Does anyone have any experiences with accidentally being able to open other locks with their own key?

I read online that cheaper U-locks (and expensive Kryptonites) have this issue ... one key can open other locks. And no the owner did not request that these locks be keyed alike!

If there are 5 pins and either an 'on' or an 'off' for each, then there are only so many combinations possible. There WILL be repeats, and a lot of them. Same is true for old-style car keys. Your keys will open about 1 in 25 of every similar car (GM, Ford, etc,) in the mall's parking lot. The situation is better now that the mfgs put computer chips on the keys, too.

Years ago one used to see a story from time to time about someone actually driving away from a mall or other large parking lot in the wrong car. Hadn't thought about bike locks, but I know office cabinets and desks tend to have only three or four keys that fit much of the product line.

Believe the Internet Eh?

Guess you are regretting that $9 lock?


My Ring lock bike buy 08, was requiring the serial number on the key be stated to get a Spare ..
That came in the Post from NL.. Used Bike Buy the key was Bent in the lock (It's in there to ride , removed to Lock)

No Blanks are even of that type in US Locksmiths ..

A friend of mine recently discovered that his house key opens the main door to another friend's apartment building....

With bike locks as with many things, you get what you pay for. And in this case, "pay" means not only money but also weight. Better locks are generally heavier as well as more expensive.

For what it's worth, even if the lock's construction is such that there are only 25 possible key types, it's likely that if a thief is determined enough to try carrying around all the keys it would take to be able to open, say, the four or five most common models with relatively few key types, that thief is more likely to have quicker ways of stealing your bike than to stand there trying keys.

It doesn't mean it's impossible that some opportunist will try their key in your lock, find that it works, and take your bike. But even with a lock like that, the matching key thing doesn't seem like the most likely method of taking your bike. If you're locking up someplace where you think you need to worry about that, you probably should be using a better lock overall anyway.

Oh yeah, and then there was that time some years ago when all of a sudden the whole internet realized you could open a whole lot of expensive Kryptonite locks with a Bic pen. The day I saw that, I tried it on my lock and opened it in under 20 seconds, just by sticking the body of the pen in there and wiggling it around. Went to my LBS and tried it on locks on the shelf and did the same thing.

Kryptonite changed their key design after that.

Don't worry about the duplicate keys, a good angle grinder can cut any u-lock in less than a minute. Google it. The take away is don't lock an expensive bike in a high theft area. If a professional bike thief wants it, then it is not safe no matter what lock you use.