Joseph Paetz – Final Documentation

For my final project I wanted to construct a harness to hold a commercially available dry bag under my seat. This would act as the seat pack in the line of bike bags I started last spring when I made a frame pack. My design was initially inspired by the Revelate Terrapin seat pack harness, but over the course of the design process I added unique features and visual elements. While I was designing the harness, I focused on ease of fabrication and matching the feel of my frame pack. To do this, I carried over several elements from my frame pack including the color scheme, the visual style of the mountains, and the use of blue paracord.

My material choices were mostly set from my frame pack. I used two water resistant fabrics for most of the piece: XPac X21 as my “main” fabric and a heavier Cordura as a second color and in any place that will receive a lot of wear (which turned out to be most of the harness). I also used a plastic sheet to make the side and bottom panels more rigid. For any part of the harness that contacted the bike I used a vinyl coated fabric to help reduce slipping. I also used normal webbing straps and hardware. The locations of these was mostly copied from the Terrapin.

When I started working on an initial mock up, I found the seam between the top and sides was very hard to sew because of how curved it was. Because of this, I decided to use grommets and lacing to connect these panels, which meant I only had to fabricate a flat piece. This element also called back to the lacing used to attach my frame pack. 

The biggest challenge at this point was figuring out how to fabricate the flat piece. I eventually settled on sewing most of the seams good side to good side and then flipping it inside out. I then had to go back to fold in and sew down areas I was not able to sew when it was inside out (because they would have made areas too narrow for the reversing step.

Throughout this project I realized the value of making lots of initial mock ups and tests. I was very strict about that for my frame pack, which made the fabrication process quite smooth. For this project I felt like I had less time, so I skipped some testing, but it just ended up costing me more time later. Also, A full mock up in muslin would have revealed some of the issues with the final version before I used the nice fabric. Currently the bag sways a lot when riding and the front of it is a bit too wide (and rubs against my legs when riding).