The best Dlock 2013, the Abus Extreme 59?
http://www.urbanbiketech.com/Abus-Gr.../810001-01.htm

The massive, parabolic 16mm square section shackle is produced from proprietary hardened steel, making it massively resistant to cropping and twisting. The square cross-section presents 20% more steel versus a round cross-section. It is also worth mentioning that Abus owns and controls the entire supply chain for their proprietary hardened steel. It stands up to cutting and grinding attacks better than the standard, mass-produced hardened steel used by competitors which requires significantly larger diameter links and a higher overall weight. The City Chain is rated by Sold Secure and ART at their maximum ratings. That's a good thing.

Let's do some maths:


Everything else being equal
Sround: s= pi x r x r
Ssquare: s = 4 x r x r
4 > pi

r krypto mini = 18/2 = 9mm
r abus extreme 59 = 16/2 = 8mm?

Skrypto mini = 254.47mm2
Sabus extreme 59 = Sconvex parabolic square with round corners

We know that Sconvex parabolic square > Ssquare

If r mini-circle at round corners = 1mm (arbitrary)
there is 4 round corners

Ssquare with round corners = Ssquare - S1mmwidesquares + Scircleatroundcorners
= 16 x 16 - 4 x 1 x 1 + 4 x (pi x 1 x 1)/4 = 256 - 4 + pi > 255mm2

then Ssquare with round corners > 255mm2 > Skrypto mini = 254.47mm2


Sabus extreme 59 > S krypto mini

+

better quality process claimed for abus

+

for most theft attacks: parabolic square section shackle > round section shackle

What remains unknown is which lock has the best hardened alloy against an angle grinder???
Any test???

Nevermind, the abus extreme 59 has a big weakness


Ever heard of the hardlock lock?
They claim it is theft proof even against an angle grinder.
I can see some weaknesses