Finished weight: 4.8 oz. (includes the shoulder strap system)
I will go ahead and admit that this day pack was partly inspired by Chris Zimmer's HalfPack 2.0.
Before I go into some details about this pack, there is a story about how I ended up making this day pack. A few years ago (before I got into MYOG) I got a Mountainsmith Tour Lumbar Pack. I loved the idea of the pack, and it was very comfortable, though very heavy for its size. Here is a picture of that pack.
Once I got into MYOG, I decided to modify that pack. I cut off everything except the hip belts and back panel. I made new panels, added an extension collar, added bigger water bottle pockets, and added a big mesh pocket. After all the modifications, the pack weighed 15 oz. Here is a picture of the Modified Mountainsmith Tour Lumbar pack.
For a while it was a great day lumbar pack, but once I got into Backpackinglight and MYOG, I wanted to make a new day pack that was much lighter.
A few months ago I had worked on a similar day lumbar pack as this 4.8 oz. day pack but was not satisfied with it. That original project started out as a lumbar pack, but it did not ride well (pulled back too much), and it weighed 9 oz. just for the pack without any shoulder straps. I added shoulder straps to that original day pack, and it still did not feel right. Pictured below was that original project.
I ended up cutting up that homemade lumbar pack, and I continued to use the modified Mountainsmith until I saw Chris Zimmer's HalfPack 2.0. It then dawned on me that I could remake the day pack I've been wanting and have it ride the way I want, which was mainly on my shoulders and with the back pulled up to keep it from bouncing.
I spent a couple of days obsessing over the details of the pack wanting to make it super light, and shortly after that, I was cutting up more fabric and sewing.
The main pack and pockets are 70D ripstop nylon. The bottom is 200D Oxford.
The shoulder straps are where I saved the most weight. I wanted the comfort of 3D Mesh and padding, so I only put the 3D Mesh and foam pad on the shoulder portion of the strap.
Also, instead of webbing, I used 3/16 flat nylon cord with LineLoc 3's to connect the shoulder straps to the pack.
I also sewed the 1/2" grosgrain sternum strap to the shoulder strap and eliminated the need for webbing on the shoulder straps.
Instead of a hip belt, I only sewed in some grosgrain loops, because I want the pack to ride mostly on my shoulders and use a cord belt to keep the pack from swinging. I may sew on 1/2" webbing with a buckle if I don't like the cord as a belt.
One big thing I found out after I made the pack was that the shoulder straps being connected to the black back panel was not needed at all. I originally had 1/2" webbing connected to the back panel from the shoulder straps, but when I pulled the pack up to the shoulder straps with the nylon cord load lifters, the webbing that was connected to the back panel was completely loose. I ended up cutting that webbing off the pack and shoulder straps and just left the nylon cord load lifters. Once I did that, the pack felt much better and it was now even lighter than I had planned.
In short, this new 4.8 oz. day pack is now the lightest and most comfortable day pack I have used, and I want to thank Chris Zimmer and his HalfPack 2.0 for inspiring me to make this pack after nearly giving up on day packs.