Forum: bicycles.stackexchange.com
Tags: <lock>
Title: U-lock stuck on a bike
Question: Some time ago, I stuck a U-lock on my bicycle for safe keeping, on the top tube below the seat. It's annoying when riding, and I'd like a way to remove it. I've lost the key some time ago, or I would have removed it that way. Preserving the lock is optional. What would you suggest?

Answers:
sents: text: I figured out a way to do it which was actually fairly easy.
text: This only worked because it was in my garage, trying to steal someone's bike like this would be crazy...
text: I took a hammer, and pounded on the bar.
text: The first thing that happened was the plastic broke away.
text: I kept pounding on it, until the lock just fell apart.
text: It took about a minute...
text: Note to self, don't buy a cheap lock next time...
answer_details: author: bicycles.stackexchange.com/users/998/PearsonArtPhoto
score: 8
sents: text: Ideas:
text: If you still have any of the original paperwork or packaging, look for a lock code/number, you might be able to order replacement keys.
text: Take it to a bike shop and ask.
text: They might have the right tools.
text: They likely do this every once in a while A machine shop is sure to have tools capable of doing this The local police department will have the tools or be able to refer you to somebody that does (they have to deal with removing abandoned bikes) An angle grinder, or other rotary cutting tool with a metal-cutting disk Hacksaw
text: (electric preferably.
text: Maybe an extra blade)
text: Big bolt cutters could you close the lock without the key?
text: Cut away any rubber and slide a shim made from an aluminum can down to release the latch Is it a cheaply made lock?
text: Might be able to just beat on it with a hammer until the latching mechanism falls apart a small car jack.
text: Most u-locks lock on one side and connect with an L on the other,
text: so bending the U open will release it For the tool based approaches, I would be very tempted to work out some way with a vice or two to hold the lock and bike steady, to minimize the chances of damaging the bike.
text: Thieves also use leverage based attacks, but I believe those risk damaging the bike.
text: And, of course, having proper proof that the bicycle is yours is a good idea, too, since all those attempts to defeat a lock look suspicious.
answer_details: author: bicycles.stackexchange.com/users/76/freiheit
score: 8
sents: text: A bit late now, but for the future it's worth knowing that it's possible to order a replacement key for most locks.
text: You'll need the serial number which is usually on the key or might be separately in the packaging
text: (it's not written on the lock itself for obvious reasons), so you need to make a note of that somewhere and keep it in a safe place.
answer_details: author: bicycles.stackexchange.com/users/1509/Tom77
score: 3
sents: text: We all lock ourselves out of something at some point.
text: At times it can be useful to respect friends 'with links to the criminal fraternity': cheaper with fewer questions asked when it comes to getting cars opened, D-locks removed and house windows opened. @Daniel
text: R Hicks See this: http://www.youtube.com/watch?v=0hsM88Wx8QQ Picked with a biro in a matter of seconds, not even 'Kryptonite'.
text: Some locks used to only come with half a dozen or so key variations so the security was assumed anyway.
text: With manufacturing outsourced to the Far East any brand, no matter how 'reputable' can have locks on sale that are not really that clever.
text: Sounds like you actually had a 'fake D-lock'.
text: Even the big makes foist these on the public, where the barrel is some bent tin inside a chunk of plastic.
text: Those can be opened with a moderately sizeable piece of wood.
text: Even if it was a real D-lock, have a look at how it would respond to the disc-cutter: http://www.youtube.com/watch?v=4XTYEcQAurs
text: What is that, 5 seconds?
answer_details: author: bicycles.stackexchange.com/users/1487/ʍǝɥʇɐɯ
score: 1
sents: text: This works with almost any type of lock:
text: Cost $0.
text: (optional) lubricate the lock with all purpose oil or graphite powder.
text: the lighter the oil the better.
text: get a similar key that goes in.
text: just find a friend with a ulock that still has the spare key.
text: get the spare key and file down the tallest teeth so that the key is a series of the lowest teeth insert key and keep applying pressure as if you were going to turn it to open the lock, and releasing the pressure.
text: keep doing this over and over during next step. get a small hammer and gently knock the key.
text: as if nailing it INTO the lock.
text: several times.
text: keep doing it.
text: does not loose your temper and apply force.
text: gently.
text: eventually, the key will turn!
text: the Technic is called Bump Key .
text: Bonus information: lock-picking is a nerd past time with several tournaments in the hacking community.
text: If you want to learn more look for the MIT guide to lock-picking .
text: Yes, that MIT.
answer_details: author: bicycles.stackexchange.com/users/1635/gcb
score: 1

Summary of the answers:
When a U-lock is attached to a bike and they key is lost, there are basically two options. The first is order a spare key or take it to a local bike shop. The second it to deal with the issue using tools, either yourself or with the help of a specialist or the police. If using the tools yourself, it is important to be careful not to damage the bike. Obviously, for the tool-based approach, proof that the bike was actually yours would be needed.
If you have the original paperwork, you may be able to order a replacement key, or get help at a local bike shop. Some lock types only come with a few variations, so a similar key may be able to be filed down to fit. Destructive options include hammering, levering or cutting with a hacksaw, angle grinder or bolt cutters. It can be good to carry proof of ownership though, to avoid looking suspicious.