Bike Theft Primer

I’ve written this primer on locking bicycles because I may have some experience and/or information that some of you might not.  I was a university police officer from 1980-2010 and ran a Police Bicycle Unit for almost 20 years and a Crime Prevention Unit and Records Unit for many of those years, as well.  I was also trained to remove demonstrators that had locked themselves to things, so I’ve been formally trained on defeating many, many types of locking devices.  Lastly, my university is inside the Washington D.C. “beltway” and we’re not too far from Baltimore.  As a result, our bike theft problem may be more severe than for many of you and I was in the ideal position to pay attention to what was going on for a long time.  That said, I believe that as gas prices rise and biking becomes more prevalent, the problem will become greater for all of us. 



Here’s the short and sweet of it; bike thieves are opportunists with tools.  If they can find an unlocked, unattended bicycle, they’re happy to take it, but if that chance doesn’t present itself, they use their tools to create their own opportunity.  They want to work fast and unobserved, and they want to ride away on your bike and blend in quickly with other cyclists.  If they’re the kind of bike thief who comes equipped with transport for multiple bikes, they probably have multiple tool systems and you’re in real trouble because there is no bicycle lock that can’t be beaten!  If you lock your $5000 bicycle out in public, there’s no lock that can prevent it from being stolen and no way to keep the components from being stripped off the bike.  Believe me, there’s also no bicycle too cheap, too ugly, or too old to get stolen.  Thieves may find other bicycles that are more attractive targets, but at some point all of our bicycles are targets.



If you’ve read this far, you want to know the “ideal” place and method to lock your bicycle, but you’re not going to like the “ideal” answer.  If you have to leave your bicycle parked somewhere, the most “ideal” bicycle parking is inside your home or your workplace, in a locked area (closet, garage, etc.), locked with at least two different types of locks, and to something that’s anchored to the building frame.  Even then, the locks must be case-hardened U-locks or case-hardened chains/padlocks and the door to that closet or storage area must be closed and locked and under monitored CCTV surveillance or with a nearby guard.  Okay, that’s not remotely possible unless you’re the CEO of your own company.  The next step down, buying a folding bicycle and keeping it locked under your work-desk may not be an option either.  That’s reality and once you accept that there is no perfect solution to bicycle theft, you’re ready for the real world. 


If you want to keep your bicycle, you have some decisions to make, like:

  • How much am I willing to spend?  Better, more secure locks cost more money.
  • How much trouble am I willing to endure or how much time and I willing to spend to make my bicycle less likely to be stolen?


Simply put, your job isn’t to make your bicycle theft-proof; your job is to make it more trouble to steal than all of the other bicycles around it; enough trouble to make a thief steal someone else’s bicycle.  To a bicycle thief, “trouble” is caused by two main things:

  • Multiple, stronger, and generally more expensive locks (you get what you pay for), and
  • Taking the time and effort to put your bicycle in the most secure place possible and then taking the time to lock it up “properly.”


In the real world, no lock “stops” bicycle thieves, but good locks and locking practices can displace them to other bicycles.  If you make any crime more difficult to commit in any specific area, criminals move to places where they can continue their chosen profession.  When it comes to bicycle theft, you just want that place to be away from you and your bicycle. 



Okay, you got this far; here are the best practices, but keep in mind that they’re general rules and aren’t intended to encompass every type of locking device.


  • 3/8” to 5/8” cable locks (coated or uncoated) are virtually worthless as a primary or lone locking device and only provide a false sense of security.  Cables can be a good device for preventing opportunistic, walk-off thefts, but if your bike is out of your sight, cables provide less than two seconds of protection.  Don’t believe hype from manufacturers or dealers about how “their” cable is stronger or better than all the “others.”  Don’t listen if they tell you it’s Kevlar reinforced; a Kevlar thread can support an incredible weight, but it cuts like any other thread or fabric.  Cable locks can be easily beaten in as many as six ways; three by easily concealable, hand-tools. 


Don’t get me wrong, cable locks aren’t totally worthless; they’re just worthless as a single, primary locking device.  Cable locks can be a nice secondary lock and can aid in making your bicycle more trouble to steal.


  • U-locksare a LOT better than a cable lock, but still not perfect.  You generally need power tools or a lot more time to defeat a u-lock.  That makes them less likely to be attacked, but they’re not a perfect solution to bicycle theft and we’re still our worst enemy for two reasons:
    • We buy the cheapest u-lock we can find (you get what you pay for) and
    • We don’t usually use the lock properly or to its best advantage


U-lock manufacturers will tell you that the best you can do is to lock your u-lock through both bicycle wheels, your frame, and a substantial bike rack.  All that material fills the space inside the u-lock and makes it more difficult to defeat your u-lock with “spreader” attacks.  There’s no room to apply tools without damaging what they’re trying to steal.  Of course, almost no one locks their bicycle this way because they don’t want to take the time or don’t know how to remove and replace their front wheel.  A standard, quick-release, front wheel is easy to remove and with practice, only takes seconds, but if you don’t know how, learn; ask at any bike shop.  Let me make this completely clear; in 30 years of police work, I’m unaware of ANY bicycle ever stolen on my campus that was locked with a u-lock, through both wheels and the frame, to an intact bike rack. 



Here’s why this works so well.  If you attach your u-lock through your frame, but not any wheel, your bike can still be ridden away if what you’re secured to can be defeated.  People ride around with u-locks hanging from their frames and handlebars all the time and police don’t pay any attention to this.  If your u-lock is through your bike frame and at least one wheel, your bike is less likely to be stolen than other bicycles with both wheels free because those other bicycles can be ridden away while yours must be carried.  Police officers will notice a locked bicycle being carried.  In fact, I’ve found that a good police bicycle officer will look suspiciously at any bicycle being pushed instead of being ridden; they’re wondering why it isn’t being ridden. 


Okay, let’s be honest; most people aren’t going to take off their front wheel.  They don’t want to get their hands dirty, they don’t understand the theft risk, or in their head they’ve balanced the effort needed to lock their bicycle properly against the risk of it being stolen and they’ve decided it’s worth the risk.  We’ll call these people “potential victims.”  They’re the people whose bicycles will be stolen instead of yours, if you just lock yours a little better than theirs.  Okay, if you’re one of these people, there’s another way to make your bicycle a more difficult target.  If you choose to include only one wheel in the u-lock, putting a cable lock through the other wheel and your frame also makes your bike more trouble to steal.  It’s an accepted truism that different types of locks are defeated by different tools and that thieves usually specialize in only one type of tool.  I wouldn’t bet my bicycle on it, but more is usually better.


Yes, some old models of u-lock could be defeated with a Bic pen and I’ve seen the video on the web, but I’m unaware of any new u-lock model that has this particular flaw.  You can probably also freeze them in liquid nitrogen and then shatter them with a hammer or cut them off with an oxy-acetylene torch, but the ability to transport and use liquid nitrogen and/or welding torches is WAY beyond most bike thieves.  If your thieves are this sophisticated, you’re better off banning bicycle parking except inside secured and monitored facilities. 



There are also what I’ll call “massive chains and padlocks.”  This category includes most over-sized locking devices.  Some look like gigantic handcuffs, but many are just 3-6 foot long chains, encased in a flexible sleeve, and secured by heavy-duty, case-hardened, padlocks or mini-u-locks.  Due to their size and weight, they’re often marketed for motorcycles or motor scooters, but they seem to work just as well as u-locks if you follow the same locking advice.  There are tools that can defeat them, but if used properly, they’re pretty good at displacing thieves to other bicycles.  The advantage of the chains is that they can often snake through both wheels and the frame, without detaching any wheels.  Their disadvantage is their size and weight.  Many bicyclists, commuters in particular, leave these types of locks at their destination and may never actually carry the lock around.



  • Lastly, there are some things to think about that aren’t as obvious as the size, expense, and number of locks you use.  These things can also help reduce your risk of bicycle theft:
    • Lock your bicycle in a highly visible, highly trafficked area; ideally one used by large numbers of bicyclists.  Other bicyclists are probably more likely to call the police if they see a thief at work in a bicycle rack.
    • If your bicycle is out in times of low light, make sure the rack area is well lit.
    • Find a rack that is in the view of local police, guards, CCTV, or watched by any other means.  This observation should be obvious; hidden cameras don’t discourage theft.
    • Look for secure, interior storage areas, like bike-barns, bike lockers, offices, etc.
    • Find an area with active local bicycle cops.  Bike cops are more likely to notice suspicious activity around bicycles and because they’re cyclists, too; they have an even greater reason to hate bicycle thieves.



Before you rush out to park your bicycle, here are the most common locking mistakes we see:

  • Locking only the front wheel allows the thief to steal an unsecure front wheel from a similar, nearby bike and attach it to your bike.  You’re left with your locked front wheel and no bicycle.  Someone else, probably nearby, has a bike with no front wheel.
  • The front fork is not a frame element.  If you lock your bike through the front fork, the thief will remove the bike from the front wheel and pull the fork up and out of the lock.  The bike and wheel are then re-connected and they ride away, leaving your lock, alone and empty, on the rack.
  • If you lock your bike at an inverted-u rack, but the rack has become loose in the ground, the thief will just pull the rack out of the ground to free your bike.  Trust me, they’ll also slide the rack back into the ground and hope to get more bikes off it in the future.  If you use this style of rack, please check them occasionally.  Strike it sharply with your palm before you use it.  If it vibrates like a giant tuning fork, it’s secure in the ground.  If it doesn’t vibrate, report it to whoever can fix it!  If you see someone shaking one of these racks, they’re probably a thief, trying to break a new rack loose for future use.
  • Don’t leave the “lock” portion of your device against the ground.  If you do, many devices can eventually be beaten into submission with a large hammer.  Lock your device in a manner that forces your lock to stay off the ground.  If beating on the lock destroys your bicycle frame, it’s pretty worthless to any thief who steals it.
  • If you lock your bike to something other than a bike rack and whatever you’re locked to can be defeated easily, don’t expect your bike to be there when you return.
    • Thieves just rip bicycles up and off most landscape items. 
    • If your lock fits over the parking meter head, they can just lift your bike off the meter (or sign post or fence post).
    • Wrought iron is actually quite weak at each weld-point; you may not even notice that it’s already broken and bends easily.  Cheap aluminum, cast-fencing, is even worse for security.
    • Chains or cables that stretch between bollards are a horrible place to attach your bicycle.  They’re not there for bicycle security; they’re there to herd pedestrians.  The chain or cable can usually be cut or just pulled out from one end and every bike along that chain or cable is now loose.
    • Arms and legs of decorative lawn or patio furniture are easy to break and separate.  Thieves then push them back together with a tiny dot of glue so they look secure to the next bicyclist.


Of course, most bike thefts could have been avoided if the owner had just run their u-lock through at least one wheel.  Thieves don’t want to CARRY a bike away, this attracts unwanted attention, they want to RIDE it away and blend in quickly with every other nearby cyclist.  This is why I say that encouraging bicyclists to use a u-lock through their frame and at least one wheel is a compromise that I’ve decided I’m willing to accept.  They may not be willing to take their other wheel off each time they lock their bike, but it only takes a moment more to make sure you include one wheel with the frame as you lock up.  If they have a cable as a secondary locking device, it can be run through the free wheel to make the bicycle an even more difficult theft target.



In the past few years, we’ve given away hundreds of u-locks and sold many more at wholesale cost.  At the same time, the theft rate for bicycles on my campus has dropped.  The remaining thefts still have one thing in common, over 90% (it varies from month to month) of the victims were only using cable locks.  Many of the remaining thefts were unsecured bikes taken from inside buildings, cars, etc.  I’m aware that there are probably other factors that reduced the theft-rate, like more CCTV cameras, better racks, and better lighting and I can’t easily factor those into the equation, but it seems obvious to me……lots of good racks and lots of u-locks means less bicycle theft.



Here are a few thoughts to help minimize the theft of accessories.  If anything can be removed without tools, it can be easily stolen.  You can fix that or choose to live with it:

  • Change your seat post quick-release to a bolt; how often to you really adjust your seat height?
  • You can replace wheel quick releases with bolted axles (yuck) or with locking mechanisms ($$), or you can put a fat zip-tie on the spoon to hold it tight against the frame or fork.  It’s not perfect, but it makes it a little harder to open the spoon.  If you carry tools to do road-repairs on your bike, you should have something that can pop the zip-tie if you get a flat.  If not, with a little more effort, you can fix the flat with the wheel still on.
  • Lights?  Buy lights that bolt or screw on, get ones with quick release clips, or buy cheap enough to not worry about the loss.
  • Computer?  Pop it off and take it with you.  It’s unlikely that a thief really wants your old, used model, but expensive wireless units might be worth a thief’s time.
  • Panniers or other bags?  Take them with you or switch to a courier bag that you wear on your back.
  • Don’t leave your helmet on your bicycle even if it’s threaded through your lock.  They can be unstrapped and stolen or just cut off with a knife or scissors.  Carrying a stolen helmet can make a bicycle thief look less suspicious when hanging around a bicycle rack waiting for an opportunity.  Let’s not provide their camouflage.



Lastly…….here’s the additional advice we should give to everyone………..please, please, please…….register your bike with somebody, record your serial number somewhere, be able to give a detailed description of your bike, and always report it if it’s stolen.


Good luck.


John Brandt

Bicycle Coordinator

University of Maryland, Department of Transportation Services


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One Response to Bike Theft Primer

  1. Excellent information! Thanks for taking the time to write this, John!

    I like to use an old balance scale to illustrate the concept of convenience vs. security. The more secure the item is, the less convenient it is for anyone, including thieves. If you want your stuff to be easily, readily, conveniently available for YOU, just remember that it will be more convenient for a thief, too.

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