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My bike key is broken off inside the lock, I already remove the key from the lock but I have no backup key to unlock it.

It is a very ordinary key, just like this:

enter image description here

Is there any way to unlock my bike? Will the brick or a saw be helpful?


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Is it a cable lock like in the image. If so, bolt cutters. You'll be surprised and dismayed to see how easily you can cut a cable lock with a set of bolt cutters (maybe enough to invest in a better quality lock?) – WTHarper Nov 27 '12 at 17:17
@WTHarper maybe make that an answer instead of a comment? Then your answer can be voted up -- you get reputation, and this question no longer shows up on the "unanswered" page. – joseph_morris Nov 27 '12 at 18:01
Yeah, if you're not trying to save the lock, bolt cutters are the best choice -- will cut through that cable in about 30 seconds. You can buy a pair cheaply at places like Harbor Freight in the US, or maybe rent a pair at a tool rental shop. And don't be too worried about using them "in public", since tests have shown that people just ignore bike thieves 90% of the time. (But do make sure you have your ID on you.) But if you want to save the lock you need to pick it or get a locksmith to do so. Not rocket science, for a standard pin tumbler lock. A locksmith can then cut you a new key. – Daniel R Hicks Nov 27 '12 at 19:19
And as Benzo said in a deleted answer, you can more slowly cut through the cable with ordinary wire cutters, a few strands at a time. This might take 15 minutes or so, though, and will leave you with bleeding knuckles. – Daniel R Hicks Nov 27 '12 at 19:21
Unless it's a very expensive lock, the locksmith would probably cost you more than a new lock. – Kibbee Nov 27 '12 at 19:38
up vote 11 down vote accepted

Is it a cable lock like in the image? If so, bolt cutters. You'll be surprised and dismayed to see how easily you can cut a cable lock with a set of bolt cutters (maybe enough to invest in a better quality lock?) They're cheap, easy to find, and will get through most wire cable and some chain (depending on hardness.) They're also the go-to for most bike thieves, so don't be overly conspicuous about using them.

Bolt Cutters

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Yeah, if it's a cheap lock, just about any tool will do. Bolt cutters, hacksaw, Dremel with a cutting disc, hammer (to the locking mechanism), vice grips, wire ships (for cable locks). You can be creative. – Kibbee Nov 27 '12 at 18:33
A hatchet, a sharp rock, a pry bar...the list goes on, unfortunately. – WTHarper Nov 27 '12 at 19:26
IMO a hacksaw blade, warped in a newspaper for a handle, is the cheapest solution. Guaranteed to work in under a minute. – Vorac Nov 30 '12 at 9:06

If you own a hacksaw but don't own bolt cutters, it only takes a few minutes to cut through the cable with a hacksaw. Just grip the cable with a pair of pliers, then use the hacksaw to cut the cable near the pliers - the hacksaw cuts through the individual cable strands quickly. When I lost my cable lock key, it took me less than 5 minutes to cut off my 3/8" cable lock with a hacksaw. Would probably have taken less time if I had someone else to hold the pliers.

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