Introduction: Trail Approved Saddle Bag for Bikepacking

In this instructable i want to share a quick solution to build a saddle bag that is robust enough to ride a full suspension mountain bike on moderate trails and large enough to pack approx. 7 litres and hold at least 2kg.... thats 4.4 pounds for you Americans, greetings from Germany ;-)

I was bikebacking last week for the first time and did not have a saddle bag. While packing my stuff I was not happy at all with the weight of my backpack and therefore decided to try to quickly build a saddle bag. The result was quite good and exceeded my expectations by far. In fact the bag by a very known bike brand that my collegeague had for this trip was dangling much worse than my construct. Therefore i encourage you to try and build this. It is easy and a lot of fun to build.

You will need:

  • a sheet of 3mm thick ABS, approx. 40 x 15 cm (~16 x 6")
    (i had one left from building skis)
  • 3 tension belts of approx 75cm (30") length
  • 2 velcro straps oc approx 15 cm (6")
  • 1 paracord of approx 30cm (12")
  • a duffle bag, preferably waterproof, of approx. 45 cm (17.7") length and 14 cm (5.5") diameter
    (i used one from Decathlon in which the tarp originally came)
  • a metal ring, e.g. a key ring (will also work without but the ring helps a bit)

Required tools:

  • a saw. Almost any saw will do, i used a jigsaw.
  • a drill with 4mm (0.16") diameter
  • a small file to clean up the cuts in the ABS sheet
  • a bit of sand paper to clean the cut edges


I only bought the belts which cost me ~9€ (A bit expensive, you can find cheaper ones, but i wanted them with metal buckles.) everything else i still had at home. If you have to buy all: a bag 5-20€, the ABS sheet 5€ and velcro straps 2€ you can still get away under 20-25€. (~30$)

Step 1: Cut the ABS Sheet to Size and Drill Holes

Use the saw to cut the ABS sheet to size. Then use a bit of sand paper to smoothen the edges.

I cut it freestyle by simply measuring the width of my saddle and the width of the duffle bag. But for this insctructable i measured the shape and attached the sketch so you can get the exact shape.

If you use a very thin or brad saddle you might adjust the shape a bit.

Drill the needed holes as shown in the pictures. For each opening I drilled a few holes next to each other and then used a small file to get the rectangular shape of the openings.

Step 2: Attach the Velcro Straps

Attach the two velcro straps. Here you should be aware that the soft side of the straps is facing the seat post if you dont want to ruin it.

Therefore the first velcro strap should have the soft side on the outside while the second one, that actually goes around the seat post, should have the soft side on the inside!

Step 3: Attach the Tension Belts and Paracord

Run the first belt through the two openings next to the velcro straps.

Then run the second one to the next two openings.

The final one goes only throug the opening at the back.

I attached a piece of paracord to the second and third belt to hold the bag a bit better to the sides. You can also do this later and try without it first.

I also used a key ring to get a "Y"-shape into the last belt.

Step 4: Attach the Bag Holder to the Bike

It is a bit tricky to explan this therefore i took a lot of pictures and tried to sketch it.

  1. First attach the velcro straps to your seat post. (check again that the soft side is facing the post)
  2. The first belt is the hardest to explain. It first goes up to the bars holding the saddle but then down and below the velcro straps. Then up again and to the other side. So if you pull this belt it will also pull the sheet ant the velcro straps up to the saddle.
  3. The second belt just goes up and through between bars and saddle.
  4. Attach your duffle bag
  5. The last belt goes up and also through between bars and saddle. To reduce the spread of this belt i used a key ring to keep the back-and forth-going sides close to each other.
  6. Then attach the paracord to reduce sideway movement of the bag as needed.

Step 5: Have Fun

Thats all. The bag worked perfectly for not too heavy trails and you can even use a dropper post. The travel of my rock shox reverb was reduced by approx. 3cm (~1.2") and of course the saddle will go up slower than usual due to the higher weight. The only thing i will change is the bag itself to a waterproof bag.

I hope you like this insctructable and i would love to see if anybody uses it to build a comparable set-up.

If you do so let me know! Happy trails and travels!