You've heard of the old "credit card" trick with a door lock? Shimming is a way of opening a lock by pushing something inside the mechanism to release the catch. Shimming a padlock involves sticking a thin piece of metal in between the bolt and lock body in order to force the lock to release. It doesn't require any skill and it is fast, so it is a method thieves would use in the field.

I assume you can do the same thing to a U lock(?)

It all depends on the design of the lock. You would need a bigger shim, but nothing would preclude that scenario.

Look at it like this, in order to make a lock secure they have to machine the parts to very tight tolerances, which raises the cost of design and materials. We dont live in an ideal world either. Your lock is going to get rained on, get dirt blown in it, road gravy splattered on it, you name it and it will find it's way into your lock. The tighter the tolerance the more havoc this will cause. So they manufactur a certain amount of looseness in the lock so that it won't bind or jam due to a little dirt. It's this looseness that lets you slide a shim in and push the locking bolt back from the lock to disengage it. Usually this pin is held only by a spring, much like the catch on a door, and the shim pushes the bolt back allowing you to open the lock.

Better locks have made design changes to ensure the bolt will not move unless the key is inserted, as well as wards around the lock that make it difficult to squeeze a shim into place.

This is cool stuff, Mikabike. Do you know of any good web sites on how locks work? I'm trying to visualize the parts of the lock and coming up blank :)

On both my Kryptonite locks, the bolt is not held by a spring, so a shim would not be able to push it out of the way. The key needs to be turned to both lock and unlock the bolt.

In college I used a monster 1/2" chain. Look at that, and look at the dinky chain or cable on the 40 other bikes tied up, and guess which one the thief'll go for.

Now I'm parking at my office, where I have the only bike here. I just got a cable (1/2", but still) on the theory that if someone really wants to take it, it is gonna be gone. So the cable is just to deter casual theft. I got a cable instead of a chain because it's more convenient for me and I had to cut a cable the other day with bolt cutters and it was a PITA. Chains are easier to cut with bolt cutters.

http://www.lockpicking101.com has a great forum section. A lot of people were posting on there about those Kryptonite locks last year. I started my hobby reading the forums and talking to others. It's an unusual skill and I like the dexterity and mental site you have to have to get a lock open without a key. The first time you spring the lock it's like the first time you rode a bike by yourself. You will always remember it and it will make your heart pound.

Just make sure if you post questions about bypassing a lock, they know your talking about a lock you own. :)

I'm using a kryptonite u lock and a combo cable lock at the moment. It's taking kryptonite FOREVER to send me my replacement :(

But the combination of the locks seem to be serving me well :)

after much checking, it seems everyone was saying it was going to take 2-3 weeks to get an abus lock instock. I just decided to bid on a couple of locks on ebay (that were in canada) ended up with a Krpt EVO2000, light, strong and enough coverage to just replace my bike (and yes it's new). I was going to get the New York 3000 to compare weight and such but some idot bid it up higher then bicyclebuys.com sells it for....

IF you would like to see this lock broken in action I present to you the following http://thirdrate.com/misc/krypto.mov

Here's the same video, among others, available in a wider range of formats that I found from the original thread.

http://www.bikeforums.net/video/

it doesn't use the round keys :P, and i can't get your video's to work mikabike

Kryptonite and other bike lock brands sell at a huge markup- get a similar padlock and piece of chain from the hardware store for $10

Krypto NY U-Lock, and Krypto locking skewer set. It's nice not having to worry about the front wheel.

The April issue of UK's "Cycling Plus" magazine tested bike lock against the "force" methods commonly used by crooks, and then tested them against a portable, battery operated power tool of a type that crooks use on bike locks.

The "winner" was the 2005 Kryptonite New York 3000 U-lock. It could not be broken by force methods, and lasted more than ten minutes against power tools. The mid-price model from Abus lasted only 73 seconds against power tools. A "top of the line" Abus was not tested this time around.

The OnGuard Bulldog Mini" U-lock ($24 at REI.com) was as strong as the New York 3000 against manual attacks. No lock of any size, weight, or price outperformed the "Mini" against prying, breaking, and leverage attacks. The OnGuard Mini's superior performance is likely the result of its dual locking design that fully secures both ends of the shackle, and also due to the limited "open" space the Mini leaves for a crook to insert his tools.

Based on the "Cycling Plus" test results, I will use one (or two) OnGuard "mini" U-locks as my coffee shop lock, and combine the Mini with the 2005 Kryptonite New York 3000 lock for "heavy duty" midnight-in-a-rough-neighborhood high risk areas.

It is ironic that folks have been spending big bucks on bike locks that are almost too heavy to carry around and then Cycling Plus proves that the $24 OnGuard Bulldog Mini is just as strong as the "mega-locks" against the manual "force" attacks that are the stock-in-trade of about 99% of the crooks who steal bikes.


HOW TO LOCK YOUR BIKE CORRECTLY by Sheldon Brown:

www.sheldonbrown.com/lock-strategy.html

a thief wouldn't cut the cable, they'd bash the lock. Most have a cheap plastic housing that can be broken with a hammer with a few shots. They're really really fast to break. :(

and don't forget, we're out to save our bikes right. One can either be better than the next lock or take more time than thief x is willing to spend.

Thus my constant bit... cross lock.
You can cut a really good mini ulock with power tools in 5 minutes of really loud noise. With two locks they (hopefully) won't waste time.

I was "big" on "cross-locking" before I read the "Cycling Plus" test results. The test indicated that the $30 cable lock I was using for to secure my front wheel to the frame would last under twenty seconds against an experienced crook.

So, for SERIOUS protection, such as a "midnight movie", I will be using the New York 3000 for the rear wheel and frame (lasts forever against manual attacks, and ten minutes against power tools) and my OnGuard Mini to secure the front wheel to the frame (lasts forever against manual attacks, and maybe two minutes against power tools).

If I use the rack right in front of the theatre ticket office, I don't think some guy with power tools is going to spend 12 minutes or more noisily cutting away on my locks to steal my trashmo "movie night" bike.


HOW TO LOCK YOUR BIKE by Sheldon Brown:

www.sheldonbrown.com/lock-strategy.html

>>"Based on the "Cycling Plus" test results, I will use one (or two) OnGuard "mini" U-locks as my coffee shop lock, and the 2005 Kryptonite New York 3000 as my "heavy duty" midnight in a rough neighborhood lock."

Agreed... i have two OnGuard mini's (one for each bike.) At home both are active plus two cables. Next buy is a Krypto 3000 NYC. The OnGuards take 5 min each to cut, the NYC another 10.

Downside is the anchor point is ambiguous. A pair of cables to an old unbolted bike rack but through several bikes.

If you can't anchor, clutter.

Next question, how do you lock your bike to/ in your vehicle?


*

I've got a Kryptonite cable lock, with a key-not the lame circle key, a normal one. It's really light and thin but really tough and I love the key lock.

Alcyon, it does not matter which key a cable lock uses. An experienced crook can open your cable lock in just a few seconds. Some last under five seconds. Some U-locks last under ten seconds. The second most expensive U-lock sold by Kryptonite lasts less than two minutes against manual attacks. All locks are NOT equal. The quality gap between the best brand of bike locks sold in the USA, OnGuard, and every other brand sold in the USA is about as wide as the Grand Canyon.

If your bike is worth more than $20, get a first class U-lock, such as the OnGuard Bulldog Mini U-lock ($24 at REI). The "Cycling Plus" tests showed that the Bulldog defeats manual tools just as well as the $100 locks.

Attach the Bulldog around your rear wheel (just behind the seat tube). Use your cable lock to secure your front wheel to the frame and replace the quick release on the front wheel with an allen bolt.

At that point, you will have a security set-up that is "really tough".

Tubular locks have the potential to be much harder to pick than standard tumbler locks because they can use up to 12 pins vs 4-6 for most tumbler locks. Still a thief doesn't have the time to pick your lock. He's going to bolt cut or saw/dremel. Any lock that is reasonably built (no bic pen hacks etc) will do just as good on your bike as a high security one.

The only way someone is going to bother picking is if they have some privacy with your bike, or if they want to save the lock.

Mikabike, you seem to have some knowledge of "lock picking". Do you know whether a "quirk" in the new flat key locks from OnGuard and Kryptonite is a "flaw", or is part of some "anti-lockpick" design.

Inside the keyway of the new flat key bike locks, there is a stack of seven to ten thin metal plates with a rectangular hole in the center of each. If those ten holes are perfectly aligned, the key will seat down against the bottom plate, and when the key turns, the lock opens and closes.

However, if you should happen to turn the key BEFORE the key is seated against the bottom plate, the plates get misaligned. The key can no longer reach the bottom plate. You can put the key in and it may turn "like normal", but the lock does not respond. Folks might then try to force the key in, or force it to turn against the misaligned plates, and "snap" off half their key in the keyway.

After one of my new Kryptonite locks refused to open today, I shone a light inside, and saw that the top three plates were "cross-wise" to the bottom plates. I inserted the key just deep enough to turn those three plates back to where they were aligned with the other plates. Then the lock opened and closed normally.

So, is the rotating plates "feature" an essential protection against "lock picking", or just more stupidity from the bike lock industry?

I'm heading out to buy a new lock tomorrow, as I have finally gotten my shipping label to send the flawed krypto back. I was going to pick up the OnGaurd Mini that has been suggested, but I'm having second thoughts. Will it be big enough to go around my rear tire and then around the newer, thick, "Sin Curve" shaped bike racks that are popping up in cities?

I think you just described a 'warded' lock. Warded locks rely more on the shape of the key, than in precise cuts to align a set of pins. Most warded locks are not so much 'picked' as they are opened using a set of warded skeleton keys until the right one is found. You can also use a 'blank' inserted into the lock with a little bit of either candle wax, or soot from a candle and you rub it a little in the keyhole then see where the wax or soot was pushed away, then you cut down the key at those points until it fits. Not something you would do when trying to steal a bike though.

If you gave me the model number I could tell you more. Some pin and tumbler locks use a type of ward where the keyhole is cut at an angle to the pins (not perpendicular) which makes it harder to get a pick in as you are doing it at an angle to the pins.

alanbikehouston, to open my lock would take lockpicks, which:
1. No small-time thief (a bike thief is not big-time) would have or know how to use
2. Would need privacy to accomplish-bike racks are on the sidewalk, usually in broad daylight.

It is heavily armoured against cutting the lock cable itself, and even if it was attempted it would be an obvious (and loud) attempt to steal the bike, which would soon be stopped.