No more big key chain for you - create a single key family bike lock system

Viro Blocca Catena large - my favorite bike lock

This will be the most fun you'll ever have locking your bicycles!

If you have a bunch of people in your family riding bikes, as we do, you have probably had a time or two where somebody's bike key has gone missing and you've been stuck, unable to unlock a bike you wanted to use or to lock a bike when you're out (usually with a kid needing the bathroom). This can be even more complicated with lots of bikes in a family who rides together. If that hasn't happened to you yet, you are better organized than we are. We found out how to minimize the problem, though!

This one key will open all of these locks.
I don't need a big key ring to manage the
bikes and neither does my spouse.
Abus 34CS/55 and two 34/55 models.

Having a single key system for all your bike locks takes the hassle out of locking up. It's great for family cycling and it's easy to arrange. If you have a bunch of bikes to lock up, it's easier not to have to search your pockets for the right key for each lock while the kids distract your attention. You can get everything unlocked or locked in much less time. It's especially handy if you lock a bike where your kids are at school or daycare that your partner needs to pick up later. Everyone has the same single key on their chain. You can grow the system from before your first baby to herding 4 kids around as your needs change.

This is good for kids too. Kids love to take responsibility by carrying their own locks and keys, yet parents can still open the locks if needed. There is no need to sacrifice security to do it either. If you want, you can also put together a lock system that is keyed so that all the grownups can open every lock, while the kids can open only their own locks. Then if the kid loses a key your grownup bike is still secure. Options for your family key system follow in a minute. First, you should choose the general type of lock you plan to use.

Kinds of Locks

U-Locks (also called D-Locks) - a solid steel U that hooks into a thicker bar
These are strong, pretty lightweight and small for what they offer but I prefer a chain and padlock. There are lots of different levels of quality. A small sized well-known-branded lock with thick steel parts and a locking connection on both sides of the shackle is safest but expensive. Cheap ones are cheap steel and don't protect well.

By 'a locking connection on both sides of the shackle', I mean U-locks with a little bite out of the metal on both sides of the U (instead of one side with a bite and one with a bent end or hinge or something). They are locked by a steel ball on BOTH sides of the main lock body, and they are MUCH better. It takes one cut to break a U-lock that only locks on one side, but may take TWO cuts to open one that locks twice. Twice the protection!

I am not aware of any rekeyable U-locks. But if you like U-locks, there is one way to get them keyed conveniently. Contact the manufacturer, either directly or via a locksmith or dealer, and order new locks you want all keyed alike. Sometimes they'll key new ones the same as one you already have. We did this once and Kryptonite didn't even charge extra to do it. It takes a few weeks for them to ship your order. Then all the keys fit all the locks. This is kind of expensive since good U-locks are not cheap, and kind of inconvenient since many of the things a U-lock will fit around are easy to remove (street signs and 'sucker poles', for example), but it's simple since you only need one key for everything and all the locks work the same. The same special order method applies for any non-rekeyable padlocks including Abus folding bar locks and chains with integrated padlock ends.

4/13: Someone recently noted in the comments that not all manufacturers can key new locks to your old one anymore. You have to buy all new ones. Too bad - try asking anyway and maybe they'll do it again.

Folding Bar Locks
These fold up like an old fashioned carpenter's ruler with a lock on it. Abus makes a lot of them. Word has it that the best ones are good, but the cheaper ones can be opened fast. They can be special ordered alike I think from the manufacturer.

Padlocks and Chains
With a padlock and chain you have a lot more freedom to change things or lock anywhere. A chain fits around large and unwieldy objects and allows you to lock your bike a small distance away from an object. Generally speaking, you want at least a meter of chain ($25-$100) and a heavy duty padlock ($15-80). This is heavier than a U-lock but more versatile.

A chain that's locked with a good padlock needs TWO cuts to get through it. Look for a padlock that also does, like the ones recommended below, with a sliding shackle or with a locking point on both sides. Try to maximize the number of difficult cuts through steel that a thief would need to make to get your bike.

our favorite locks are usually found on Italian mopeds

It's good to get a padlock that's at least as hard to open as your chain itself. A (10mm +) thick, special alloy shackle is a good idea, as is a shrouded shackle (like the biggest silver Abus 34CS/55 in the picture at the top - same lock as the others but with a shroud) or monoblock design (like the Viro locks pictured here). If a thief can't reach the shackle with a saw or other tool, the lock is safe. Lock picking is uncommon, takes time and anything of good quality is probably fine in this regard. (More pins, mushroom pins, or anti-bump pins = better anti-picking protection.) I recommend getting a rekeyable or KnK lock (see below) so you can rig up your family key system. Here are links to a Dutch cycle club site and a German test magazine that tested locks for strength.

The chain should be as thick as you can stand to carry, 10 mm or so, and in a city it must be very strong hardened steel like the Abus, OnGuard, Pewag and Kryptonite chains in the pictures. They won't cut with a normal chain cutter or hacksaw. Some people say you can get away with 8mm chain but we don't. 6mm isn't enough.
Chain length: The standard 3 foot (ca. 94 cm) chain will just barely fit around most of the big streetlight poles in downtown Chicago with room for your frame, but you would be happier with 4 to 6 feet of chain. This gives you a chance to use one lock on your bike plus a couple of kids' bikes or your partner's bike too. A short chain will fit on a sidewalk bike loop or rack easily though. Some chains have a ring on one end that seems handy; you can also loop it around a streetlight pole and use a U-lock to connect it to your bike.

A thick chain from the hardware store will work in low security settings - the red one in the picture down below is one of our kid's locks with normal chain in a tube of climbing tape (about $1 a foot at any rock climbing supplier) - but don't follow our example. It can be cut in no time with hand tools. The advantage is that it's cheap enough to use on a toddler bike.

Ready Made Chains
One easily found model we like pretty well is the Abus 10 KS chain, 110cm, with a 34/55 padlock, (34/55/10KS110) last seen by us for about $80 altogether (marked down from $125) at  a local bike store in Chicago in 4/13. It can also be supplied with a shrouded padlock, the 34CS/55 in the top picture, and both can be rekeyed by most locksmiths. The 110 cm chain is long enough to lock to a streetlight pole and a little longer than the similar Kryptonite chains. 
We have had good luck with the 10mm Kryptonite chain that came with a small Kryptonite Evo padlock but the lock itself froze up eventually and had to be cut off by the locksmith, so now we use the chain with a Viro lock. If you get one keep it oiled. They make bigger chains too though they get to be too bulky for us.
OnGuard also makes good 10-12mm chains. The plasticky parts fall off the padlocks but they are supposed to be secure. 
If you can't find these options in a bike or lock store look in a motorcycle or scooter shop.

Chains with integrated padlocks
These can be quite good - they are usually made of a 6 to 10 mm chain about a meter long with a big blocky plastic shrouded lock permanently attached to one end of the chain and a shackle-like rod on the other end. With a 10mm chain they should be fine, and some have won certification from ART or SoldSecure, but they can't be rekeyed as far as I know so you'd have to order them all keyed alike like the U-locks above.  I'm not sure exactly what the advantage is of having everything attached, and they are, if anything, bulkier than the chain-and-padlock version of the same idea.

Other Locks we don't like
We don't recommend any of these as a first line of protection. Spend the extra money on getting a better or longer chain and a better padlock or U-lock (or both!) instead.

Cables of any kind can be cut with very simple cheap tools. Don't waste your money. Thick, thin, armored: doesn't matter, easy to open. (remember this if nothing else!)

Café locks or wheel locks, those rings that click around the wheel while you just run in to the cafe, are pre-installed on many European style bikes. Axa and Abus make a lot of them and many older models can be opened very simply due to design errors. I think they are only useful to keep the wheel attached while the metal recycling guy picks up your whole bike and throws it in his truck to go sell to the Prolerizer. Maybe manufacturers can special order them keyed alike. Some may be useful to lock the wheel to your (well-secured by another lock) frame - look for the Sold Secure or ART certification for good ones - but I'd still rather have a better chain or U-lock for the extra money.

Special locking skewers, seat chains, etc, have serious drawbacks and even the good ones can be opened simply. Get plain hex bolt fasteners for hubs and seatposts to replace the quick releases but that's enough. If your seat or wheel is so nifty that someone will steal it, remove it every time and lock it with the chain, or change it and the seatpost out for a cheap set, or be willing to replace it. A cable or a bike chain through the seat can be cut easily, so they work only to prevent drunken vandalism, not real thieves.

How To Set Up Your Family Key System

Most padlocks, U-Locks, or similar non-rekeyable locks
You can get several copies of any nonrekeyable padlock keyed alike from the manufacturer for a basic but not very versatile single key system. This is hard to alter as your family changes but everyone has the same one key and it may be all you need. 

Rekeyable Padlocks
These have huge advantages over non-rekeyable systems, especially as your needs change, or if you lose a key that someone might use to take your bike. They can be set up and changed locally at any locksmith. And you can use them to make a custom key system. For example, a lock shop can key them all alike (easy and cheap) or set all the locks to open for, say, the grownups' keys while each kid's key only opens his or her own lock. That would be a variation of a master key system like those used in buildings or institutions and costs in our experience between $15 and $20 per lock if you have someone do it for you.  For one cheap alternative to this fancy master keying, costing maybe $5 per lock, you could use a full 6 pin cylinder in your grownup locks and only fill 5 pins in the kid's lock, giving the kid a shorter key that has only the first 5 pin spaces. The extra parts of the grownup key just spin in the empty space in the kid's lock, but the grownup key opens everything; the kid's key only opens the kid lock. The kid lock then has somewhat less security against picking than the grownup lock but most house keys have only 5 pins so it's not that bad.

Ask them to use the special high security pins when they rekey your lock if possible to limit picking. The cost difference is slight if any. 

With standard rekeyable padlocks you are pretty much limited to the single keyway (keyhole shape) that that padlock company uses - American, or Master, or Abus, or whatever. They can be versatile, secure and comparatively inexpensive but can't match your door key and might not let you change things as much in the future.

An even more flexible route is to use KnK (Key in Knob) padlocks.  You can match your bike locks to the door to your garage or basement with these, so one key opens the door, unlocks the bike, and fits easily in your pocket when you go out.

KnK lock cylinders - the thing your key fits into in a door handle - are usually used in buildings, but some special padlocks can use them. I listed some below. Prices vary, but start at about $10 for a common house key shape like a Schlage C or Yale, on up to maybe $65 for a really odd high security cylinder with restricted duplication.  You can have a bunch of different models that all use the same key, too. This is probably something to talk about with a locksmith. If you have the cylinders you can get a rekeying set cheaply at Menard's or other hardware stores for a few key types including Schlage C and Kwikset and rekey it yourself. No special antipick pins in this set. KnK padlocks are usually going to be from a good lock shop; some models are listed below.

A lock with a key in knob (KnK)
cylinder like a regular house door lock

this is a small KnK padlock for medium low security

Suppliers and Brands:

• Your Local Locksmith
  A good choice for the fiddly work of rekeying everything alike, but not usually a good place to find a chain. Maybe they can order you one. Local locksmiths will be able to make all kinds of things work together if you tell them what you want.
• Bikeregistry.com
  This internet site from Texas sells - or used to sell - great PEWAG brand chain and good Abus locks at an incredibly affordable price. They had bulk chain for $7 a foot, a complete chain and lock was about $38. Try the link, maybe they have it again.
  
• http://lockitt.com/Lockitt/category/SPCH.html sells bulk chain and locks, haven't tried them myself but look OK.
• Irv's Bikes in Pilsen always has a bigger than usual variety of Abus, Kryptonite and Onguard chains and U-locks. Many are rekeyable, especially the Abus, and they often have low prices.
  
• Your Local Bike Shop
  They will sell the usual U-lock and Kryptonite or OnGuard chain options. Go see what they have. Stay away from the cables. If you like folding ABUS bars this is the place to get them, though they are not rekeyable and the cheaper ones open easily. Nothing in a bike shop will be keyed alike, but maybe you can order it through them that way. Compare prices well.

Padlocks that seem pretty good (not a complete list)

Look for the UK's Sold Secure gold or silver or Holland's ART **** ratings on bike-related lock packages or look at their websites for independent evaluation lists of many locks. Some of the following locks aren't tested since they aren't sold specifically for bikes but your locksmith will probably know. Bike locks come with extra insurance sometimes but you pay for it in the high initial cost.

If I had to choose one new lock for all my family's bikes, I'd choose the Viro Blocca Catena, all keyed alike, since it's not as heavy as the other options, if I could find it. It's simple and not rekeyable but its design compensates for that for me. For a more complicated key system I'd go for the Abus 83CS/55 (or the American A748) and maybe use my house key in the plan.

• Shrouded locks like the American A6360 or A748 seem to be good nontraditional bike padlocks and they are easily available in locksmiths shops. Others include ABUS 34CS/55 (often sold with chain as here) which is in the top picture, and Master 7045KA. None of these are KnK but all are rekeyable.
  

• 

  good locks but this is low security
  chain for a toddler bike

  KnK: Abus 83CS/55 has a steel body, is shrouded, and takes KnK cylinders. The 83/55, 83/60 and 83/80 are big steel KnK locks without a shroud. Abus makes some monoblock designs that are a good alternative. Here's a link to the ABUS page. There is a Schlage/Kryptonite KnK lock, the KS72 pictured above, that looks like the ones on truck trailers - it's kind of heavy but works OK and it's cheaper than the others. There are some small Abus 83/45s on junk chain and the KS72, all keyed alike, in the picture here.
• VIRO was an Italian company, now part of Assa/Abloy, that makes the locks the City of Chicago uses to boot cars. One excellent but not rekeyable model for bikes is the Monolith, a cheaper alternative is the Panzer.  The large Blocca Catena is on nearly every moped in Italy and it's not easy to break. I don't know who the Chicago locksmith dealer is; I got mine pictured earlier very inexpensively from a hardware store in closeout. Order them special to get them keyed alike since they aren't rekeyable.
  
• Fancier Expensive Padlocks
  I don't think it is worth the money to get a restricted unpickable keyway on a bike lock but if your needs are different (to make it match your house, for example) you could try Mul-T-Lock or Medeco. There are a few locksmiths in Chicago with these including the Security Shop, with whom I've always had good luck.

Lock Terminology 101

• SHACKLE - the bent U-shaped thing on a padlock or U-lock that holds what you're locking
• CYLINDER - the round thing that you put your key into and that can spin if the key fits
• PINS - the metal rods inside the lock that keep the cylinder from spinning unless the key fits. There are usually 5 or 6 of them in most locks.
• KEYWAY - how the zigzag slot in the cylinder is shaped. You can't stick a key with the wrong keyway into a lock at all.
• SHROUDED padlocks have a steel thing all around the sides of the shackle so it's hard to get cutting tools close to anything important.
• MONOBLOCK or SLIDING BOLT padlocks have a straight bar for a shackle that pulls in and out of the lock body, which itself is shaped like a squarish U. The ends of the chain fit in the U and then the bar goes through the links and clicks closed, which keeps the business end of the lock hard to reach with cutting tools. This is what they usually use on car wheel boots.

Bike Locking, in General (stuff you already know)

No bike lock is perfectly safe, no matter what. But if your bike is locked better than the one next to yours, maybe it's safe enough. Good U-locks, high security chain and padlock combinations, and folding bar locks are usually enough. Cables, combination locks, weak chains, padlocks or U-locks aren't worth the price. When in doubt, ask a lock shop. Here's a Slate Magazine review that's not too old. 

Get insurance if you really can't afford having your bike stolen. 

The most important thing to think about when locking your bike might not be how super impenetrable your awesome locks are, but rather how well you are connecting everything together. Be SURE that your lock goes around a major part of the bike frame and can't be removed, like one or two of the main tubes, and through the (preferably back) wheel too. (A back wheel costs a lot more to replace than a front one.)

Be extra careful about locking through the front wheel - people always do this and miss the frame. Often a thief could disassemble the headset or wheel and take the rest of the bike easily. The stem is also a bad place since the handlebars can be taken off. 

Also, ALWAYS keep the bike LOCKED TO something that's hard to cut, not just to itself, even if it's inside your garage or stairwell. You can get an "anchor" at the locksmith to facilitate this if you need it. Note that many poles on sidewalks can be unbolted and removed, so find a better place. And try to avoid leaving your bike out somewhere for very long (especially regularly in the same place). It doesn't take long to steal a bike. Sheldon Brown has his own strategy for locking here.

Oh, and a cable lock is as secure as a piece of string, even for a kid's bike, so never ever use one for anything important. Look at the statistics on Chicago stolen bike registry to see why (and for more tips).

updated 4/14