You know, I've toyed with this idea myself, but unfortunately, it's against the law to set a booby trap for thieves. The thief would attempt to steal your bike, the booby trap would go off, the thief would be injured, and would have grounds to sue you, or more likely, the lock manufacturer. Sad, but true.

Logic would say this was a 18-24 v cordless cutoff tool using a reinforced diamond abrasive disc. A disc guard could have masked any spark shower. Like this: http://www.all-cordless.com/ma18lxtlicot.html

No doubt current off-the-shelf tools will cut through most metals; it's the exotic metals I wonder about.


"...But your honor, who said anything about a booby trap? Most bike lock tubing is reinforced with mustard gas; it's common practice in the industry." :)

:lol:

Titanium's not that bad. I've even cut it with hand tools, a pipe cutter and a hacksaw. It's softer than steel unless it becomes work hardened. You've just got to be aggressive with it, and not try to make a nice gradual cut, or it will unsharpen your pipe cutter blade. (been there, replaced that blade) But what's really fun is grinding titanium! Once you've seen the shower of sparks thrown off by titanium, you'll never call anything else white again. Just don't breath the ground titanium dust, you'll regret it if you do.
Stellite would cost a fortune to make into something like a lock. I've heard that some of the alloys can technically be cut with carbide tooling, but that doesn't last long. It's generally machined with abrasive surfacing tools. Takes forever. And then there's the usual issue with really hard metals: Whack a good cutting tool with a hammer, and it will splinter. Hardness involves some balance between brittleness and softness. Cutting tools fall much further over on the brittle end of the spectrum than is practical for a lock. A lock as uncuttable/brittle as a drill bit would suffer the same fate under a hammer.

Stainless might be a good compromise, even good old 304. It's ductile enough to form and although it's a pain to cut it's not prohibitive. But the thermal conductivity is so low that it'll heat up locally and work harden in an instant if you make a mistake cutting it. Try drilling a 1/4" hole in 12-18 gauge stainless at high speed and low pressure and you'll see what I mean. You'll get one severely dull bit and a blue dimple in the sheet metal that's nearly impervious to most drills. Abrasive tooling isn't exactly effective, because the heat produced means that the abrasive is always scraping through hardened material.
Maybe if a stainless u-lock had multiple small cavities running through its length, those would serve to collect work-hardened chips, which along with the multistep cut would do terrible things to a cutting tool edge. Not to mention, if someone went after it with an abrasive cutoff tool, the multiple heat-hardened sharp edges formed by the cavities in the stainless would cut down the abrasive a lot faster than the abrasive cut the lock. Empty spaces would save some weight as well, which would be important since stainless weighs a fair bit more than steel.
But at the price necessary to pay for additional design, material, labor, and tooling to deal with stainless, it would be tough to sell enough locks to pay off the original investment. If I get really bored someday and I'm feeling a little masochistic, I might make up a stainless U for my New York lock. But probably not, stainless is a complete headache to work with, insanely heavy, and if someone's got a sawzall they'll be able to get through any bike rack in under a minute anyway. Such is life.

The plastic housing around the lock needs to be made of a material that turns into the foulest, stickiest, tool marring, hand staining, of near impossible to wash off gunk, when subjected to pressure and heat. Slows em down a bit, and gives the thief a kind of a dye bomb to have to deal with too.

That would do the trick!

Stainless is a great answer. Some people would pay more for an even harder to cut lock. It might be too heavy for most cyclists. But maybe stainless in the smaller sizes.

Ack. You're killing me, KnhoJ.
What if the lock itself was scored like a file and coated with, say, diamond dust? Would such a design quickly dull sawzall blades and/or grinding discs?


I like this idea a lot.

Yes, it is tough to carry Chuck Norris around in a messenger bag. Very tough.

If two Krypto U-locks are too cumbersome to carry around, I might suggest leaving a padded Fahgettaboudit steel chain at the bike rack or in your office. Fasten the chain together with a triple chrome plated, freon spray proof, rockwell hardened German ABUS Granit padlock (Used for Harley Davidsons). Properly running the 5 ft chain through your frame and both wheels, will require the thug to resort to torch cutting the bike rack. A hacksawed frame doesn't fetch much on e-bay or craigslist these days.

Thank you for posting this, I couldn't find any way to do this. I realise its not fantastic quality, and I am sure there are those that are still skeptical.

Thanks again.

Jon

I never said I was perfect! I couldn't get the lock to fit around the bike and totally fill the void as the bike rack has a much larger than normal diameter which made it very difficult to lock the bike against, the Cronus also has an 'odd' geometry which seemed to make it harder.

In regard to CCTV angle and the pillar, it not seem obvious, but when I was locking it up a cursory glance seemed to show that the camera had a good view. Next time, I will be more diligent - in all respects.

I would also note that while the video is not detailed, my main aim (assuming that people actually believe my version of events) was to show that from walk up to ride away really was <2 mins. It does assume that you believe my version of events, and that the bike was locked by me some 2 hours previously - which it was.


Thanks

Jon

Wow@the video

I wonder if you had parked on the other side of the column if he would have gotten someone elses bike instead. It seems he had a pick of a number of bikes but that one was most obscured from the video camera.

This was the kind of constructive discussion I was hoping to develop. When I read this I started to wonder about a more 'layered' approach to the material construction of the lock. With a metal laminate construction, could you make the outside less to vulnerable to one type of attack, then an inner core that was a polar opposite, and added the idea above using some form of coating that would create a challenge with heat/friction.

Thanks

Jon

I will be revising all my strategies when I replace the bike. I just spoke to the insurance company this morning and they have processed the claim and I should have the cash next week all being well.

Thanks

Jon

Got back from Vegas last night, sorry for the rash of posts. I also forgot until today that I had pinhead skewers fitted, to prevent wheel/seatpost theft ... oh the irony.

Jon

Jon, I'm glad to hear your insurance company is taking care of it. :)

Here's an idea I came up with last night to improve u-locks...

I was thinking about a GPS transmitter (use in Wildlife research) inside the frame of the bike. If they can attach one to a baby seal and works in the Arctic, they can make one work for bikes.

INSIDE the frame at a discreet location. Charging can be done through induction (If you have a electric toothbrush). Nothing is ever fool proof, but that's the solution to your concern.

Can you not bring the bike inside with you? I used to bring mine indoors and park it in a computer closet rather than leave it out - even on a rack.

A bike thief today is what a horse thief was 150 years ago. And they should be afforded the same sentence, IMO.