Project log for my organizer insert for Ortlieb Back Roller bike panniers.
I commute by bike, including a fair amount of shopping and errands, and I'm kind of obsessed with organization. I use some popular Ortlieb panniers, and I like to think I've committed to them as a "platform" for bike storage, long-term. I chose them because they're spacious, rugged and waterproof, but they're not made for organization. When fully loaded, I sometimes find myself dumping out all the contents to find something.
So, I thought an organizer insert, designed specifically for this bag, and specifically for the items I want to pull out of my bag most frequently, would make a good long-term project. What would that entail, exactly?
At a minimum:
- A laptop pocket, closest to the "bike-ward" side of the interior, just because it's broad and flat
- A place to hang my heavy U-lock
- Some kind of structural element to maintain a flat shape, and support the weight of the lock
Micro-optimizing? Sure, but I just like making things.
Some other nice-to-have features:
- A quick-release mount to attach to the interior of the Ortlieb bag
- Other, smaller, pockets or mounting points for other things, maybe wallet, keys, other bike gear
And, looking to the future, maybe other bags that:
- Compartmentalize and fill out the interior space of the Ortlieb bag
- Fold small and flat for storage in case I need the full volume of the bag
- Attach to each other in some clever way.
Overdesigning is fun; making a solid bag with places for the laptop and lock is my main goal right now.
v2: canvas, first version that actually works (2020/05/09)
v1: ripstop nylon, first minimally viable version (2020/02/25)
Having a decent idea what the pattern should be, it was now feasible to laser cut it. I cut these out:
- Nylon: 2x base, 2x tall, .5" seam margin
- Canvas: 2x base, 2x tall, 1" seam margin
I chose to start with an all-nylon bag. I realized later I might have used canvas for the outside and nylon for the inside. All-nylon was a good choice to start with though.
I sewed the nylon pieces together, knowing that it would be easier to sew the other bits on first, but not knowing exactly where to put them. The fabric was thin enough that I could manipulate it enough to sew things on later.
So here's what I did:
- Sew base A to tall A to make pocket A
- Sew base B to tall B to make pocket B
- Sew pocket A to pocket B
- Insert plastic pieces into pockets
- Pin velcro to both sides of each pocket (to ensure tight fit)
- Remove inserts and sew on velcro
- Find locations to attach lock strip, pin webbing in place
- Sew on lock strip
Whereas ideally I would have done step three last.
So everything generally works, but the lock is so heavy, it drags the fabric down too much, and it also puts a lot of stress on the webbing-fabric attachment (A single box x stitch). The strip needs more support, and fortunately the plastic insert can do exactly that.
v0.2: random scrap fabric, pattern test (2020/01/25)
After the cardboard prototype, I decided I was ready to take on the sewing project. I bought some off-the-shelf fabric that seemed appropriate, and then proceeded to think about how to make the thing for a few months. I spoke with some very helpful people at the Sew and Tell meetup, and finally accepted that I just need to try making it a few times. One of the suggestions was to make that first fabric prototype with cheap scrap fabric, so I tried that.
The design was based on the cardboard model, with two broad sides and a thin strip connecting them to give it some volume. I got one big design suggestion at the meetup that allowed me to make progress on this: each side should have a sealable pocket to contain the plastic insert. With that in mind, this first version allowed me to test cutting the pattern, and the sewing process. It turned out that this fabric was awful to work with (very stretchy and very ragged edges), but I definitely learned enough to gain the confidence to work on the next version, with the good fabric.
I was proud of myself for documenting my learning process with the first bag, but it was not that helpful afterward. I changed the design, and I've already internalized the lessons I learned about sewing techniques. Probably most significantly, I abandoned the side strip idea. A laptop fits inside the bag without that added width, and I had a hard time keeping the three pieces of fabric properly aligned. I might want to use a similar approach for a different project later.
- Began to understand how to think about designing the inside-out object.
- When my mental model of the inside-out object fails, I can pin fabric together and turn it inside out to test.
- When sewing around a corner, and you need to raise the foot to reposition the work piece, you can rotate it in either direction - it doesn't have to follow the direction of the seam.
- If I try the thin strip idea again in the future, I will cut it maybe four inches longer than needed, THEN sew it, then trim excess. That will fix half of the alignment problem, but still need to be sure that the two side pieces are lined up properly. It might be easier to use several smaller thin strips, but that would also be uglier.
- When cutting the pattern, following the curved corners isn't important: cut a polygonal hull, sew whatever seam you want, then trim. The seam doesn't even need to be curved, because the bag will take on an organic shape anyway.
- The four main parts are attached with three seams, and I put the third one in the wrong place, so the first two were unnecessarily exposed. It occurred to me that I could have just used a single seam, but having multiple seemed like a good idea anyway.
v0.1: cardboard and zip ties, proof-of-concept (2019/02/25)
My first attempt was a cardboard mockup, held together with zip ties. This worked well enough to prove the concept. It disintegrated after a month or so.
Latest prototype in action. The two main features driving the structural design are the laptop pocket and the U-lock strap. I'm a sewing beginner, and this is my first design, so I'm learning, making things up as I go, and I probably don't know a lot of terms that I should. Despite that, I'm very satisfied with this second iteration. It's truly usable, but I hope to refine it, so I'll point out a few issues.
It goes inside this popular Ortlieb pannier. I'm avoiding any permanent modifications to the waterproof exterior. Still figuring out mounting options, but that's not a major concern, because normally the bag is full enough to keep the organizer in place.
My three prototypes:
- Orange: random scrap fabric, to experiment with the basic pattern, not really usable
- Blue: random ripstop nylon (specs unknown, but it's .1mm thick). Includes a sewn-on nylon strap to hold the lock.
- Yellow: random canvas (.6mm thick). Includes a "through-the-frame" removable nylon strap+buckle to hold the lock.
Sewing the lock strap on the exterior, using this fabric, is not sturdy. U-locks are heavy, so it sags significantly.
Aside from the main pocket, each side has a mini-pocket just for storing a rigid plastic sheet to maintain the structure. I deliberately tucked the flap INSIDE the pocket rather than go over it. It made sense in my head, but it's clearly the wrong choice.
Trying to show detail of how the pockets are laid out.
Same idea for the yellow bag, but the flap closes over the pocket, and terminates on the outside of the bag rather than the inside. Much sturdier fabric, plus two velcro strips on the ends, instead of one in the middle, mean this bag holds its shape much more than the blue one.
Also shows the nylon strap going through the outer layer of the bag (via a "faced opening" made from the ripstop, and through the plastic frame.
This design allowed me to experiment with different insert combinations. There's plenty of weight to trim here.
Outside of the faced opening.
Detail of pocket layout
detail of pocket flap seam from outside
detail of pocket flap seam from inside
Detail of canvas inside-out.
Detail of nylon inside-out.
Making the shape template
Designing the fabric pattern was the first step. Since the Ortlieb bag includes a plastic insert to give it structure, using that exact shape seemed like the right way to go.
I took some rough measurements of the irregular hexagon shape. I could have used these to get pretty close to the right shape.
However, I have an unreasonable propensity for unnecessary accuracy. I removed the insert, photographed it against a grid, then transformed that photo into vector files for laser cutting. This is great for cutting the pattern from fabric in a repeatable way. Unfortunately I can't use the laser for the plastic insert itself, so I cut that with a dremel. In the future I might try a bandsaw instead.
This is a color-coded illustration of the pattern files I used.
- <span style="color:red">Red</style>: plastic insert
- Black: mounting hole cutouts
- Blue: "base" fabric pattern
- Green: "tall" fabric pattern, including the flap that covers the mini-pocket for the plastic insert.
I sewed these two fabric pieces together, repeated with another two, then sewed those two pairs together, then turned inside out. Adding velcro, slits, and hems was done at the appropriate steps.
The seam margin is .5" in this image, which is what I used for the orange and blue bags. The yellow one is 1".