May 1, 2007

Lockable Backpack Zippers
Vancouver, United States

Replacing the zippers on my new backpack with a lockable variety—a tale of frustration and success.

I had my mind made up, I was going to replace my current top-loading backpack with a (front) panel-loading model. These types of backpacks allow for full access to the primary compartment of the pack, unzipping like a book bag a student would carry, thereby eliminating the need to dig through layers of gear to retrieve something.

I am skilled in the art of layering my backpack—it's not balanced for distance walks, but ordered in a variable hierarchy of need and use. I've grown weary of this sensitive layering process though, and believed my reprieve would come in the form of a panel-loader.

My father and I spent the better part of a day visiting every outdoor/hiking/surplus store in the greater Portland metropolitan area, searching for backpacks. The problem here in the U.S. is that our backpacks are actually designed for the traditional concept of backpacking—hiking, camping, etc—and not for traveling. I don't believe this to be the case in Europe, the UK, Australia (and so forth), as the idea of nomadic travel with backpacks instead of suitcases is a much stronger part of the culture—especially for the youth.

My trusted, medium-sized Kelty Moraine 3600 has a capacity of about 59 liters. Every single panel-loading backpack that my dad and I found was no larger than 30–35 liters (closer to that of a day-bag than a primary backpack), save another Kelty, the Redwing 3100 (which offered close to 52 liters of space). The Redwing it would be—but there was a catch: The zippers couldn't be locked.

Insecure backpack zippers

Again, backpacks in this country are trail-packs, and it seemed that most every major brand has redesigned their bags for 2007 without the traditional metal zipper pulls, replacing them completely with nylon cord. I have no doubt these pulls are easier to use, and less prone to breaking the delicate pot-metal that the zippers are made out of, but it leaves travelers without any way to lock the pack compartments.

I saw a few design flaws with the Redwing, but decided it wasn't anything that a few Thai baht and a seamstress couldn't fix. The major concern was the zippers, as the pack would completely useless to me if I couldn't keep thieving hands out of it.

Locking backpack zipper

The search turned to backpack and luggage repair stores that could replace the zippers with the lockable variety you might find on suitcases and duffel bags. I felt like a pinball, bouncing around greater Portland, going from one store to the next. One store claimed they could get what I wanted, but in a week (I didn't have such time); in another a 35-year-old zipper repair veteran lectured me about the futility of locking zippers, and the lack of durability the weak pot-metal provided; while yet another told me to return the pack, as replacing the zippers would be 100% impossible without also replacing the track they ran on.

Apparently the YKK brand (that makes the zippers for my Kelty pack) likes to redesign the mechanism and track every few years to thwart counterfeiters. My zipper, a YKK RCz, was so new on the market repair shops won't even bother stocking replacement parts for them (as none were likely enough to come back for repair for several years). Finding them for sale online would likewise be next to impossible—especially for the type that can be padlocked together.

I couldn't replace the zippers, I wasn't going to replace the zipper tracks, and I couldn't even get a shop to insert a traditional metal zipper pull instead of the nylon cord (as prying up the pot-metal finger to insert it would snap it off). I was, for lack of a better word, screwed.

I had been running around to these various repair outfits alone, and called dad to give him the troubling news. He suggested I run over to Home Depot, a popular chain of do-it-yourself construction stores, to see what I could come up with. He also suggested looking into the vinyl-coated cabling that bike locks are made out of.

Success!

Home Depot carried a small enough gage of the plastic-coated wire rope to slip through the zipper where Kelty's nylon cord was. Creating a small loop on each zipper was done using an aluminum "Ferrule and Stop Set," crimping them with a special tool and cutting the excess off. Later a table-grinder was used to remove any protruding cable.

I pretty much got kicked out of the Home Depot, though. I was being bad and doing the entire assembly in the middle of the isle—using the wire-cutting machinery that was marked "for employee use only," as well as the US$30 crimping tool without purchasing it. But I didn't really see the point, as I'd use it in the parking lot and just return it away—and I needed the wire cutter.

I got a lot further than I expected—just one crimp away from completion before staff confronted me. …I just went to another Home Depot and finished the job.

Not only did I create these secure little loops of steel cable that I can run a padlock through, but I also used a larger gage of the stuff to create the cable I'll be using to secure my pack to something solid (so that it doesn't walk away without me), instead of the Pacsafe wire mesh I've been carrying around for my Moraine 3600.

Total cost for the homemade steel zipper loops (four) and one homemade security cable: US$5.13.

Comments:

Andy HoboTraveler.com

May 9th, 2007

Very Good,

The on the road version you can make by using them plastic wire management jobbies. I think the police also use them as handcuffs when they have hundreds of people.

Take the plastic, and a round ring or solid key ring and connect the same. Then you can alwasys bu a cheap dog chain when you forget your wire or it falls off.

Those plastic jobbies make good locks on bags in airports, however you need some fingernail clippers, not on the plane, but afterwards to cut them off.

I was thinking your idea would be good with two loops, one on each end like a big 8.

I think to buy crimpers here in Togo Africa would be difficult though. I will look for a Home Depot… hehehe

My one bag top was destroyed by friction in the motorcycle accident.

Find me a factory in Asia, and I will buy a few thousand perfect zippers to install in my chasing windmill backpack design. I think now I make bags in the Philippines, and buy the materials from Korea and China.

Andy, your friend in Togo, Africa with Chocolate Spice.
Andy of HoboTraveler.com

Ben

May 10th, 2007

You know you did your crimps wrong. I mean it doesn't matter cause they don't have to hold that much weight, but still, the crimps are wrong. LOL

Australia

Craig | travelvice.com

May 11th, 2007

Care to elaborate Ben? I know the diagram on the crimp kit said to feed the cable through opposite ends of the aluminum holder, but it seemed to be OK when done this way

Australia

Craig | travelvice.com

May 11th, 2007

Ahhh… Yes, Ben, I see what you're talking about; smooshed together from the wrong side.

I thought the crimps looked awfully weird when I did them, but they seemed ample strong/secure, so did them all in the same fashion. Well, at least they're consistently incorrect — it'll be our little secret. :)

Bill

July 16th, 2007

Looks like you found a great solution to an interesting problem. For others out there, replacing a zipper slider isn't that hard to do yourself. The difficult part is finding the locking zipper sliders. Detailed info on sliders can be found at http://zenbackpacking.net/ZipperSecurity.htm

Wade

February 27th, 2008

Howdy Craig,

Man, I knew that post would catch me a great idea. Thanks! Looking for the wires now.

Those Kelty backpacks are awesome, eh? I have never traveled with a pack so comfortable!

Thanks for this advice!

Wade
Vagabond Journey.com

Byron J. Gaudette

May 23rd, 2008

well done man! That part about getting kicked out of Home Depot had me cracking up, hahhaha. and I may have to go looking for a Kelty backpack, since everybody speaks so highly of them….

The United States

Tim Whitlow

February 11th, 2010

Craig, what gauge did you end up using for the smaller loops???

The United States

Craig | travelvice.com

February 11th, 2010

Wow Tim, I'm not sure — been nearly three years since I constructed them (but they're still working wonderfully). When I took the pack to Home Depot I pretty much just found the proper size for the zipper pulls.

Mexico

Tim Whitlow

March 25th, 2010

taking the bag to home depot would have been a great idea… lol I didnt but I just bought the smallest coated cable. Got all mine made and am now on my trip. Thanks for the help!!!

The United States

jonathan

October 18th, 2010

Hi, I know this is quite late, but what about the vulnerability of the interlocking teeth? I remember seeing a video of someone seperating the teeth with a ballpoint pen.

Here, I found something like it: http://www.youtube.com/watch?v=nKgz4sPk818

Is the zipper on your pack immune to this?

Peru

Craig | travelvice.com

October 18th, 2010

Not so late Jonathan, as I'm still using this backpack (and these zipper locks) today.

Yes, all zippers are prone to this. There's no solution, only zippers that are harder to get into (typically made of non-plastics).

Read more: Zipper Security and Lock Bumping

The United States

jonathan

October 19th, 2010

Oh wow, you're here! Congratulations on your marriage! (late again) I'm very glad for you.

So you already know about the zipper issue. I wonder if a top opening bag with a lock-able drawstring would offer a good solution. It would also require no zippered side-openings. But I think you prefer the panel loading style anyway because of the easier access.

Now I'm getting creative: do you think a style of pack with steel cable laces, or an opening which is closed by threading a cable in and out of eye-holes, and no zippers would be a good solution?

Then there's the steel Pelican cases. jaja. You have to balance satisfying your paranoia with practicality.

Peru

Craig | travelvice.com

October 19th, 2010

Sure, a military style duffel bag (photo) with metal eyelets and a steel cable (of your own design or maybe the Pacsafe Wrapsafe, if short enough) would be very much ideal from a security standpoint (cutting/slashing aside, unless made from Cordura or Spectra, which will stop or slow all but the sharpest blades)… but generally impractical and annoying from a long-term perspective.

Urban backpackers with top-loading packs will never know just how annoying their pack is until they switch to a panel-loading (aka side-loading) pack. IMO, the loss of security is worth the gain in practicality.

A little more reading can be done here: http://zenbackpacking.net/BackpackSecurity.htm

For my current travel lifestyle (now with wife and child), room security is more of an issue than ever, as we're consistently in private rooms, not shared living spaces (dorm rooms). It's easier for everyone to unpack some and keep the room locked down than keep a pack safe in a room with dubious security.

The United States

Rex

April 27th, 2011

1- If you keep a small lock on your zipper pull for an extended period of time, it will eventually wear away the loop in the zipper pull and break.

2- The caption for the first picture reading "insecure backpack zippers" should read "UNsecure," unless the zippers do not like their appearance.

Peru

Craig | travelvice.com

April 27th, 2011

@Rex:

1 - I've kept a lock on these for four years now with no damage to the loops.

2 - Unsecure isn't a word.
Insecure: not secure; exposed or liable to risk, loss, or danger: an insecure stock portfolio.

The United States

Rex

April 27th, 2011

1- I was speaking of my experience with a standard padlock slider from my Kelty backpack and a combination lock left on it for 5 years. Yours, however, looks much more durable.

2- Touche, salesman. I stand corrected

The United States

Rex

April 27th, 2011

And thanks for the insight and ideas.

I'm in the process of replacing the zipper from the above late 90's Kelty Sherman day pack.

Hopefully others will not repeat my mistake.

The United States

AC

May 29th, 2014

Thanks so much for this innovative solution. As I was searching for a new daypack not too many of them had the secure zipper with a lock.

Anyway, I am going to Ace Hardware with my backpack, cable, and stops to see if someone can help me do this. We do have a Home Depot that's 40 minutes away, so I will ahead there if Ace Hardware is a bust.

What was the standard size you cut the wire? I want them all to be large enough for most travel locks.

Thanks.

The United States

Craig | travelvice.com

June 4th, 2014

@AC - A bit smaller than the tip of my pinky finger.

The United States

Hizzo3

September 10th, 2014

Just wanted to say thanks to the idea. Worked well on my Kelty Flyway, my girlfriend's Eastpack, and my daypack - Deuter Speed Lite 20.
For those of you asking about of cable size. I used Black Nylon coated 7×7 1/16 Bare OD, 3/32 Coated OD and it worked well. I got this because I wanted black pulls on my tan bag. I also wanted clean crimping so I crimped all the way down, trimmed excess and filed off any sharp spots. The Eastpack could have taken a larger cable, but for the other two, the above listed worked perfect.
I used a thicker cable for attaching the bag to something, but after working with the cable used for the pulls, it could work too. Very flexible and has a 480 lbs break strength.

How to Make Backpack Zippers Lockable

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