Kryptonite Keeper Bike U-Lock Standard with Braided Steel Cable, Heavy Duty Anti-Theft Bicycle U Lock, 12mm Shackle and 10mm x4ft Length Security Cable with Mounting Bracket and Keys

This bike lock has served me very well over the years, very happy with quality and durability.

Great bike lock with plenty of space for easy locking in different positions. The mount is convenient, so there’s no need to carry it separately. The flexible cable secures the front wheel or helmet, and it’s lightweight too.

I was wary of buying this because of the reviews claiming the lock was fiddly to use with the key. I went ahead anyway, and I'm glad I did because it's a really decent lock for the price. Lots of people have said that it's too small, but I've had no trouble at all fastening the lock around a rooted post and my back wheel so it's plenty secure, and it's a standard sized bike. The fact that the base of the lock actually detaches makes it easier in my opinion, though this is something others seemed to dislike. The only reason I've gone for 4 stars instead of 5 is because I *did* have an incident with the key not working very recently, which is what I assume others were talking about, but I was able to see exactly what the issue was and know how to prevent it in the future (hopefully!). Basically, the best way I can think to describe it is that the channel of the lock is made up of segments that, when you put the key in, all twist at the same time. However, when you pull the key out after locking, if you slightly twist the key at all it twists those top few channels, but not the lowest ones. As a result, it's then hard to put the key back in, because the channel is no longer straight (I hope this makes sense!) But the fix is literally just to put the key in as far as you can get it, then twist gently until the channels re-align and you can push the key in all the way. I know that sounds complicated, but it's really not, and if you just experiment with the lock when you receive it, you'll see what I mean and how easy it is to resolve. If I end up having this issue again and it's worse, I'll edit my review, but for now I would say don't let the other reviews put you off. It's a good size, sturdy, and not tricky to use once you suss it out. Also, I noted that some reviews criticised the lock because their bike got nicked, but based on the photos they had secured the bike with the provided cable and then closed the cable with the heavy-duty lock. This is NOT how you lock a bike! Never have the wire cable as your primary source of security – secure the back wheel of the bike to a rooted post and, if you want the extra security, you can loop the wire through your front wheel.

Very good lock

Sturdy and looks like the bicycle thieves will have their work cut out

This works well. Unfortunately I got my bike wheels stolen but they couldn't get the frame due to this lock. Moral of the story , lock your wheels with the frame!

Good one

I've been using this for over a year as a lightweight D-lock for my bike. These locks are ubiquitous in my area - everyone seems to have one. They're cheap and look good quality BUT unfortunately have a cheap key and a fiddly lock without any weather protection. When I use my previous, fuss-free, heavy-duty D-lock for our child trailer, it's obvious how poor the Kryptonite is in comparison. I still end up using this daily as it's small and light, but I often find myself cursing it when struggling with the key. Frequent WD40 helps. I cycle about 8km daily on the school run, down a canal path and over a few cobbled stretches, but the mount has always been solid. I see it gets bad reviews, but for me it's the best thing about the lock - I tightened everything right up when I first bought it, and haven't had to adjust anything since.

It was Nice while it lasted. After a month, the lock mechanism kept getting jammed. I returned it

Veo las muescas de que lo han intentado romper varias veces, pero no lo han conseguido. Mi bicicleta duerme en la calle y tras un año en la calle se ha oxidado, cierra peor pero sigue funcionando.

鍵穴の建て付けが悪くグラグラついていた 1週間目でささらなくなり回らなくなった 不良品

Excellent lock. Very strong

We have had our kids bile stolen a lot we live in a apartment so we got this and it’s never been stolen and it is made of good quality