2nd Attempt, a respectable backpack at 14.07 ounces

@mikejones3-2 That back zipper is wild. I haven’t seen that before. What’s your thinking on putting it there vs on the front?

Nice color combo with the red and black and innovative zipper design too. Single seams have worked well for me, especially if there’s reinforcing in key areas of the pack. Reinforcing with bar tacks, flat felled seams, multiple rows of stitching, or x-boxes all work well depending on location, such as where the shoulder straps and waist bet attach and at all points of stress, like hull loops. I always sew a second line of stitches close to the primary just in case the primary fails too, just in case.

Cool pack! Thanks for sharing the construction pictures.

Did you consider having the zipper flipped, so that it opens from the bottom?

@mikejones3-2 That back zipper is wild. I haven’t seen that before. What’s your thinking on putting it there vs on the front?

I like roll tops because they can get bigger or smaller depending on what kind of adventure you are going on. The one problem is a rolltop has no quick entry into the pack itself. So for a photographer like myself, the zipper adds a quick entry to be able to take out lenses and swap camera gear on the fly. The Zipper on the back also provides security because no one can un-zip it while it’s on my back and pickpocket my gear out. I have a Peak Design Travel backpack with the rear entry and loved it but wanted a much lighter backpack.

Did you consider having the zipper flipped, so that it opens from the bottom?

I did but I figured with the zipper sitting at the bottom it may hurt my back and be more prone to leaking when raining.

The zipper at the top is actually kind of cool if you think about it. I slowly unzip it down while I roll the roll top down. So when its rolled down the roll is actually just over the zipper so it protects rain or anything from getting in, but I can also easily pull it down to get inside and zip it back up without undoing the roll. Think of the roll as almost a big zipper garage. If that still doesn’t make sense I can try and take another picture to show this.

If you can handle a few grams more, THREE zipper sliders would let you put a pair of facing sliders in the middle of the zip, so you can leave the top zipped together when you roll shut, and then have a pair that can open in the middle of the panel, which you would keep parked just below the roll when closed.

Great work!

If you can handle a few grams more, THREE zipper sliders would let you put a pair of facing sliders in the middle of the zip, so you can leave the top zipped together when you roll shut, and then have a pair that can open in the middle of the panel, which you would keep parked just below the roll when closed.

Oooo, that’s a really interesting idea… I may look into this, I am already planning pack #3….

After pack #1 I was like this is super tedious I never want to do this again. Then after pack #2 I am like this is awesome I cant wait to start the next one. Each one has minor tweaks lol

Right now I am debating whether I want to use LS07 again or go to LS21? I also still need to see how I want to tape this guy in the inside… I am thinking cuben fiber tape?

Then after pack #2 I am like this is awesome I cant wait to start the next one. Each one has minor tweaks lol

I’m just starting on the 2nd iteration of my first pack design—going from a Tyvek prototype to Robic 420. I haven’t even got a usable version done yet (much less taken one on the trail…who knows when, right?), and I’m already dreaming of other pack designs.

Super fun but not a big budget saving hobby!

When I was leading trips, I liked having a panel-loader pack (continuous zipper on 3 sides of the back panel) because I never knew what the clients would need during the day – you could lay the pack flat, unzip the back panel and see it all before you.  Your centered zipper is a very nice way to get most of that access with less zipper length, resulting in less water entry while maintaining the variable volume of a roll top.

Glad you like it! I hope to one day make a larger version like 50-60L with a back center zipper for long trips.

I am just not confident my stitches to hold all the main pack panels will hold since I am just using a straight stitch for those seams at this time.

The zipper down the back seems like a very functional idea to use it as an EDC/duffle. I tried a few different bags out and didn’t quite find a duffle/backpack combo that I liked that I could use for EDC for laptop and papers, gym clothes, lunch, etc. so I just went with a backpack.

Very nice job!

Would you even need the top of the zipper to come apart (3rd slider), or could you only use 2 facing sliders to be able to open in the middle?

I like that design. A very innovative coming from the standard (and very functional) pack design everyone else makes. You may have already decided but for that design where tyou may be opening it like a duffle and laying on the fabric, I would go with ls21 for sure over ls07.

Not sure if cuben tape will stick so well on the dwr backside of liteskin but let us know! It may very well work enough for sealing but certainly not adding much sheer strength.

Nice pack Mike.  I use the same zipper arrangement (but on the front) for big load hauling packs.  It’s a nice clean way to create easy access, and I’ve had really good luck with zipper longevity for myself and customers.

Strength with a straight seam has more to do with fabric, thread, needle, and stitch length choice working in concert than anything else.  HMG used to use straight seams on the back/side interface of all of their packs, but due to the properties of cuben laminate had major issues with the stitch holes stretching and exposing the stitching over time.  They went to a felled seam ~3 years ago, which addresses the hole stretch issue (at the cost of having an external stitch line which can abrade.  I imagine those seams are quite the pain to sew, too.

I use heavy (Tex 90) thread in all my packs, and a tight (2mm) stitch spacing on vertical main seams.  On the heavier fabrics I use such a seam is immensely strong.  On the fabrics you’re using you probably couldn’t get away with my approach, hole stretch and potentially having the fabric rip along the seam line might eventually be an issue.  Felling the seams would get around that, with other downsides as mentioned above.

Personally I don’t build with light laminate fabrics anymore.  Too many downsides for modest weight savings.

Yeah, definitely a convenient design for easy access.  Be aware however that you give up quite a bit of ‘containment’ or ‘stuffability’ strength with the zipper cutting through one of the main panels like that.  As you stuff the pack fuller from the open roll top to compress the contents, the zipper will be subject to a big tensile load and be the first thing to pull apart if you go too far.  You can see the same thing happen on tent vestibule doors that are drawn together with a zipper.  Eventually the zipper is always the thing that fails first.  If you’re always careful however, you should be able to stay within the mechanical limits of the zipper.  Or size up a bit to get a little more strength like with a #5 or #7 zipper.  Even those will have a far lower limit than your base fabric though.  Good job on completing another successful project though!