Customized Bicycle Ditty Bag

Bike bags are great.  Problem is, my road bike is a rather odd shape and many of the common saddle and storage bags to carry a small pump, spare tire, tools etc, will not fit on the bike in a desirable spot. In addition, sewing a customized bag of your own is much cheaper and infinitely more fun!

This instructable will walk you through the steps to making a storage bag to strap to your bike. I believe that while this project is relatively simple, dedication to small details in the planning and construction of your bag will result in a great looking bag that matches the quality of nearly any bag on the market. 

Here I will divulge what I learned, mistakes that I made, and possible improvements to the art of sewing your own bike bag.

Step 1 Design

This is probably the most important step. Determine where you think that a bag would best serve its purpose without interfering with riding or other components of the bike. The type of riding you do will also impact your design. If you race, there's a really good chance you'll keep it simple and minimal. If you mostly just go on leisurely cruises, you can afford to be more experimental and innovative.

Here's my train of thought. My bike frame is extremely tall and I prefer to have my seat positioned more forward which eliminates the possibility for me to simply buy a saddle bag and strap it to the underside of my seat. I also didn't want to have a storage bag on the front side of the seat post so that I might add an additional water bottle holder there.

Because my frame is so tall, there is a large amount of space between the seat post, tire and seat stays. I determined that this would be an ideal spot for my bike bag since it is out of the way and will introduce a minimal amount of extra drag. The only problem I saw with this location is that it will see a lot of spray from the tire during wet riding conditions.

Once you have your location picked out, measure the dimensions and relative angles on the frame. Be careful when considering the width of your bag. Once completed the fabric can easily bulge at the sides and seem much wider than you might have intended. If you race that can be bad, but if the bag is for a cruiser it won't matter that much.

Next consider the opening. How big, long, where and by what means? A zipper is obviously a great choice, but don't forget about velcro or just be creative. Keep in mind that if it somehow comes open during a ride, you REALLY don't want your stuff falling out!

Another key to your design is the attachment mechanism. This has to work in coordination with your opening i.e. they can't effectively overlap. Racers: the smaller and lighter = the better. Cruisers: anything goes. Rope, straps, buckles, magnets*, anything! 

* I think it'd be really cool to sew some magnets into the fabric and have it appear to just "float" on the bike!

Fabric is the last consideration. Your type of riding and typical riding conditions will help with this decision. Here are some of the big differences in fabric that you should consider: weight, drag (smoothness), strength, water resistance. 

So you have the location, size and shape of your bag picked out. Now you'll take that and break it down for sewing. There are many ways to do this, but here's how I like to do it. 

Treat your bag as if it were a rigid object and evaluate each geometric shape. Mine happened to be mostly triangular. Draw them on a sheet of paper. Instead of cutting out each geometric shape and sewing them together, butt some of the common ends together and just fold there. This involves less sewing and therefore a better similarity to the original design. I broke my bag down into two separate pieces. One piece comprised both side triangles and the front (attached to the seat tube) while the other piece was the bottom and rear (opening) face.

Comments

[dyoder]

ok that bag is amazing i had plans last summer making one had a friend make one ended up being to big looks like u have the right idea i was pretty close on getting it right an its amazing when to completly diffent people come up with the same idea that have never met great job on urs i thing that location of a bag is perfict its out of the way an kinda hidden reminds me of a motor cycles oil pan

[struckbyanarrow]

what size is that frame man? 64cm? you did an excellent job on the bag.

[B4SEC4MP]

It's actually closer to 66cm! I had a near miss the first time I dismounted and tried to straddle it. Haha. I have to stand on my toes. Thanks for the compliment.

[struckbyanarrow]

how tall are you? i really like the look of big 62 cm+ lugged frames, being 5'10" I cant fit on one, haha

[it_dont_work]

nice bag, you could also use it as a headset bag if it didnt fit smaller frames. and did that head on crash hurt? thoe forksare mangled

[B4SEC4MP]

Wow you're good! I got the bike (or what was left of it) for free. It was abandoned at a bike rack all winter and really beat up. I had to replace several components but the frame and forks looked square to me and it rides fine. What gave it away?

[it_dont_work]

well it should be straight inline with the head tube before the fork curves forward. after a head on crash they tend to make more of an s kind of shape like yours. it could very well still handle well being such a long wheel base and large frame, i dare say it looks like it'd be twitchy at high speed. just go's to show how strong the old steel frames are.

[B4SEC4MP]

After everyone noticed the mangled forks, I used Photoshop to gauge the amount of trail left and it's basically nonexistent. Haha. I think your right, because the wheel base is so long my weight is far enough back to ride alright. I knew the steering was tight, but I didn't realize it was because the forks were bent back since they're still square. Part of me wants to bend them out just a bit, but I don't think I can bring myself to risk it.

[it_dont_work]

well it is steel so it has some flex. you can cold set frames and forks. look up sheldon brown's guide on google. i dont reccomend it tho, a new set of forks can be as little as 50 bucks, trouble is finding threded forks long enough

[nickjohnson]

Looks like you bent your fork back in an accident. Might be hard to find a replacement for such a tall frame.

[Archergal52]

Cool idea, but honestly my first thought was "That's a HUGE bike!" :)

[f3rg]

It's a great project, unless you ride a smaller 53cm (or even smaller than that) frame, in which case the bag would be so small that it'd mostly be useless. It must be nice to be tall. :(