With a bit of spare time on my hands during the coronavirus lockdown, I found a way to turn an old running jacket into your own running bumbag. I had never owned one of these before, but they are perfect for carrying the essentials needed on a trail run in spring or summer.
What do you need?
– One rain coat that you no longer use, or two 29x24cm of lightweight non-stretchy fabric and a 26-30cm zip.
– 0.5m of strapping (35mm width recommended)
– 0.5m flat, wide elastic (35mm width recommended)
– Buckle, same width as strapping
– 1m of drawstring elastic (6mm width recommended)
– Toggle that fits drawstring
– Shoelace (optional)
Step 1: Measure and cut your fabrics
If you are using a jacket with intact zip, I would cut the front, back, top and bottom panel all out in one go. You can leave out the zip covers & remove the two seam allowances (3cm) from the dimensions in the image below (total cut-out size 45×29 cm) because the zip is already attached! Otherwise, follow the pattern that is stated. I used a different colour fabric for the back and top panel than the front and bottom panel, just because it looked fun. The 1.5cm seams were plenty of space for my “beginner” level sewing skills. As a handy guide, I marked the seam allowances with a pen on the back of the fabrics which helped when sewing everything together.
Step 2: Insert zip
If you used a cut-out from a jacket with the zip in the middle, you can skip this step. If not, first attach the zip covers and then sew the front and top panel onto the zip. You can use a zipper foot to get a neat stitch line, but it also worked with the default settings of my sewing machine. Use a normal linear stitch with short-to-medium stitch length.
Step 3: Attach the waist belt elastic
Take the outside of the back panel fabric (yes, the side that will be visible), and stitch a triangel of elastic onto it, see the image below. Keep the stitching within the 1.5 seam allowance which you will fold over when attaching the side panels. You won’t see these stitch lines in the final product so no need to be neat!
I have designed the triangel to give stability and make the bag fit flat on your back. The elastic means it is comfortable and moulds to your personal body shape.
Finally, stitch the bottom and back panel together to make a tube.
Step 4: Attach side panels
With the “tube” inside-out, attach the side panels. If you followed the dimensions, it should fit perfectly. I had to make a little cut out between back/top panel and front/bottom panel to make the corner fit, see picture. I found the sewing a bit tricky but even if it isn’t smooth, you will barely notice once you’ve turned the bag outside-out.
Step 5: Finalise waist belt
Take the non-stretch strapping, bum bag and buckle and measure the strap length around your waist. Leave enough room to get slimmer and bigger – I tend to tighten my pack halfway through a run, but you also want to leave plenty of space to wear the bag with lots of layers. Sew the strapping onto the elastic using a cross-shape, this should be really strong. The buckle usually has a built-in adjuster so just trim the strapping to the right length.
Step 6: Making elastic webbing
I designed this bag to have elastic webbing on the front so that it would reduce bouncing when not completely full – since you can cinch the bag down with the elastic. It also works as an “overflow” capacity – meaning you can stuff an item of clothing or map in the elastic webbing when the bag is already full. The webbing is optional, of course, but I feel like it adds to the functionality of bag.
First, attach four small loops on the side panels. The loops can be made from the elastic drawstring you’re using, or from an old shoe lace if you want extra colour pop. I would place them near the back panel so they can “flatten” the bag when needed. I hand-stitched these, so you can put the sewing machine away by now. When attached, simply weave the elastic through the loops as shown, and your up-cycled bumbag is done!
Now you’ve finished your bag, take it out for a trial run and show us your pictures! I found mine perfectly fitted all the mandatory race kit for fell races, although it will probably take a while before we get to try that out.