Kryptonite U-Locks are some of the best dang locks I've ever seen, strength-wise. I used to own one myself, and the shackle and body were dang near invulnerable. However, the actual lock is not. As far as I've ever seen, the lock on a Kryptonite is just a tubular lock. So you can either buy a tubular pick, a tubular lock saw, or make tubular hand picks like I described in a previous post. (Search for all my posts if you want to find it. . .I'm not going to repost it here.)
That's really all there is to it.
"Sesamee" locks are commonly used on bicycle chains, briefcases and padlocks. Sesamee is just the name of the most popular brand of numbered-wheel lock. There are usually three or four wheels, lined up next to each other. Each wheel has the numbers 0 through 9 on it. You turn each wheel to the right number, and the lock opens. Simple, right? Fortunately for us, almost all of these locks have one thing in common: the combination is changeable. In briefcases, for instance, once the briefcase is open, you can press a small switch inside, turn the wheels to the new combo you want, and release the switch. This resetting function is what gives us a means to defeat this lock.
You see, each wheel has an individual axle that it spins on. And these axles have a notch cut into their surface that the wheel rests in. When the combo is changed, the wheel gets lifted up out of the notch, gets turned to the new number, and is set back down in the notch again.
So take a thin, flat piece of metal (such as the handle end of a tension wrench) and insert it on the right side of the first wheel, letting it touch the axle inside. Turn the wheel slowly, one number at a time, letting the wrench slide over the surface until you feel the corner of the wrench handle drop into that notch in the axle. Whatever number that notch is next to is the correct number for the combination. Do the same for the other wheels, feeling for the notch, finding the correct number, and you've just defeated the lock.
Sometimes you may get all the way through, and suddenly discover the lock still isn't opening. It's very easy to think that you've got all the notches (and numbers) lined up correctly, when in fact one of your wheels may be just *one* number off in either direction. Make sure the notch is centered, and not tilted to either side. The notch has to be lined up with that little marking line you would normally line up the combo numbers with.
There is a "Sesamee Padlock tool" sold by many companies for around $20 or so, but this is a waste of money. It's only a flat piece of metal with a handle. Just use your tension wrench. Also, you may encounter padlocks that do not have any room for your tool to be inserted beside the wheels. They're just manufactured too well. You could go to the trouble of drilling a small hole in the case next to each wheel, but then you may as well just try to bolt-cutter the thing open. For practice and educational value in the comfort of your own home, though, it might be worth it.
Hope you all enjoyed this Tip. Good luck, and happy picking!