U-Lock Saw

May 23, 2008 2:52 PM

How do I liberate my bike from a U-lock?

A few weeks ago, I locked my bike in front of my gym and went inside. I lost the key, somehow, and after contacting Kryptonite customer service for help, it seems as if I don't have the requisite paperwork to get them to make me a new key. Local locksmiths are asking somewhere in the neighborhood of $100 to come saw the lock off... I do, however, have access to lots of power tools, and am wondering if anyone has had to saw through a U-lock before and could offer advice. It's this lock.

By the way, I fully recognize that this looks pretty sketchy, but all I can do is assure you that it's my bike, it's been sitting in front of my gym for weeks, and well, the bike really isn't worth that much to begin with...

Thanks!

posted by jtajta to sports, hobbies, & recreation (22 answers total)

There are two common ways to crack that type of lock.
Thieves tend to use a small car scissor jack to bust open the lock. Simply place it inside the two parallel bars of the U and start opening the jack.
The second approach works if your lock was one that has a round key barrel. Using a cheap Bic-style pen, you can pop open that lock. There are videos on YouTube that will demonstrate this technique.

Good luck!
posted by browse at 2:58 PM on May 23, 2008 [1 favorite]

My reciprocating saw would be my 1st choice if I were in your shoes.
posted by buggzzee23 at 2:59 PM on May 23, 2008

Is it old enough to use a Bic pen on?

Some years ago I lost a bike lock key and campus security came by and removed the lock pretty easily with a small angle grinder type thing.

Other techniques I have heard of, but not seen done, are to put a car jack into the lock and bend it apart; and to douse it in LN2 and whack it with a hammer.
posted by hattifattener at 3:02 PM on May 23, 2008

I'd think you would be able to drill out the lock pretty easily with a cordless drill and a diamond-coated bit (they're like, a dollar more expensive than a steel bit). There's really not much advice - it's a pretty cheap lock. If you have it, a Sawsall or a reciprocating, which is like an electric turkey carver for the home craftsman.
posted by muddgirl at 3:02 PM on May 23, 2008

How old is your lock? If it's more than 3 or 4 years old, you might be able to open it with a pen.
posted by xotis at 3:04 PM on May 23, 2008

An acquaintance with an angle grinder made very short work of a heavy-duty bike lock for me when my key broke off in the jammed lock. It wasn't a U-lock, but the part he cut through was as thick and reinforced as a U-lock.
posted by Your Time Machine Sucks at 3:04 PM on May 23, 2008

Thanks for all the answers - very quick response, too. Anyway, the bic pen trick won't work, but I'll get a grinder out there and see what happens.... Keep the ideas coming!
posted by jtajta at 3:08 PM on May 23, 2008

Just a thought... if the gym's in a mall or shopping center, you many want to contact the local security patrol (or even police) before you start doing something that looks so obviously criminal.

"I swear officer, this is MY bike. Really. No please, put the handcuffs away." is a conversation you want to avoid.
posted by gnutron at 3:20 PM on May 23, 2008

you *don't* want to have, that is.
posted by gnutron at 3:21 PM on May 23, 2008

Bolt cutters?
posted by Thorzdad at 3:36 PM on May 23, 2008

Bolt cutters worked for me when my u-lock jammed. Cutting it off the bike rack in the middle of a busy campus in broad daylight didn't really seem to raise the concern of any passers-by.
posted by moift at 3:47 PM on May 23, 2008

A few years ago a thief with a hammer and screwdriver munged the U-lock on my then-girlfriend's bike. The carjack technique didn't work (kept slipping off), and in the end we borrowed a very serious pair of boltcutters that did the trick.
posted by Hogshead at 3:59 PM on May 23, 2008

If you know someone with a cutting torch (oxy-acetylene), that'll slice through the lock in a few seconds. Otherwise, an angle grinder will work fine. The car jack is sometimes good, but that depends on how you locked up the bike -- there needs to be enough space in there for the jack to sit, and not all jacks have the right dimensions for a good fit.

My guess is that no matter how much noise or sparks you make, no one will say anything or call the police.
posted by Forktine at 4:05 PM on May 23, 2008

When this happened to me in college, the campus police cut it off with something that looked to me like the cutting torch Forktine mentioned. (They did it after I showed them a receipt, not just cause I said it was mine.)
posted by Airhen at 4:12 PM on May 23, 2008

This video shows a guy trying various methods of stealing (his own) bike in NYC. An angle grinder does make an appearance.
posted by dubold at 4:14 PM on May 23, 2008

The advice above sounds great. When I lost the key to my bike, which was parked on one of the busiest intersections in town, I stole it without a problem. I caught a bus into town with a hacksaw, walked up to my bike, and just started sawing away. Not a single person stopped me, or even questioned me about it.

So yeah, maybe clear it with security first, but don't be surprised if the average passerby doesn't care.
posted by twirlypen at 4:27 PM on May 23, 2008

2nding scissor jack. I've opened a U-lock with the OEM jack from an 80's era Subaru, just by putting the jack in place such that it was pushing the two parallel bars in the U apart and cranking away. Took all of five minutes.
posted by toxic at 4:35 PM on May 23, 2008

jtajta writes "I'll get a grinder out there and see what happens"

Install a thin kerf cut off disk in the angle grinder and you can cut through it in no time (like a warm knife through butter). The standard thick grinding disk involves a lot more work.
posted by Mitheral at 5:14 PM on May 23, 2008

Yeah, an angle grinder or circular saw with an abrasive metal cutting wheel is the right tool for this job.
posted by flabdablet at 9:40 PM on May 23, 2008

Another vote for angle grinder. Has worked many times for me.

Don't use a jack -- if something slips or snaps you could have flying pieces of metal.
posted by randomstriker at 11:17 PM on May 23, 2008

Nthing the angle grinder, if only because they're so damned fun to use. Such a satisfying tool. Why wouldn't you, given the opportunity?
posted by mumkin at 12:01 AM on May 24, 2008

Dunno if I'd use a reciprocating saw - they've not much good on truly hard &/or tempered materials. As everyone else has said, use a grinder with a diamond cutoff disc. Alternately, if you don't have power handy, use a hacksaw with a tungsten carbide or diamond grit blade.

A locksmith will likely use a diamond cutting wire (aka angel wire), either in a hacksaw frame or just held by hand. If you're lucky, your local locksmith will sell you an old worn one for a few bucks. We used to buy old ones for work from the local locksmith, and they'd quite happily cut through the tempered shackles of high-security padlocks in under a minute.
posted by Pinback at 6:04 PM on May 24, 2008