Detailed patterns:
.5" seams all around. 1" webbing for all straps. Quick releases WITH Tri-Glides. All 4 panels are 15.5" to the opening then they angle in toward the seat post. Begin your stitches in the difficult skinny section of the bag. I started with attaching my side panels to my top panels to make a large X with the four panels. I use staples rather than pins when sewing. I only staple the inner part of the seam to reduce holes in the exposed fabric. That is why a solid .5" seam is critical.
Side panels:
Top panels:
Use a piece of 1" webbing to space out your stitches for the "spine" of the bag.
I used 2 pieces of fabric and stitched them together at the skinny seat post area. You can use a single piece of fabric but I didn't have enough length in my piece of fabric. The benefit of sewing together 2 panels is the extra thickness at a high stress area. The downside is more possibility of allowing moisture in. I had zero issues with water and my first day with it on the bike was nothing but rainy and thunderstorms.
Strap anchors:
The strap will be sewn in-between the two folded pieces and there will be no raw exposed edges.
Seat post straps:
Very simple but effective.
Seat rail strap:
One side is fixed the other adjustable with a Tri-Glide. I cannot stress enough how important the Tri-glides are. Without them the bag will constantly loosen over rough terrain. Some might like dual sided adjustability and if I did it over I would have both sides adjustable.
I have a Fizik saddle which has a slot built in for different bags. This bag was not designed for that but I ended up using it because it added so much stability when riding.
But I made my "spine" webbing go too far back and it ripped out the first seam of the spine. After that I continued to use it with the strap through the saddle hole and had zero issues. The issue was that the strap was making an S turn and pulled the seam to the front of the saddle and ripped it out.
The seat post attachment was too perpendicular to the ground on this bag. It would be more difficult to make a pattern but I would prefer a steep angle at the bottom with a shallow angle at the top.
More like this:
However this bag molded to the shape very well and I had zero issues with leg rub. I mounted the front of the bag as low as I could to keep the weight down and toward the BB.
The mouth is very simple. I laid the bag out flat measured (twice) then cut the webbing. I gave myself 4.5" more than double the width of the mouth. Run the webbing through your buckles then sew it into a circle. Sew in your buckle fixed with no adjustment. Then I sewed the webbing to the bag like so.
I did not have a stiffener and it was fine. I am sure a stiffener would make it easier to roll but my sewing machine is pretty basic and I didn't want to mess anything up at the very end.
I bought all of my material from
http://diygearsupply.com except for the webbing which I got from Hobby Lobby. It's navy blue and looks DO matter.
I bought my buckles from REI.
I hope this helps someone because I searched high and low for a detailed bag plan and couldn't find any that I liked. I states at pictures of the AlpKit Koala for weeks before making a single cut. Remember, measure twice cut once.
If I left anything out please let me know so I can append it. This was all documented with my phone so typing all of this was tedious but I hope it helps someone.
Sent from my hammock
