Home Made U-Lock Bicycle Lock by TimAnderson
Make your own bicycle lock.
It can be lighter, cheaper, and much more fun than any lock you can buy.

Here's one made of cardboard!
It's perfect for use in Japan and other nice places where people don't like to steal.

I live in the United States where lots of people steal things.
So we'll make a stainless steel one from an old stove.
 
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Step 1: The Ancient U-Lock

The "Modern" U-style lock is pretty old. Here's a patent for one from 1925.
It's designed to fit over the spoked wheel of an automobile.
Back then lots of cars didn't have locks.
As Henry Ford said "You can have any color you wanted, as long as it's black."
So people accidentally taking the wrong car must have been a problem.
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Hazzard2theworld911 says: Aug 12, 2012. 5:19 PM
What a nice way to scrape the paint off of your nice cannondale...
EarlyGrayce says: Dec 7, 2010. 8:55 PM
"As Henry Ford said "You can have any color you wanted, as long as it's black."" is a misquote, the first few generations of Fords were not even available in black.
sk3lton says: May 26, 2011. 5:56 AM
"As Henry Ford said "You can have any color you wanted, as long as it's black." is not a misquote i can't remember what model of car it was for but he did famously say that
ilpug says: Jan 19, 2012. 7:00 PM
If they weren't black, what were they?
EarlyGrayce says: Jan 21, 2012. 5:04 AM
Ford wrote in his autobiography that he told his management team in 1909 that in the future “Any customer can have a car painted any color that he wants so long as it is black”.
From 1908 to 1914, the Model T was not available in black but rather only grey, green, blue, and red. Green was available for the touring cars, town cars, coupes, and Landaulets. Grey was only available for the town cars, and red only for the touring cars. By 1912, all cars were being painted midnight blue with black fenders. It was only in 1914 that the "any color as long as it is black" policy was finally implemented.
The model changes were not designated by a new letter but frequently under the banner of Model-T which was also seen more recently with the VW Beetle that change dramatically over the couples of decade they were built although they kept the same name and styling. 
ilpug says: Jan 21, 2012. 12:09 PM
Huh. Interesting!
sk3lton says: Jan 21, 2012. 3:45 AM
That was the whole point you could only buy the car in black and I have since researched what model car this was and it was the Model T in 1909
Zeppelinfreak says: May 15, 2011. 10:36 AM
Chain and a padlock
stupidloginthing says: Sep 10, 2009. 10:38 AM
any thief with a bolt cutter could have that bike in 2 seconds flat.
2 stroke says: Sep 20, 2010. 8:46 PM
nah tin snips will also do it
weldor says: Dec 30, 2010. 11:29 AM
Depending upon the thickness and type of stainless steel used it can be quite a chore to cut through with snips. Stove tops are typically a 300 series ss which is not as hard ad the 400 ss. It is typically tougher (this is what makes ss such a pain in the rear to work with). The wider the strap the more trouble it will be to get through.
The lock in the pic is a Masster Lock. Although typically a decent lock, I knopw how to destroy one in a matter of seconds. Master does make a lock that has a hex shaped shank. There are other types of locks that are harder to break as well. They typically have what is best described as a "warded" shackle. Look them up on the Maaster Lock web site. There are other companies that make good locks as well. Some of the knock offs are pretty stout as well. I would recomend using a lock that is stainless as well- no rusting and all but impossible to cut with a torch as well as a real pain in the keister to cut with a saw.
2 stroke says: Dec 30, 2010. 8:51 PM
cordless angle grinder
bo88y says: Sep 4, 2010. 5:08 AM
Any thief with HANDS....
sora says: Sep 24, 2010. 4:14 PM
unless its a stupid theif
guitarmonk15 says: Jul 19, 2010. 4:27 PM
Any thief with a bolt cutter could have most bikes in a few seconds. Most bike locks are meant to prevent the casual/semi casual thief (just walking around, and steals a bike without intending to do so that day, or similar variants). If there's a gang of thieves driving in a van with power tools or even a bolt cutter, Your bike is pretty much gone, unless you have a bunch (10+) of insane strength locks.
AnarchistKid says: Feb 12, 2008. 12:14 PM
if i wanted the bike bad enough, id bend it back and forth till it breaks.
weldor says: Dec 30, 2010. 11:15 AM
Stainless steel will not break by bending it back and fot\rth as you suggest. However, it will proceed to getr hotter and hotter until you burn your fingers. JUst ask anybody who works with metal for a living.
EarlyGrayce says: Dec 7, 2010. 9:00 PM
Funny to see your gloved hand on the handle and the bare one near the blade.
SuperCoPilot says: Oct 16, 2010. 2:33 PM
i found most of the time when you buy a lock from a bike lock exclusive company, they're usually more than happy to reimburse you for the bike
onrust says: Oct 3, 2010. 4:02 PM
Here in the states (Tucson) I lost 3 bikes in less than a month. You have got to look at what anything is locked to. Screw the cardboard lock, a hack saw will cut the chosen post. Its not brain surgery and this is why people get robbed.
dan_o_89_rs says: Aug 18, 2009. 7:01 AM
looks nice. inexpensive, yet perfectly functional... looks like the edges might need a covering of sorts to protect the bike's paint. but nice..
mattyew says: Apr 12, 2009. 9:13 PM
i have a caad5 myself, but i prefer using name brand locks like kryptonite cause they have a reputation for being very difficult to break. nice bike!
Yerboogieman says: Oct 9, 2008. 8:47 PM
this one kid used to lock up other peoples bikes with U-Locks
engineerable says: Nov 23, 2008. 10:05 PM
Switzerland is pretty much the same. My father and I were bike touring through switzerland, and most of the bikes were never locked up. Several times I saw very expensive bikes just sitting against a wall, or stuck in a bike rack with no lock. At most they use the locks that just keep the rear wheel from rotating. Too bad it isn't like that everywhere.
carlo$ says: May 30, 2008. 11:26 AM
great idea.
quicumque says: Nov 29, 2006. 6:37 PM
If I was some average dude (which I am not), that thing would send me off just by the looks. I say instead of adding extra weight to deter cutting devices, just make the edges nice and sharp, add some red dye at random intervals. Great job, and very nice article!
unspecified says: Feb 12, 2008. 1:01 AM
I love that plan!
unspecified says: Feb 12, 2008. 12:55 AM
Man - I just don't know about this one at all. I mean - if you have to weld as a step it implies access to a welder and most likely some steel bar stock. I am jumping on the "way too flimsy" boat - especially since all of that work went into it. I also don't imagine that a lot of people want a sharp edge gouging their paint every time they have to lock the bike. I dunno Tim - it seems that you are into "living small", but saving on the materials will certainly not offset the price of another bike. Also, the lock in the first of the final 2 pics seems to be open to shimming, preventing which I would have thought was one of the boxes key functions.
Von Klaus says: Jan 3, 2008. 11:55 AM
yeah any criminal can quickly snip that lock in two. rememeber kids. always lock your bike in a well lighted area. but, it is a good idea if you live in an area that people don't steal crap.
frogmeetcog says: Jan 3, 2008. 11:01 AM
GOOD quality stainless steel is, as Soapy here already said, not possible to drill into, much less pound through with a hammer and screwdriver. Whatever Chinese metal that is, it's pretty soft, and thus not remotely theft resistant. I have some German stainless plates from the scrapyard, and I can barely get through them with a anglegrinder and several good grinding wheels! Nice Cannondale, though. I would ship the author some of my stainless plates just for the heck of it, but they weigh a ton!
julianwisbey says: Nov 25, 2007. 4:47 PM
you should cover the peices in some old inner tube cause thats gunna scratch the shit outa your poor dale
razordu30 says: Nov 14, 2007. 6:52 AM
Wow....if I were you, I'd consider throwing a garbage bag or something over your bike as well, to cover the labels.

A Cannondale locked with the scrap pieces of a stove top = rich and happy thief
PKM says: Oct 12, 2007. 5:05 PM
Hmm.. I can't say I really see the point of this design. If you're going to carry a U lock at all you might as well make it a secure one. I know no lock prevents theft, they are only deterrents, but if your lock deters anyone except some kleptomaniac wielding a gas-axe and a chainsaw I'm happy enough, and a nice certified lock also means you can get theft insurance. What I would love to see is a small or foldable design for a reasonably strong lock I could use to secure my quick-release wheels. Locking the frame to something immovable is all well and good but unless I carry three locks at a time some scally is probably going to make off with my brake discs.
stasterisk says: Aug 15, 2007. 6:11 PM
For instance, here's how to TIG weld!
Karim says: Dec 4, 2006. 6:10 PM
but some one or almost anyone can break off card board!!!
kittyno says: Aug 13, 2007. 12:03 AM
yes, that's why he made a metal lock.
CaffeineHouse says: Jul 27, 2007. 7:30 PM
hahahahahahaa you really think so? only like, the strongest guy in the world can break cardboard!
heavy.metal.nguyen says: Nov 22, 2007. 7:23 PM
It is SO hard for me to break cardboard. I mean, I can rip rip telephone poles in half but CARDBOARD?! Holy crap I could not do it! lol
chris_too_cool_for_school says: Jul 10, 2007. 10:45 PM
Nice little alternative to not having a lock. If I had a cheap bike I'd make one. If it were mine I'd make it smaller, and lock through the back wheel and rear triangle - it'd be far easier to cut through the lock than cut the wheel.
Fat_Head_Carl says: Mar 6, 2007. 4:19 PM
I like the ingenuity - perhaps a smaller "u" will be less vunerable (something that fits very closely to a standard-sized pole in your local town). Ive seen the "tire-irom / pipe twist the lock off" trick first hand... As a serious PSA I must advise you can NEVER lock up a bike of worth (Cannondale, Trek, etcetera), it's never safe, no matter what lock you own.
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