PurpleFrog
Kona Fan
A really heavy duty chain is going to be absolutely the strongest
thing you can hang your bike on. Bolt and chain cutters were designed
to go through round sections of steel. Making the steel from strong
alloys, hardening them and making the links square all contribute to
making a chain too tough to cut.
...Here's the recipe for my home-made case hardened chain with shielded pad-lock:
Find a good hardware store or metal yard and ask for some Cambell
Security Chain. This stuff is 3/8" thick made from Boron-alloyed steel
and is Case-Hardened. It is almost impossible to cut--it destroys the
jaws of bolt-cutters. You can get through it with a torch or diamond
grinder but it takes a while. Ask the hardware store clerks if they
can cut it a little shorter for you--if they say YES, then this is not
the right chain. You want them to say "NO, we just sell it in pre-cut
lengths." It sells for $5.00 to $7.50 a foot, depending on whether you
buy it from a steel yard or a hardware store.
You will want two to three feet. Two feet is a snug fit through the
frame and wheels around a parking meter. This is the same size as a
medium-sized U-Lock. Two and a half feet is perfect. Three feet leaves
you a little room to manoeuvre with so you can lock to big light poles
or lock-up a friend's bike with yours when you're out on a date--this
is a very gallant touch.
Slip your chain into something to protect the finish of your frame. I
stretched one chain into a snug innertube...
Now get a lock. There are a lot to choose from. I suggest a lock with
a case-hardened and shielded hasp. Abus, American and Master make
these and they are all excellent locks. The ABUS DISCUS 40 sells for
around $17.00. The AMERICAN 5300 is the toughest and heaviest and
sells for around $30.00. I chose the MASTER LOCK 37-D because it is
used by the military for high-security applications. It costs less
than $11.99 and it looks mean and ugly.
Total weight for a three foot length of chain and Master lock is 4 7/8
lbs, total cost $33.00
I found something pretty damn similar in the shape of this -
http://www.screwfix.com/prods/38231/Sec ... l-Padlock#
- 10mm hardened boron steel links and a padlock that locks like it will be a real bastard to use bolt cutters on. The sort of thing that we might pay three times as much for from Abus and four times from Kryptonite?