Kryptonite  KryptoLok Combo U-Lock

I have been using mine since 2009. Thieves hate this lock because it has no key lock for them to pick or freeze out. I have had one attempt on mine-someone tried to see if my combo was easy, and damaged the lock by breaking the plastic shield that covers the combo because they could not figure out where the digit wheels were located. The lock still works fine. It is heavy to carry around but as you can see in the photos I used the bike mount that came with it to attach it to the bike. It can be hard to see the digits at night sometimes--but just use your cell phone it illuminate it. I like most that you never have to remember to take the key. The combo's are re-settable so you can change as often as you like.

From day one it was defective, it would not close then I lifted the “O” rings up and it closed. The numbers are very hard to turn. Now who would you normally buy a combo lock for say maybe a child so they do not have to hold a key. So let’s make the numbers hard to turn, the button hard to slide to open. Of course have it jam while it’s at school so I can stop my whole day of work to get this lock off the bike rack. It obvious that this lock is complete garbage and to makes it worse do this to a kid, thanks Kryptonite!!! The only good thing was that it took a while a saw off and bash it with a 4 lb small handle sledge hammer to get it off.

This lock served me for years and was very easy to use. You do need to make sure you lock it at an angle where you can see and access the dials. The numbers are difficult to read at night. Sadly my lock was broken by a leverage attack in broad daylight yesterday and my bike was stolen.

I ride around downtown everyday and am usually locking up between a few minutes and a few hours, occasionally even overnight. This is a pretty tough lock and it's nice knowing that I don't have to worry about losing or forgetting my key. Recently someone had tried like hell to break my lock. They must've had some strong tool because they were able to bend it somewhat but fortunately the lock was too tough as they gave up on it. It was a little hard to unlock after the incident due to the damage taken and even though I now need a new lock, it stopped a thief!

I've had three of these locks. I love this medium-security and convenient lock, but I've had some problems: 1) tumblers have failed/got sticky; 2) combo will jump/change if you jamb the lock closed if the combo is just a bit off; 3) lock will sometimes not close unless clicked closed hard. Also note that you need to clearly see the combo lock to open it...so if you ride a lot at night, this can be a pain. That said, Kryptonite has been 100% supportive of all returns / exchanges. I really wish they'd improve the quality.

Disappointing product. Within weeks both plastic pieces had fallen off and within a year I had to have the police cut it off because it was jammed up.

My neighbor was able to pick open my Kryptonite KryptoLok Combo U-Lock within 90 seconds. He had never tried picking this kind of lock before and I couldn't believe he succeeded. I won't post the video of him picking it. But, get a keyed lock instead, not a combo. Use two locks, different kinds is best. If this lock must be used, lock /w number above the unlock button (black part of the lock post upwards), this won't prevent it being picked but it could hinder or slow an attempt.

I have had this lock for pretty close to 10 years and it's still functional - partially rusted out and the rubber is coming off of the "U" part. The length of time I've had it should be a testament to the quality right there. Having a combo instead of a key is so convenient for me as I tend to forget keys sometimes, and it's also nice to have the option of not having to carry keys on a ride. The only problem I've encountered is that you have to be very careful to close the cover over the combo numbers if you even *think* it's going to rain - got left out a few days in a row in the rain and had to do some serious cleaning and greasing to get the numbers functional again, and to this day they are not near as smooth as they were before that. Sometimes it requires using a key or coin to get good enough leverage to make the numbers turn. I manage by only ever rotating one number when I lock it up and leaving the other 3. And always closing the cover!

The lock came with a mount but no instructions. I could not find instructions online anywhere and after a few hours I figured it out. However, on my first ride with the lock it fell out of the mount despite being as secure as possible and I lost the lock. $50 straight down the drain.

I wanted to post because of all the negative posts i saw related to this lock. I'm looking to buy a new one as I'm getting a new bike, and have every intention of buying the same one I've had for years. it's served me very well, and my partner's still works great too. The best thing about it is not having to worry about a key, and being able to leave my bike locked up and having someone else able to borrow it or pick it up for me. Anyway, mine dropped off my bike (my fault, i was using a clip that wasn't tight) and was promptly run over by the tires of an MBTA bus. It is a bit grazed looking now, and does not lock or unlock as smoothly as it used to, but that was more than a year ago and it's still fine! Granted, i've had it for about 8 years, so maybe they don't make them like they used to? But i'm willing to try again.