Do-it-Yourself Laptop Computer Pannier

That's a "saddle bag" to many of you. ;-)

I use this homemade bag for commuting to and from work, about 4 miles over average city streets. My computer remains intact, and with careful construction, yours should too! In addition you get the pride that comes with building your own bag, and not giving $100+ to our fine friends at Land's End. For the record, however, I would like to state that theirs is no-doubt better and more secure than this piece of crap.

...But I like to build things.

UPDATE AVAILABLE! After much wear and tear, this bag's Achille's heal showed itself. A fix is provided at the bottom of the page. Don't build without reading the update.

• $20 computer bag from Office Max
• 26g steel plate (12x18") from Lowe's
• 4 mirror brackets from Lowe's
• Pop rivet& washers
• Black paint (Rustoleum)
• Carabiner
• Hook
• Luggage or trunk strap

• Total cost: around $30

1. Place the computer bag on top of the steel plate, and trace out the shape of the bag bottom using a black marker.
2. Cut out the curved shape of the bag bottom using STRONG snips. 26g steel is reasonably tough.
3. Knock off sharp edges using a file.
   

1. Insert the steel plate all the way into the back "document pouch" of the bag.
2. Draw a line across the top of the pouch.... the plate is shown here partially withdrawn from the pouch so you can see the line.
3. Cut along the line, and knock off the edges as before.
4. Paint the steel to keep it from rusting.

1. Hold the bag along side your rack. Make sure it clears the brakes.
2. Mark where the crossbars are on the rack, as well as the front and back of the rack.
3. These marks indicate approximately where the brackets belong... make sure you mark a little off-center of the crossbars, or your brackets will hit them right in the middle. :-(
4. NOTE: Make sure brackets span the entire width of the bag. This will allow mounting on either side of the bike.

1. Cram the steel plate all the way into the pouch.
2. Use an awl to punch through the fabric at your marks, and scratch the paint.
3. NOTE: The picture at left shows the plate pulled out of the pouch a bit so you can see two of the marks.
4. Your brackets (shown in the bottom pic) will have at least two holes... mark for both of them. I put the top mark 0.5" from the top, and the second one 1" from the top, to match my brackets.
5. The thingy to the left of the bracket is a pop rivet. You will next be drilling holes through the steel plate to accept the rivet.

1. Drill a hole at each of your marks... through the PLATE ONLY! Don't drill through the fabric.
2. I used four brackets, each with two holes... hence the 8 holes at the top of my plate.
3. I drilled an additional two holes at the bottom corners. Rivets will go there for added support.

1. Insert the steel plate all the way into the back "document pouch." I mean it... ALL the way in!
2. Use your trusty awl to punch through the bag and the holes you made.
3. Work one bracket position at a time, beginning with the middle ones... the brackets that will be physically behind the computer when it's in the bag.
4. Really worm that awl around... spread out the fabric liberally.

1. Whip out your trusty rivet gun! Public decency laws prohibit doing this in public.
2. Place your brackets between the steel plate and the fabric.
3. Insert a pop rivet through the holes (washer-fabric-bracket-steel).
4. Operate the rivet gun as specified by the manufacturer to "pop" it.
5. Two rivets later, you have something like what is shown here.
6. NOTE: For the center holes... those directly behind the computer... use SHORT rivets.
7. NOTE: Using rivet washers against the fabric makes the connection stronger.
8. Do the other bracket that's behind the computer.

NOW we get VIOLENT! Two of your brackets should lay beyond the ends of the compuer "pouch" inside the bag. In these locations we'll put the rivets all the way through the back of the bag for SUPER strength.

1. Using the awl, punch all the way through the document pouch, the holes in the steel plate, and the interior of the bag.
2. Worm, worm WORM the awl around, or you won't be able to get the rivets through.
3. Insert a rivet, this time in the order (fabric-bracket-plate-fabric-washer). That is, the washer will be on the inside of the bag, but OUTSIDE the area occupied by the computer.
4. Pop away! Remember to do the two holes in the lower corners too, sans brackets.
5. NOTE: Use longer rivets for these holes.

When you're done riveting, the back of the bag should look something like this.

I tried a couple of ways of strapping the bag to the rack.... and the strap shown in the "parts" photo didn't work especially well.

I ended up using a funky strap found in a "Tractor Supply" store, though in principle any similar trunk or luggage strap would do.

1. I removed the original ends from the strap.
2. One end was replaced with a carabiner. (top in photo)
3. The other end was replaced with a funky "clip." It has a swivel, and while normally closes into a ring, it's jaws open with a thumb press. Not always needed, but handy for low-rider mounting.
4. The carabiner attaches to the top of the rack, and the funky clip to the bottom.
5. Pull the strap tight, et voila!

No... it's not.

However, after a number of trips with the bag, one of the brackes has bent slightly. It doesn't affect its performance. (Ok, eventually it did. See update below.)

Mirror brackets aren't the greatest choice for this bag... they are too shallow, and if the strap isn't REALLY tight, the bag can be bounced off the rack. In the future, I will probably bend some steel bar to make deeper, stiffer brackets. I wanted to show the "off the shelf" approach first, though.

I also recommend riding with this pannier on your low riders, rather than the rear rack. Three reasons:

1. The front gets a smoother ride, free of "wobble."
2. Putting a heavy laptop like mine on the rear rack really destabilizes the bike.
3. You can see your precious cargo, and avert disaster should the mounting fail.

UPDATE: Mirror brackets bite the dust

Ok, the mirror brackets just didn't hold up. The bending you see above got worse and worse and worse... made for a dangerous situation. After combing Lowes for something better to use, and leaving empty-handed, I decided for a custom solution, shown below. I drilled out the rivets holding the center two mirror brackets, and made two heavy-duty replacements.

1. I purchased a length of steel bar, 3/4" wide (but I don't recall the thickness).
2. I used a MAPI gas torch to heat the bar end to its plastic point (top left). Propane should work fine... MAPI just gets you there faster.
3. I had previously chosen a metal piece to bend the steel bar around - something slightly larger in diameter than the aluminum bar forming the bike rack. In this case, I used a steel drill-bit extension (middle-left). I used a channel-lock and hammer to bend the hot steel around the drill extension. The top-right photo shows it bent and still red-hot. Quench the hot steel in water.
4. I cut the pieces to a reasonable length and brushed off the oxidation (middle-right).
5. I drilled a pair of holes to match the original spacing of the holes in the mirror brackets.
6. Finally, I gave the curved part a single coat of Plasti-coat, and hung them on a coat-hanger rack to dry.