Kryptonite Kryptolok Series 2 LS Bicycle U-Lock (4-Inch x 11.5-Inch)

read lock reviews for over a month. came back to the kryptonite locks. Purchased this after I realized the other U-lock I have from 1991 is Kryptonite brand also. Needed additional lock setup as graduated to a tricycle and a regular cable lock was cut while I was in the grocery store. The Kryptonite U-lock saved me, so now I have 2. One for the front and one for the back.

I live in Oakland, CA where bike thefts are common. This bike lock is sturdy and I haven't had any problems w/ the key/lock mechanism like some other U-locks. It's large enough to secure my bike to street signs, meters, etc, when there aren't any bike racks around but not super heavy like heavy-duty chain locks. I would not feel comfortable leaving my out overnight with this lock, but overall a good lock.

The lock itself works as expected but the EZ Mount is not "EZ" at all. Removing it is a pain (that is if you manage to get it off without breaking it). It also keeps the lock kind of far (about half an inch or so) from the bike, which will be very inconvenient depending on where you install it. I returned it and will look for a model with a better mount.

Nice sturdy lock. It is slightly longer than most U-locks I've seen, which is very nice for locking up the wheel along with the frame to a bike rack.The only complaint is that the key sometimes doesn't go all the way in, but it happens a lot less once you get used to it.

Very durable and has met the test after a few days. Someone tried to steal my bike with a saw and they gave up. Highly recommend lock!

Very difficult to open the lock, I have to turn many times before it opens. Very new, and hasn't rained so it didn't rust. I tried to add oil to loosen it, however this did not help. Simply a faulty product.

I needed a lock that was a) long enough to easily lock both wheel and frame (for my hybrid bike which sports a longer-than-average front wheel to frame distance) and b) light, but still strong. This was the only lock I could find that fit this bill, and overall it has been good-but-not-great.* Comparison to Kryptonite's other locks: Kryptonite's next tier up, the "Evolution," is quite a bit heavier. According to my bikesmith, the only difference they noticed when they've had to cut through these locks with an angle grinder is that the Evolution takes slightly longer to get through. The "New York" lock weighs more than my bike, and the "Keeper" is not appropriate for a mid-high cost bike. That made the Kryptolok series an easy call. (BTW, after I bought the lock, I started noticing locks on my campus -- Kryptolok is easily the most common brand.)* Locking mechanism: The other reviews nailed it -- the key sucks. It sticks a lot, especially in the cold. But it won't likely break off (like some users reported) unless you are twisting it like a maniac. Hopefully Kryptonite will make an improvement here. Not sure where else to turn, though.* Warranty: This is garbage. You have to pay to activate, and the theif has to leave a piece of the broken lock for you to claim. Useless.* Dimensions. Length is right, but the width is still a little thin for my hybrid tires. I can't lock my bike to parking meters, which sucks. What I really needed was a 5x11 lock, but I didn't see any of these on the market... Anyone with a hybrid or MTB that doesn't need the extra length should definitely stick with Kryptonite's 5x9 lock.

After reading some of the other reviews for this product, I was nervous that the key or the locking mechanism itself would be faulty or unreliable; however, this is entirely not the case. As long as you just insert the key the whole way, it works like a charm. The long construction is great for securing both your frame and wheel, and it's obviously a very solid lock.That said, the people who criticized the mounting bracket were entirely right. It takes way too much force to get the lock on and off, and it's especially bad when it's mounted to your frame and you don't have much leverage. The first time I tried to get it off the bracket, when it finally gave I wound up slamming my hand into the bike and tore half the skin out from under my thumbnail. Not pleasant. Since then I've just carried the lock in my backpack.