I was browsing Kickstarter the other day and came across a really neat, lightweight titanium bike lock.
In a video, they attack it with a hacksaw, an angle grinder, and a bolt cutter, and it survived better than a generic steel U-lock in those tests.
Are there any attacks that a thin titanium bar would be more susceptible to? Bolt-cutting from the Y axis? Compressed air freezing? Back-and-forth bending? Twisting? Chemical reactivity or susceptibility to strong bases/acids?
I don’t think a bolt cutter could open wide enough to bite through the thing, width-wise.
It takes about three times longer to hacksaw through it compared to a Kryptonite U lock, and it costs about three times more. I think I’d probably be three times more pissed-off when my bike still manages to get stolen anyway.
IIRC titanium is vulnerable to corrosion from chlorine; the titanium skin of the SR-71 Blackbird suffered damage from chlorinated water and markers with chlorine in the ink (draw a square on the skin, the square will fall off the plane). I’m not sure if that has any significant effect on something under less stress than a supersonic plane though.
Titanium is pretty brittle… how about a good smack from a small sledge?
If I had a bike lock where the lock part wasn’t used to attach the rest of it to the bike, I’d lose the lock part in about two days, dorky cargo shorts or no.
I feel like it would be susceptible to twisting. A couple of sizable pipe wrenches, I think you could corkscrew it, and weaken it enough to fail.
Does freezing and wacking it work?
I’ll bet the weakest point is the lock cylinder, being stainless steel rather than ti.
There may be conditions under which titanium is susceptible to attack by chlorinated chemicals, but in general it’s pretty corrosion resistant to it. Titanium piping and vessels are widely used to contain chlorine and chlorine dioxide in aqueous solutions. Dry chlorine gas is different, but dangerous to handle, and hard to come by on the street.
Sulfuric acid is very good at attacking titanium as long as it hasn’t been passivated by sodium chlorate.
Looking at the lock, and to answer the question, I’d say a nibbler type tool would be the smallest/easiest way to cut it. Like a scissors made to cut sheet metal, with short cutting blades and very high leverage.
As per titanium, and just cause it is a pet peeve… a lot of folks randomly mix up titanium and tungsten or tungsten carbide. Titanium is not super-strong or hard, it is pretty much equivalent to steel as far as those characteristics go. It is just way lighter and more corrosion resistant. Tungsten carbide and titanium jewelry rings are both available. The really hard, heavy, and brittle ones are tungsten carbide. Titanium rings are silvery white, and corrosion resistant, but not hard/scratchproof or unsawable.
The weakest part by far is the frame of your bike. If someone really wants the bike, they’ll just cut through the frame and weld it up later.
Have you ever heard of anyone actually doing that? I can’t imagine a casual thief going to that much trouble. A good steel frame would probably be ruined – the heat from welding would mess up the metal’s temper, and to get the frame past the lock would mean either making two cuts to get a big enough gap or twisting something a fair amount, either of which would almost certainly screw up the frame’s geometry. Who’s going to want to ride, or buy, a bike with a damaged frame?
I think the Pipe twisting it would be a good start.
the reason the grinder/saw had trouble was
So, twist with pipe good grinder with a cut off wheel, less flex on the bow, and cuts quicker.