Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I was trying to open the lock to use the bike, the key was jammed and I forced it so much it snapped so now part of the key is inside the lock and consequently the bike is locked and the whole lock is impossible to remove. What is the best procedure to follow?

share|improve this question
You'll probably need to open the lock by force. Please edit your question to indicate the type (ideally the model) of the lock. – sleske Mar 8 '14 at 22:16
If you don't have tools to take the lock off yourself (though it's surprisingly easy for most locks if you don't mind spending a little time), just call a locksmith -- he'll use bolt cutters or an angle grinder and have it off in a few seconds. – Johnny Mar 9 '14 at 1:15
I don't know what locksmiths charge where the OP is, but I would guess they're like most skilled craftsmen and a service call isn't cheap. In most of the US I would expect to pay at least $50 just for the guy to show up. In a major city I would expect double or even triple that. Anything complicated would be on top of that. But I guarantee I could cut any bike lock for less than $50. I might have to buy a $40 tool, but that's still less than the cheapest locksmith. – Carey Gregory Mar 9 '14 at 6:16
On a bike tour a couple of years back one rider had a lock jam. I borrowed bolt cutters from the mechanic and had it off in probably less than 60 seconds. (But how well bolt cutters work depends whether the shackle is hardened or not.) A battery powered angle grinder is pretty much a sure bet. And a locksmith may be able to remove the broken-off key, if you have a spare key. – Daniel R Hicks Mar 9 '14 at 12:55
Regarding questions: you'll be amazed how few comments you get when hacking away at your bike, trying to remove a lock. Showing the broken-off key was enough to "let me off the hook". But perhaps make sure you have a photograph of you and your bike in case someone (or a police officer) is persistent. – Reinout van Rees Mar 11 '14 at 11:09

If this is the cable or chain lock use bolt cutter. If it's a D-lock (U-lock) you have to use a hacksaw.

share|improve this answer

If part of the key is in the lock, your best bet is to save the key stub and use it to turn the lock. The trick is to get the broken off piece in the right position – not too far out and not too far in – and turn it. It'll work like a regular key, and I've opened a few locks with broken off keys this way. Instead of the stub, a screwdriver might also do the trick.

If the lock mechanism is rusty, try spraying some WD-40 on it and let it sit overnight. If it's very rusty, repeat the exercise one more time.

If you pushed the broken off piece in too far, it will not turn. In that case, you could try with a dab of super glue on the key stub, press it onto the fragment, let it harden and pull it out a bit.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.