The first stages of designing Kosumo.
Specs:
• Capacity: ~40-45l
• Weight: 450 gram / 1 lbs / 16 oz
• Why?
• What
• Inspiration
• Prototype One
• Prototype Two
Why?
I wanted a pack that perfectly fits my gear. My very first pack was the Osprey Aura 50, and ever since switching it out for a lighter pack on the Pacific Crest Trail, I still haven’t been able to find the right one. The Mountain Laurel Designs Prophet 48l (weighing 1 pound) was too ultralight for me, and I was pushing it at its upper weight limit. When it was too heavy with food, it was painful. When it was light, it was great and felt so free.
I switched it out for the Gossamer Gear Mariposa 60l (weighing less than 2 pounds) at the end of the desert section. Immediately it was more comfortable. The capacity was overkill and I didn’t much care for some of the features (such as the one long side pocket). On a more surface level, it was also grey. After the light grey Osprey pack, I was desperate for a colour that wasn’t grey.
What
A pack that is lightweight but still able to carry a bit of weight when needed. My base weight is around 12lbs (5.5kg) and I hike in areas that may require longer food carries. The pack needs to hold 5-7 days of food comfortably, and have the capability of holding around 10 days of food if needed. Carrying this weight I need a comfortable hip belt and shoulder straps, and a capacity of about 45l.
At first I thought the solution might be the Waymark Lite 50l pack. It ticked all the boxes compared to all the other packs available but it was a huge investment for something I couldn’t try on. The MLD Prophet ended up having a hip belt that didn’t cinch down enough and I was afraid of similar issues with regards to sizing.
I was still considering ordering the Waymark but ultimately I ran out of time. The lead time was several months and I wanted the pack for that Summer’s thru-hike. The solution was trying to make my own pack.
Inspiration
By now the 2020 lockdown had started and I was living in an AirBnb, with no job. I’d opted for temporary housing as I thought I was going to leave for a long hike anyways, but those dreams, like many others, were shattered. But it freed up my time to start designing my own pack. I didn’t have access to my gear and couldn’t design the pack around the things I need to carry. But I had my Gossamer Gear pack with me, and I asked my mother to measure the MLD Prophet which was hiding in their attic.
I started to pull together a huge spreadsheet with overall dimensions of gear manufacturer’s packs and the fabrics used by both cottage companies and MYOG enthusiasts. I spent hours researching fabrics and thread and foam. Nylon webbing? Polyamide? Polypropylene? What about foam? Cut up a yoga mat or get that elusive Evazote?
I started to list everything I needed, with different options from different companies from a variety of countries. I thought importing from the US was inevitable but after some time I realised I could get everything I needed from within Europe.
One element I couldn’t quite decide on was the optional internal frame. It would add a bit of weight but I was unsure of the gains. I looked into buying a pre-made frame from Gossamer Gear but didn’t like the idea of adding something I hadn’t made myself. I could construct something myself but in the end it just felt a little too messy and complicated for a first pack. Looking back, it wouldn’t have been the most difficult aspect of the pack build, but I don’t believe the improvement would’ve been significant.
Prototype One
Unfortunately my sewing machine was in an inaccessible storage unit on the other side of London so I got some wrapping paper from M&S, ordered some needles, thread and cheap cotton fabric, drew a pattern and cut the pieces.
The first prototype was simple. Much like most of the ultralight packs available and the ones people make online. It was a rectangular box, essentially. For a better fit I adjusted the width so it was a little narrower than the packs I owned, and tailored the torso length to mine (longer than the small Prophet, shorter than the medium Mariposa.) The shoulder straps were initially copied from the Mariposa and the hip belt was a basic straight band.
I hand-sewed the prototype together and tried it on. It was okay. I tried it a bit longer. It was horrible.
The boxy shape that suits most other people caused the load to push backwards and downward. It was wholly unsophisticated. The straps didn’t really attach right and the hip belt was too straight.
Prototype Two
I took the first prototype and noted everything that should alter from the rectangular shape:
• Taper the pack so it’s narrower at the bottom and wider at the top. Both side panels and front panel are tapered by 15mm, effectively tapering the pack by 60mm altogether.
• Angle the bottom panel up by 40mm, for better load distribution (and adjust the side panels to suit.)
• Curve the hip belt along my hips. After changing this, I wasn’t sure how I ever used a straight hip belt. I also made the sleeve narrower on the back panel so the hip belt was able to cinch better
• Bigger side pockets.
• Curve shoulder straps. This took some time to get right. First I attached them at an angle but they still didn’t sit right. I decided to alter the straps to an S-shape, which is supposed to fit women better. I made new straps but they fit even worse. I then cut the straps up, slowly adjusting them back to a J-shape until they seemed to fit best. The straps ultimately attached to the pack very low, rising up to curve around my shoulders. This seemed odd, but gave the best fit. It means the shoulders straps are a little longer than usual.
• Added load lifters.
• Lastly I took a pencil and drew any small changes that didn’t need to be prototyped again on the new pack. Slightly higher side pockets, locations of compression straps, the front pocket etc.
When I was happy I counted all the buckles and ladderlocs I needed, decided the width of webbing I wanted everywhere, and placed my orders. This was slightly terrifying, and it wasn’t cheap. I spent 150 EUR at Extrem Textil and Adventure Xpert (but I do have some leftover fabric after finishing the pack.)
I received my orders but without my sewing machine, had to put the build on hold. It took a few months before I’d rented a room and got my things out of storage. When I resumed, I decided to film the process. Talking to a camera at 7 in the morning is very odd but I got a lot of inspiration from reading and watching other people make their packs, so I decided to share my process as well. You can watch the video on the main MYOG page.
The next post discusses the pack build and my review after using it.
3 Responses
Hi ya Rosanna, So good to see such a well thought out pack design from start to finish. Your calm design process is such a joy to watch and so easy to follow. Ive make a few packs in my little studio on the west coast of Australia. If you ever get out this way in the future, then feel free to look me up. There is a long walking track that runs from Perth to Albany (600 km) called the Bibbllmun track in the south west corner of Western Australia. Ive only done little bits of it over the years, though im sure that it would be just your type of thing. Keep up the nice work. Would love to see you do a tent and a quilt next.. No pressure. See you Dave
Hi David, so glad you enjoyed it! Making packs is fun isn’t it? One of my next projects is indeed a tent although the prototyping stage is proving to be very daunting because the whole thing is just so big and I’m finding myself designing more packs instead haha. But I have all the materials so it’s definitely coming. Also, the Bibbilmun track is definitely on my list! It sounds like a great walk.
Hi Rosanna, where did you get the graph paper for your prototyping? Was it a large sheet or did you just tape smaller sheets? Thanks!