Do you need a little extra cargo space for your city bike or day bike? How about creating your own small saddlebag for general riding duties? Inspired by making use of scraps and offcuts, Mike shares a step-by-step process to make your own, easily modified to suit your needs and the materials you have to hand.
I’m quite a big fan of the traditional zip-roll style of saddle bag for general riding around duties. The form factor is good for carrying essentials like a mini-pump, rain jacket, tools, spare tube, snacks, wallet, phone and so on. The slightly retro appearance is also a good thing in my opinion, with the only caveat being that you need some bag loops on your saddle.
Originally this project came about because my Carradice Zip Roll was on its last legs after a few years of use. It’s been consistently used in damp, gritty environments and despite regular waxing the cotton canvas does suffer eventually. It has holes in it now at wear points and the canvas no longer has the stiffness to hold any kind of shape, rather it hangs like a sad old, deflated and faded balloon. This DIY example is made from cordura and as such has better tolerance to being used in a muddy, gritty environment without any kind of fabric care. It is also really cheap.
I’m very much in the habit of keeping materials and parts scavenged from worn out gear as well as all the offcuts from other sewing projects as I make gear for my bike. The first instance of this bag was substantially made from offcuts and recycled elements from under the workbench. This second one I made, illustrated here, by contrast contains a greater proportion of new materials; even so it still cost no more than a few £ to put together. As I go through I’ll highlight where you can use alternatives and scraps. It is also important to note that I’m not claiming this as a definitive approach to making such a bag. I’m sure it could be improved or done differently but at least it gives you a starting point to making something similar.
Size and Saddle Fit
The dimensions listed will make a bag roughly 10″ (254mm) wide by 5.5″ (140mm) diameter with attachment points suited to my Brooks Cambium C17 saddle.
There are many different makes and models of saddles with integral bag loops, or you might be using accessory loops bolted to your saddle rails. Further, my seatpost is a zero-setback while yours may well not be. So if you’re making this bag for a different saddle to the Cambium C17 then here are a few things you should do to check the measurements:
1. Measure the distance between the centers of the bag loops on your saddle, then wherever I have mentioned the distance between mounting hole centers below, in my case 4 1/2″, substitute your measurement.
2. To make sure the webbing loop for attaching to the seatpost is in the right place, if making a bag of the same rough diameter in cross section as this one, then you can just cut a paper circle of the same diameter, offer it up below your saddle and mark the points at which it touches the bottom of the bag loops, and its closest approach to the seatpost itself. Measure around the circumference between the two marks and use that to locate the position, relative to the hole centers, of the middle of the webbing loop you will sew on. I recommend making this loop at least a couple of inches long so that you have some leeway.
3. The bag has a wear patch sewn on to protect contact points – at a mimimum the bag loops may cause wear, and if the bag touches the sides of the saddle, or part of the seatpost mounting bolt then further wear could occur. In my case to determine the size of the wear patch I measured the widest point of the rear of the saddle and, using a paper template, made an estimate of how far fore and aft of the bag loops it ought to extend. For the C17 on a zero-setback post 7″ x 3″ (178mm x 75mm) seems to work well with 2″ (50mm) forward of the bag loops and 1″ (25mm) aft. If you think you need a different sized patch then substitute those measurements in the instructions that follow for making the wear patch. Be generous with your measurements if unsure; I think the wear patch adds a degree of sophistication to the appearance of the bag.
No templates are required to make this bag, it is of very simple construction. Note that while I usually work in metric units there is something qualitatively ‘useful’ about imperial measurements when sewing. I find it easier to work with 1/4″, 1/2″ and so on than 6mm, 12mm etc when putting together bags like this. The coarse imperial divisions on a steel rule are also particularly easy to work with visually, especially if you might need glasses for close work. For that reason everything that follows uses inches as a primary measurement with the millimeter equivalent in brackets, except where I used material originally specified in millimeters, such as the support dowel. If you wish to use millimeters instead of inches you have lots of leeway for rounding up and down and might as well round to nearest 5 or 10mm.
Materials and Tools
I’ve listed pieces of material separately as you may be using scraps or material scavenged from old duffel bags and the like.
- Main body: you need a rectangular piece of cordura 11″ x 17″ (279mm x 432mm). 500, 600, or 1000 denier fabrics should be fine. The 11″ width will give you a bag 10″ (250mm) wide with a 1/2″ (12mm) seam allowance. For this I bought some seconds-quality 600 denier cordura fabric from eBay for not very much – it has some markings on the back. 1.5sqm, enough for many projects, cost £6. You can often find roll-ends or seconds quality material for very cheap.
- Sides: these will be cut from a piece of the same, or similar, material roughly 14″ x 7″ (356mm x178mm). Do not mark or cut the side pieces at this stage, until you’ve joined the body into a loop.
- Zipper ends: You need a further 2 scraps of the same or similar material roughly 1.5″ x 2.5″ (38mm x 64mm) to make the zipper ‘garages’.
- Wear patch: Contact points with the saddle may wear over time so a piece of heavier duty fabric as a wear patch is a good idea. This needs to be 7″ x 3″ (178mm x 75mm) for my Cambium C17. I used a piece of rubberized nylon fabric that was once part of the back-system of a no-longer-fit-for-use backpack. Another good choice would be scrap of coated vinyl fabric for example. Anything that’s durable and won’t fray too badly when cut – or that could be sealed around the edges with a flame or soldering iron for example.
- Zipper: You need a 10″ (254mm) piece of zipper intended for closed end applications. The first bag I made used some YKK waterproof zipper left over from another project. I’m not convinced waterproof zipper is worth the cost if buying new; I suspect it could degrade quite quickly in a gritty, muddy environment. For this example here I picked up a length of delrin zipper and a bunch of sliders off ebay for £2. Enough for 4 or 5 bag projects. The delrin teeth are more durable than a conventional coil zip and have reasonable water resistance. Look for a zipper around 1/4″ wide (5mm or 6mm wide) across the teeth when closed. Note that zippers are another thing I’m happy to unpick and re-use from knackered gear if still in good condition.
- Webbing: A piece of 1″ (25mm) polyester or nylon webbing, 3″ (75mm) long. I used a piece from that old backpack.
- Velcro: for attaching the bag to the saddle and seatpost I used a length of 1″ (25mm) wide ‘One-wrap’ velcro cut down to about 3/4″ (20mm) in width. It’s generally sold by the meter or imperial equivalent so if buying new look for some 20mm or 3/4″ wide stuff and just buy a couple of feet or a meter of it. It is incredibly useful stuff so any you have left over I doubt that it will be wasted.
- Bag support part 1: Support Dowel: Inside the bag you need a length of dowel or similar. I used some leftover 20mm PVC waste pipe I had in the garage. A wooden dowel, bamboo cane, or bit of old fishing rod blank for example would all work well.
- Bag support part 2: Support Stiffener: To help give the bag some shape where it hangs over the dowel you need a piece of ‘something’ flexible roughly 10″ x 3″ (250mm x 75mm). The first bag I made used a piece of stiff, closed-cell foam from inside the same backpack mentioned above. This version uses a piece of 0.5mm thickness polypropylene sheet cut from the end of an A4 sheet of the stuff. It’s not fully 10″ wide but it doesn’t matter if it does not quite extend the full width of the bag. You could probably make this piece from a large soda/pop bottle I think. I don’t drink the stuff and it’s two weeks to the next recycling collection so I wasn’t able to scavenge anything from my neighbours recycling bins…
- Thread: I’ve been using Coats Nylbond for all my DIY gear. It’s a very strong bonded nylon thread that I’ve found to run very smoothly through my machine and fabrics without snagging. Anything of that sort should be fine.
- Sewing machine: A domestic machine should be fine for this. I’ve been using a 90/14 needle. I’m no expert but it seems to play well with the thread mentioned above and a variety of heavier outdoor fabrics such as cordura and VX21.
- Steel rule
- Scissors and/or sharp knife – scalpel or stanley knife. I have a Swann-Morton scalpel with a number 10a blade that I find brilliant for this sort of work.
- Chalk pencils are handy, a normal pencil would do so long as your fabric isn’t black..
- Compass, or a means of drawing an accurate(ish) circle
- Optional: 20mm (or close) hole punch. You need a means of cutting tidy holes in the fabric for the velcro straps. I used a 20mm leatherworkers punch. You could happily use a sharp knife, or use a gas flame to heat a piece of copper, or similar tube (or pipe fitting) leftover from a plumbing project. I’ve used this approach in the past with great success; just try not to breathe the fumes.
1. Main body panel
a. Cut the wear patch to size. I radiused the corners by cutting around the lid of a small pot of lip balm. It just looks a bit tidier but does require a little more care sewing on. Mark the hole centers on a line 1″ (25mm) from one edge of the patch. They’re offset like this because the contact with the saddle is greater forward of the bag loops. For my C17 Cambium the hole centers are 4 1/2″ (114mm) apart. If yours are different as noted earlier then mark appropriately.
b. Cut the holes in the wear patch using your chosen method, whether knife, punch, sharpened tube etc, and align it on the main body panel such that the holes are centered and the edge to which the holes are closest is roughly 3″ (75mm) from the top edge of the panel. I used a little double sided sticky tape to hold it in place while sewing it carefully around the edge. Once sewn cut matching holes through the body panel.
c. Having sewn the wear patch in place, sew the webbing loop in place on the panel centerline such that the middle of the webbing is roughly 4″ (100mm) from the hole centers, or whatever distance you need to suit your saddle setup. The webbing loop should be long enough to allow plenty of leeway when attaching to the seatpost with a velcro wrap. When sewing webbing I tuck the ends under about 1/4″ (6mm) and, because my machine doesn’t do a true bar-tack, use the button-hole stitch setting to approximate a bar-tack to hold it in place. It works well.
d. Prep the zipper by cutting to 10″ length, or whatever your intended finished bag width is, then take one of two pieces of 1.5″ x 2.5″ cordura to make the zipper ends. Fold it about 1/2″ (12mm) in from one end and sew it over the ends of the zipper, on the outside, overlapping by about 1/2″ (12mm) from the end, and with the fold pointing back towards the end of the zip. These ends make it easier to sew the seam with the sides of the bag, and can be extended if required if using a piece of zipper a little shorter than the finished width of the bag; handy if using up scrap or recycled zipper.
As an aside, if you’re using waterproof zipper then I find the coated fabric can be quite ‘sticky’ for the needle and thread so you might find that you need to increase the thread tension setting on your machine a little. I frequently do little test pieces when working with a new fabric to make sure my setings are OK before embarking on a ‘production’ piece.
Repeat for the other end.
e. Sew the the zipper to the bottom of main body panel first, so the edge farthest from the mounting holes. Align the zipper with the outsde face of the fabric facing the outside of the zip and the teeth facing away from the edge. Sew along, then fold the fabric back along itself and run another line of stitching to secure the fold flush with the zipper. That stops a ‘shelf’ forming that could collect mud and water.
f. Now align the top edge of the body panel with the top edge of the zipper, outer faces in as before, and stitch.
Once the edges are joined such that the body panel forms a tube I haven’t figured out a way, on my machine, to do a second stitch all the way along the fold on the upper side. I’m probably being dim and should have perhaps just secured a zipper garage at one end first. However I don’t think it matters. I just ran a stitch in a little way along the top of the zipper garage.
2. The Sides
The reason the sides aren’t cut out earlier is that we want the diameter of the side pieces to match what we’ve actually made for the bag body, including the zipper and so on rather than what we thought we would make. This is also what you would do if making, for example, a round stuff sac for a cooking pot, or any other round cross section bag.
a. To calculate the radius for the side pieces flatten the body tube and measure across to get the half-circumference. The radius will of course be the circumference / (2 x Π). Using 3 or 3.1 for Π is plenty good enough, we’re not building aeroplanes. In this case half the circumference is near enough 8 1/2″ (635mm) so the radius of the sides of the completed bag will be near enough 2 3/4″ (70mm). We need to add a 1/2″ (12mm) seam allowance however so the radius of the side pieces to cut needs to be 3 1/4″ (83mm).
b. Sew the side pieces in place with the body tube inside out. Place one of the circles of material inside the tube aligned with the edge of the body, per the picture below, and start sewing 1/2″ (12mm) in from the edge (your seam allowance).
b. To sew all the way around you have to keep feeding the body through straight, effectively rolling the tube, and pulling the circle of fabric around to meet the edge of the body. Imagine a wheel rolling on a flat surface, albeit on its side, where the wheel is the side piece and the surface is the straight edge of the body. When doing this with a stiff fabric like cordura, and especially in a confined space, I find it easier to use a small pair of needle-nose pliers to pull the disc of fabric into alignment as I work my way carefully, and slowly, around the whole radius. Be sure to keep your seam allowance in mind, if you stray too far you’ll end up with a pucker somewhere. I got cocky and went too fast the first time and had to unpick the seam, you can see the stitch holes in the picture below… You will find that it’s not desperately critical however and a small pucker can be made to almost disappear when turning the bag right way out.
c. Repeat for the other side piece, turn right-side out and hey-presto.. a bag!
3. Mounting Bits
a. Cut your support dowel whether PVC pipe, bamboo, or whatever to length and remove any burrs from the ends that may othrwise wear through the fabric over time.
b. Now cut the support stiffener to shape from the piece of polypropylene, or whatever you’re using, and cut holes to match the holes in the bag body.
c. To assemble the bag on my Cambium I put a velcro strip through each bag loop, feed the ends down through the holes into the bag, then through the support stiffener, and finally around the support dowel and fasten. The support stiffener sits between the inner face of the bag and the support dowel.
All of this cinches up really nice and tight against the bottom of the Cambium so I’ve not needed to fix the support stiffener in place. If your saddle design means the bag can move about or needs to hang lower and looser you could run a couple of stitches through to hold it in place, or perhaps better yet run a couple of small self tapping screws (with washers) through the top of the bag into the support stiffener and the support dowel, with the heads positioned out of sight under the saddle. This is what Carradice do with their Zip Roll.
So there you have it. Very simple and quite practical with a very slightly retro bent despite the modern materials. Placed as it is in the photos, cinched tight against the bottom of the saddle, it does touch the back of my legs when I’m seated far back in the saddle while climbing for example, but it is a very light touch no different to the Carradice it replaced so doesn’t bothr me at all. It carries my daily riding around bits and bobs with ease and could be scaled up or down as desired. Modify as you see fit of course – add a loop for a rear light, or some extra webbing attachment points for strapping on a rainjacket if carrying a bit more stuff inside. You don’t of course have to make it out of cordura; denim or canvas if you live somewhere dry, or scavenged tarpaulin material would all work well. I quite fancy making one out of striped deck chair canvas one of these days.
The design doesn’t pretend to be waterproof. It’s reasonably shower resistant but if worried about water ingress, and especially if using a non-waterproof zip, then it would be a simple matter to sew a small flap over the zip. I’m not too bothered, I’m of the opinion that anything that has an imperative to be kept dry in there at all times, like a phone, should really be in its own waterproof wrapper anyway.