robbat2: (Default)
robbat2 ([personal profile] robbat2) wrote2008-08-03 11:10 pm
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Thoughts on bike locks

Having my bike stolen has made me wonder about locks more. Defeating most forms of bike locks are trivially easy with some lateral thinking.

This was my lock:

Lock properties and attacks against
key-based
bumpkey (given a suitable blank or other key of same style), pick the lock, drill or freeze the lock (either LN2 or just adding in warm water on a day that's below freezing)
combination-based
guess or shoulder-surf the combination
Cable/Chain
Large bolt cutters, wire cutters or hacksaw
U-Lock/D-Lock
Use a jack inside the arms to apply outward force

Any other bicycle lock types or different attacks that you can think of? Any way to effectively defeat one of more of the above attacks? From a security perspective, we need to consider not only the permitted attacks, but all possible attacks.

In my case, they either defeated my combination (probably by shoulder-surfing), or just used some form of cutting attack. Since the lock wasn't left behind, I suspect the former more than the latter.

[identity profile] paris-of-priam.livejournal.com 2008-08-04 07:35 am (UTC)(link)
In my experience nine out of ten bike thieves use bolt cutters, which makes anything with a cable or a chain easy to cut through. The type of lock (combination or key) is irrelevant. In my experience the best lock to use is a U-Lock because it's pretty hard to cut off with a bolt cutter, and a hack saw takes too long. They want to be in and out in five seconds. When you use a pair of bolt cutters on a chain or cable lock, you're away with the bike in five seconds. If you encounter a U-Lock, you probably just move on to the next bike with a cable lock UNLESS the bike is VERY valuable. Like one of those $5000 jobs, in which case I'd recommend not leaving it outside. :)

I had two bikes stolen. First one I locked up with a chain lock, and they stole it. Second one I locked up with a cable lock, and they stole it. Third time, I got a U-Lock, locked it up in the same place and it was never stolen. :)

Also, remember to lock the U-lock through both the frame and the front wheel. I've seen people lock their front wheel to the bike rack, and the thieves just unscrew the bike, take it, and leave the front wheel behind. I've also seen the reverse, where they steal the front wheel when the bike frame is chained up. (Probably the same people, who need front wheels for all the bikes they stole by unscrewing the front wheel.)

Also, for some freakish reason, bike thieves will steal bike seats and handle bars sometimes, if the frame and front wheel are locked. I'm guessing they must be pretty desprate at that point.

I had a friend once who had a $500 car, and a $3000 bike. She'd never leave the bike outside. She always brought it into the lab with her. Can't say I blame her.

But like I said, my one and only practical solution, which didn't take too long, was just to use a U-Lock, not have a bike that was worth more than about $150, and run the U-Lock through both the frame and the front wheel. I never bothered to remove the lights, handlebars or seat. I just took my chances.

[identity profile] cupcakecalamity.livejournal.com 2008-08-04 03:30 pm (UTC)(link)
Any non-cable or chain. A u-lock is your best bet.
http://www.kryptonitelock.com/
These are ok.

But you should just never leave your bike alone in this city, even locked up. Any number of parts can be removed quickly, and most people won't stop to ask what they're doing, because they assume they bike is theirs anyway (I have done this).

The best thing you can do is to get two bikes, a nice one and a crap one that can be replaced for $50. Use your crap bike on days where you'll be unable to watch it for extended periods of time.


...or bring the expensive one and cover it in lye WAHAHAHAAAAAAAAAA

[identity profile] amaena.livejournal.com 2008-08-04 07:29 pm (UTC)(link)
From a security perspective, we need to consider not only the permitted attacks, but all possible attacks.

I think I've heard that before, quite recently. Sad about the bike! But amusing to see the security mantra applied elsewhere.
(deleted comment) (Show 4 comments)

[identity profile] sciencequeen.livejournal.com 2008-08-04 09:30 pm (UTC)(link)
I use a U-lock and I haven't had my bike stolen, but I've only had my bike since April...

Mind you, I've locked it downtown and at Production Way sky train, and I figure all sky train stations are sketchy for that activity.

[identity profile] tupni.livejournal.com 2008-08-07 05:55 pm (UTC)(link)
Chains do not work. They are far too easy to defeat. The same goes for cables. I have a set of bolt cutters with 14inch handles, they could fit inside a jacket, and they could cut most cables out there. Ulocks are much safer. Yes, you can jack them, but jacks are a lot harder to transport about, and you have to be able to wangle the jack between the u and the lock. Don't get a bic-pickable lock, get a real key. Kryptonite sells one - New York Fahgettaboudit® U-lock. They are expensive, but still cost less than $100.00, and unless the bike thief carries nitro around with him/her/it, pretty much will prevent the theft.

[identity profile] swissreplicator.com (from livejournal.com) 2009-06-17 12:16 pm (UTC)(link)
Sadly, thereis`nt any more better protect for bike except this locks (

[identity profile] gustavolacerda.livejournal.com 2010-03-20 08:29 am (UTC)(link)
I will add my voice to the choir advocating U-locks.

When I moved to Amsterdam, my first bike got stolen within 24h. Since then I've only been using high-quality U-locks (>$30), and it never failed me. I have evidence of a failed attempt in Pittsburgh, in front of my house.