walking sux

July 30, 2006 8:05 PM

How do I get my bike lock open?

My bike lock is stuck. It's a U-lock, holding my bike (frame) to a post on my house. Sawing through my bike frame or dismantling the house are not options for me, so I need to get the lock open. I think the inside mechanism is rusted; the bike has been sitting out in the weather, where it is now, since last fall. The key fits into the slot and turns slightly, but not enough to open the lock. I've tried soaking it in Liquid Wrench overnight and tapping it with a hammer to loosen up the insides. This has not worked. What else should I try? If I have to cut it off, what's the best way to do this? I don't have any good cutting tools on hand and I can't afford to buy anything major.

posted by thirteenkiller to Home & Garden (26 answers total)

Try a car jack. It's meant to work quite well.
posted by sien at 8:15 PM on July 30, 2006

I'll second using a carjack; it's the professional bike thief's weapon of choice. Some thieves recommend a Volvo carjack as it is a small enough jack to fit inside the U-bolt.
posted by Blazecock Pileon at 8:17 PM on July 30, 2006

I don't know if this will be what's happened in your case, but--

I had one of those U-Locks fail, also after sitting in the weather awhile. It turns out there were some pins around the inside of the O-shape that the key fit into and one had come loose. The pin wouldn't go back into place, but after knocking the lock around a bit it fell out and then the key would go back in and turn (not easily, but it did open).
posted by Tuwa at 8:18 PM on July 30, 2006

As others have suggested, a car jack will be quickest. However, if you're going to try cutting, I recommend a hacksaw with a good fine-tooth blade (I'd probably use a 24-32 TPI bi-metal blade).
posted by RichardP at 8:19 PM on July 30, 2006

Is it the old-school round key style? If so, , you should have no problem opening it.
posted by serazin at 8:25 PM on July 30, 2006 [1 favorite]

If you use a car jack, note that when it finally gives way it'll probably be violent, with pieces flying off rather rapidly. Don't stand in line with the direction of force being applied by the jack.

You might consider using WD-40 on it. Spray it really good; use the straw to spray it inside, and then let it rest an hour. Then try your key again.
posted by Steven C. Den Beste at 8:38 PM on July 30, 2006

Serazin, the problem is that the lock is rusted. He has the key; it doesn't work.
posted by Steven C. Den Beste at 8:38 PM on July 30, 2006

If you call the locksmith, they will come over with a heavy-duty dremel, and use a cut-off wheel to cut the lock off in about three minutes. If you can borrow a dremel, you can do it for the price of a cut-off bit. When a friend had a locksmith do it, they charged $65 for chopping off a Kryptonite with the broken key.
posted by rajbot at 8:40 PM on July 30, 2006

Oh, duh. My reading comprehention skills decrease dramatically after the coffee wears off around 2pm.
posted by serazin at 8:55 PM on July 30, 2006

Me too. I didn't notice that he'd already tried a penetrator oil.
posted by Steven C. Den Beste at 9:09 PM on July 30, 2006

Last time this happened to me, I rented a power cutter from Home Depot for $10. Wear goggles -- flying sparks can cause serious eye damage.
posted by randomstriker at 9:12 PM on July 30, 2006

You can open a lot of U-locks with a simple ballpoint pen. Do a google/Youtube search for it--I didn't because I'm very lazy.
posted by zardoz at 9:41 PM on July 30, 2006

Too lazy to read both the question and the other answers, clearly.
posted by solid-one-love at 9:49 PM on July 30, 2006

The other way that'd be interesting to try would be to get some liquid nitrogen and tap the lock and have it break that way.

If you know someone who works at a lab or is sciency in some way this may be possible.

And if you do do this be really sure to take proper precautions.

Crow bars may also be a viable option. If you have AAA you could try calling them too.
posted by sien at 10:13 PM on July 30, 2006

The liquid nitrogen method just doesn't work, at least not easily. It's just too difficult to dip exactly the right part of the lock in the LN2 without dumping it all over the place or freezing one of your fingers off -- and even then, cold metal isn't THAT brittle. Jacking the lock open, or cutting through it, are much more realistic options.
posted by xil at 10:40 PM on July 30, 2006

I've been wondering whether a can of electronic component cooler, or dusting gas turned upside down, could accomplish the same thing as liquid nitrogen. I'd try it just for the heck of it if I had a stuck bike lock.
posted by evil holiday magic at 10:41 PM on July 30, 2006

I had a similar problem with an OnGuard U-Lock a few months back. Although I was using it on a daily basis, it just wouldn't open one day.

I contacted the company and they were incredibly helpful. Here is a selection from their response,

"The binding happens when the pin that holds the tumblers together, and should move freely when the tumblers align, stops moving freely and binds up against the inner surface of the locking mechanism. This corresponds with about 90-degrees of rotation of the key. You would experience a similar problem if you inserted a key into the cylinder that did not match the tumblers and tried to open it.

Although we do not recommend that users rely on the following method, we have found a way to unlock most locks that are binding as a result of the above-described problem. The procedure is as follows:
1) insert the key in fully into the cylinder
2) turn it 90-degrees, right before the point where the key would normally start binding.
3) with the key in this position, sharply tap the lock with a firm object (we've used another lock, a small hammer, or similar object) along the length of the crossbar.
4) as you are tapping the lock, continue turning the key.

We should note that this method had not worked on all locks, but it has been helpful in getting users out of binds. We should also note that you should NOT FORCE THE KEY. Excessive force used to turn the key may result in bending or breaking the key or damaging the locking cylinder."

I realize that you tried, "tapping it with a hammer to loosen up the insides," but this worked like a charm for me. Perhaps it can help you in some way.
posted by hooves at 10:53 PM on July 30, 2006

Like the 'peakoil' tag. A locksmith should be able to take care of this for you - but it might be expensive. Do you have any marketable skills you could barter with the locksmith?
posted by altolinguistic at 1:18 AM on July 31, 2006

Forget supercooling it, try super-heating it with thermite.
posted by Paris Hilton at 3:15 AM on July 31, 2006

Borrow an angle grinder from a neighbor.
posted by flabdablet at 4:39 AM on July 31, 2006

i agree with flabdablet - find someone with an angle grinder. I've seen a lock removed with one in about 30 seconds.

And actually, the person who did the grinding was the owner of a local bike shop. I'm not sure if it's usual for a bike shop to offer these kinds of services, but it's worth looking into.
posted by chrisege at 5:42 AM on July 31, 2006

Angle grinder is the way to go. Wear face protection, or at least eyeguards, and gloves. It will take less than a minute to cut through a standard u lock. If you can get someone who knows what they're doing to do it, that would be better, but an angle grinder is the perfect tool for the job.
posted by louigi at 7:27 AM on July 31, 2006

Angle grinder, dremel, or car jack, in that order.

Hacksaw? Have any of you people ever actually tried to cut hardened steel with a hacksaw? Hah-hah-hah, it laughs at you.
posted by jellicle at 7:56 AM on July 31, 2006

Angle grinder, si - hacksaw, no. (Unless you've got a diamond-encrusted blade in the hacksaw.) The shackle is hardened; a regular hacksaw blade will go dull before it starts to cut.

You could try some padlock shims, if they exist in the right size. Or make your own from a beer can.
posted by Kirth Gerson at 8:16 AM on July 31, 2006

An oxy-acetylene torch will do quite nicely too. Just make sure to peel off the plastic first.
posted by Lazlo Hollyfeld at 9:15 AM on July 31, 2006

Angle grinder.

I used to live in a big student co-op with a gigantic bike rack. Every year or so we'd leave notes on the bikes ("please remove this if you own this bike"), and after a couple of months (and much reminding) we'd grab some goggles and the angle grinder and start redistributing bikes. It'd take about 4 minutes per lock, even good u-locks.

You can probably rent one for fairly cheap from a local machine shop. Remember to use goggles. Can't stress that enough. The coolness factor of an eyepatch does not cancel out the loss of depth perception, especially if you're planning to ride that bike again.
posted by Coda at 11:57 AM on July 31, 2006