Zen Backpack Zipper Security






Backpack Zipper Security


Backpack Zippers

Zipper Maintenance/Repair

Zipper Security

Zipper Locks


Backpack Security


Zipper Security

From a security standpoint, second to leaving our backpack unattended and unsecured, the zipper is generally the weakest point.  An unlocked zipper allows entry into your pack and access to it's contents, even when on your back.


Some mini cable locks can be threaded through the back of most backpack zippers where the zipper pulls are attached

This allows you to lock most reasonably sized zippers without modification


To make zipper entry less desirable to the opportunist thief, you have several options, such as padlocking, ziptieing (use of a cable tie) or even securing your zippers with a snap-link or clasp.  It is important to note that these precautions are only meant to slow or deter a thief and do not guaranty theft protection.  


Padlock Sliders with Multiple Locking Tabs


Snap links and clasps can be undone, zipties can be cut and locks can be picked, decoded, and even cut.  And even if you you have what seems like a very secure zipper setup, a motivated thief can often open a zipper with a simple ball point pen.



Locking zipper pulls close to zipper slider allows less play than placing lock at ends of zipper pull


A metal ring or loop at the end of the zipper allows you to secure single and double pull zipper sliders



A locked zipper can often be opened without tools by pulling opposing edges apart where locked zipper sliders meet each other or the end of the zipper.  The closer the slider ends are from opposing sliders or the end of the zipper, the more difficult it is to gain access to the pack.  That said, locking the outer ends of a zipper pull is less secure than locking the inner holes of zipper pulls, which is less secure than locking zipper sliders designed for padlocks.



Pacsafe bag with snapping hooks for securing zipper pulls

S-Biner holding zipper pulls together


Zippers with only a single slider can be locked by adding a D-ring or fabric loop (with or without a metal core) at the closed end of the zipper and locking the slider to this.  You can also use a snap-link or clasp of some design to allow for securing your slider to the end of the zipper without needing to fumble with a combo or key.  A simple snap-link closure is easily defeated, but can deter against pickpockets - especially when using a link with a threaded lock and/or when the link is hidden out of site (under a flap).


GooglePatents  US20030145636

GooglePatents  US7712160

GooglePatents  US1819349

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GooglePatents  US1819449

GooglePatents  US7073233 zipper buckle

GooglePatents  US20090106951


zipper patents

GooglePatents  US1889337

GooglePatents  US2394732

GooglePatents  US3955248


Padlock Zipper Slider

Hasp Padlock Zipper Slider

Padlock Zipper Slider

with single locking tab

Hasp Padlock Zipper Slider


If you are using a backpack without lockable zipper sliders, you can retrofit your pack with updated sliders.  Lockable zipper sliders can be purchased from luggage repair specialty shops (such as Ohio Travel Bag or hardwareelf), homemade or salvaged from luggage (try Goodwill or thrift shops).  Replacing zipper sliders isn't that difficult, but it does require a little finesse and a little fiddling to get everything lined up just right.


GooglePatents  US2517403

GooglePatents  US4081882

GooglePatents  US3944032

GooglePatents  US20120180271

GooglePatents  US20130340213

GooglePatents  US1919966

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GooglePatents  US1941177

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GooglePatents  US4123829


Padlock Sliders with Single Locking Tab

Padlock Sliders with Single Locking Tab

Zipper separation with long shackled lock

A sleeve could be added to the shackle to allow for a tight fit

A Cable lock can allow for a lot of play between zipper slider

It would be easy to pull zipper apart and fit hand in this bag.


Note that when choosing a padlock sliders design that sliders with single tabs tend to be more durable than those with multiple tabs, but can allow for enough separation of the zipper to be a problem.  It only takes a small opening between the sliders to allow sticky fingers access to your pack and allow them to make an opening where the sliders meet.  Lengthy shackles as well as those with skinning shackles allow for greater zipper separation.


If you are crafty, you can make your own lockable zipper sliders.  DIY zipper sliders include:


If you decide on making your own lockable zipper, you will find that making a securable zipper pull is much easier than making a securable zipper slider.  See below for ideas on how to make a lockable zipper slider.


Padlock Hasp Zipper Sliders

Padlock Hasp Zipper Sliders


Padlock sliders with a hasp design tend to be pretty sturdy in design, but tend to jingle quite a bit when not locked.  It is difficult to pad these zipper pulls and still allow for the hasp to function properly and may be better suited for packs that are to be locked when in transport.  They may not be ideal for daypacks, unless they are always locked when worn or if the little jingle doesn't bother you.


Keyed Hasp Lockable Zipper Slider

Keyed Lockable Zipper Slider

Keyed Hasp Lockable Zipper Slider

Keyed Lockable Zipper Slider


Sliders with a built in locks can usually be easily picked with a paperclip and the keys may of course be easily lost.  Ones with the lock built directly into the slider generally force a tooth into the zipper and prevents the zipper from being fed through the slider.


If you are not able to use or install a locking zipper slider, you can make a lockable zipper pull out of stainless cable (either coated in vinyl or small cord) and crimp it to your slider.  If you make a long zipper pull, you can add an extra crimp in the middle of the pull to allow for a usable length pull and a tight lock.  With a bit of work, metal cable can also be sew together to avoid need for a crimp.


Zipper pull made from Steel Cable


Lockable Zipper Pull options:



Sewlock zipper end prevents separation of zipper once locked


Even with padlock designed sliders, nimble fingers can easily separate the zipper unless the sides of the zipper are firm and prevent flexing of the unzipped zipper between double sliders.  Semi hard luggage with plastic reinforced sides are difficult to tamper in this manner, but access into soft backpacks can often be done by just pulling on the fabric adjacent to the zipper sliders.  Firm plastic or metal may be sewn or riveted to the sides of zippers to help prevent zipper separation when sliders are locked.  Locking the sliders to a D ring sewn to the end of the zipper makes it a little more difficult to separate the zippers than if the sliders were fix or floating in the middle of the zipper.  Again, the tighter the sliders are locked together, the more difficult it is to separate the zipper.



Zippers, especially the coil type, can be separated with a little bending or/and picking in a manner of seconds and rezipped with locked but free-floating sliders.  Locking your sliders to a fixed position (such as to a D ring at the end of the zipper) will not prevent someone from prying open a zipper, but will make if very difficult for them to cover their tracks and hopefully deter them from doing so.  Plastic and metal tooth zippers are more difficult to pry open than coil zippers, but a sharp blade can usually still open up most any bag without much resistance.


Eagle Creek Rincon zipper lock


Adding and anchor point for your zipper lock makes it very difficult to reclose a zipper which has been opened with a pen.  It can also protects a zipper to some degree as a hard yank to a lock will be partially absorbed by the anchor point and not just the zipper and zipper slider.  This is helpful against yank attacks and damage to zippers when locks get caught on other luggage or the many hazards encounters at the airport.


More information on security can be found on our Backpack Security page.




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