock can be defeated given enough time and opportunity, like leaving your bike outside overnight. I might eventually buy a 2nd Kryptonite down the road for my $2800 Trek Domane, maybe the "Lite" version to compliment this one.

This lock is hefty. I have no doubt that my bike is safe when I lock it up with this lock. It is large enough to easily maneuver around bike racks, street signs, etc. I have two issues with the lock, though. The first, is that the mounting system cannot fully support the lock for more than 2 days of riding before it loosens and the lock starts wiggling around, slipping down my frame, or turning to the side and interfering with my pedal stroke. I have had to use a small piece of velcro to secure the lock at the bottom of my frame to combat this, or just carry it in my backpack or back pocket. The other issue is the locking mechanism itself. It regularly snags and is often difficult to fully insert the key. I even spent 10 minutes once trying to dislodge the key from the key shaft because it got stuck. My solution? Beat on it until it loosened.Overall, this is a very sturdy lock that I would trust in any setting. While the downfalls are annoying, they would not dissuade me from purchasing this lock again.

Superb Lock

I mean, it's a Kryptonite lock, so I won't say much more about how strong it is. The mount is pretty useless on my eBike because all my tubes are HUGE. It just wouldn't wrap around any of the tubes and the triangle in the middle of the bike won't even fit the U-lock. Not Kryptonite's fault on that one. I did find a perfect place to put it, locking it between the triangle and the bottom of the seat post. The rubberized lock rests well there and doesn't seem to make any sounds while biking around bumpy streets.The lock is super smooth and the size of it is good enough to get around a lot of parking rails. Let's hope this prevents my bike from being stolen!

This thing is heavy and sturdy as hell. The included mount is okay, I wish the mount were a little sturdier, but it works adequately.

I use this to lock my e-bike. For that, weight isn't that important, but strength is. The bracket doesn't seem very secure and I don't use it. Locking and unlocking is straight forward. It is like using any other U-lock: the challenge is to get it close to something fixed (like a sign) that is small enough in diameter to allow the lock to go through frame and the fixed object. I use it in combination with a flexible cable so I can keep the wheels locked and to lock it to something fixed if I can't get the u-lock shackle around it. Hopefully it will keep the bad guys away. I