How to Make a Custom Template for a Bike Seat Cover

Making a bike seat cover was never really on my radar until my bike seat started to crack from sitting outside all year. Every time it rained, the foam inside soaked up water like a sponge. I can’t tell you how many trousers I’ve ruined thanks to that dreaded wet patch — so embarrassing!

That’s when I knew I had to sort it out and make a custom bike seat cover. It turned out to be such a satisfying project. Now, the seat is protected from rain and sun, and because I drafted the pattern myself, it fits like a glove with no slipping or bunching. If your bike seat has seen better days, this easy fix makes a big difference!

In this blog post, I’ll show you how to create a custom template for your bike seat cover. I’ll walk you through the entire process so you can confidently make a cover that looks great and stays put. Whether you’re new to pattern drafting or want a practical sewing project, this is a great one to try! In the next post, we will sew it together! CLICK HERE to check it out!

Why Make Your Own Bike Seat Cover Template?

Bike seats come in all sorts of shapes and sizes, which is why finding a cover that fits well can feel impossible. Unless you find one specifically designed for your bike seat (good luck with that), most store-bought covers are either too small or too big. Some of them honestly look like nappies, and let’s be real; no one wants that.

If you’ve ever tried using a cover that’s not the right size, you’ll know the struggle. It bunches up, shifts around while you’re cycling, or worse, slips right off mid-ride. Super annoying, right? That’s exactly why making your own custom template is the way to go. When you draft your own pattern, you’re making sure the cover fits your bike seat perfectly so it stays put and actually does its job.

Plus, a well-fitted cover feels better to sit on. No more awkward padding in the wrong places or slippery fabric making you feel like you’re sliding off the seat, and if you’re using waterproof fabric, it’ll protect your seat from rain. Taking some time to create a proper template means you’ll end up with a cover that looks good, feels comfortable, and stays exactly where it should be. Trust me, it’s worth it, and it only takes a few minutes!

I could have easily bought a new bike seat, but since my bike sits outside, there is a chance the new seat will also crack. Plus, I’m not really into spending money on things that aren’t super essential.

I prefer to get creative and make things that I actually use. That’s why creating a waterproof cover for my bike seat was such a fun project. It’s a simple solution that’s both practical and personal. I’m even thinking of making a few more in different colours, maybe one for each season or a festive one for the holidays. It’s a simple way to personalise my bike and make it more customisable.

Since my main goal was to create a waterproof cover, I kept it minimal. There’s no padding or lining, just a straightforward, no-fuss cover that does what it needs to: protect the seat from the elements.

Step-by-Step Guide to Creating a Bike Seat Cover Template

Once you’ve got all your supplies ready, it’s time to start drafting your bike seat cover template. This part is pretty straightforward, but taking your time and being precise will make a big difference in how well the cover fits. The goal here is to create a template that follows the exact shape of your bike seat so it sits nicely without shifting or bunching while you ride. Let’s walk through the steps to get it just right.

Step 1: Trace the Shape of Your Bike Seat

Start by placing your bike seat face down on a large piece of paper. Hold it firmly in place to stop it from shifting as you work.

Next, take a pencil or pen and carefully trace around the edge of the seat. Keep your pencil at the same angle all the way around — this helps you get an accurate shape and ensures your template will fit well.

➡️ Here’s a handy tip: If you keep your pencil upright at a right angle to the paper, your finished cover will have a slightly looser fit. If you’d prefer a snugger fit, hold your pencil at a slight angle towards the seat as you trace. This brings your outline closer to the edge of the seat, creating a tighter template.

Once you’ve traced the entire outline, carefully lift the seat away from the paper. You should now have a clear shape to work with for the next step.

And don’t worry if the outline isn’t perfect or the line looks a bit wobbly — we’ll tidy it up later, so it doesn’t need to be flawless at this stage!

Step 2: Find and Mark the Midpoints

You’ll need to find and mark a couple of midpoints to ensure your pattern is symmetrical. This will help keep everything balanced when you sew the cover later on.

My favourite way to do this is with a tape measure. Start by placing the tape measure on top of your draft, lining up the beginning with one side edge. It doesn’t matter exactly where you put it. Just pick a spot that gives you a straight path across the template.

Next, keep the tape measure flat and fold it over so that the beginning meets the opposite side of the draft. The midpoint will be where the tape is folded. Flatten the fold to get an accurate spot, then mark that point on your paper.

You’ll want to repeat this step again in another spot to ensure everything is lined up correctly.

Then, take a ruler and connect the two points to draw a clear centre line.

Step 3: Mark the End Points

Since we will work with only half of the template, you’ll want to square off the ends to keep the shape neat.

Take a ruler and draw a short line at each end of the centre line. These lines should be at a 90-degree angle to the centre line. This helps prevent the cover from having weird, pointy ends once sewn. Keeping these ends squared off will give the finished cover a cleaner look.

Step 4: Smooth Out Uneven Lines

Now, it’s time to clean up your template. Pick the better half of your traced outline — the side that looks more even and smooth. If you notice any lumps or uneven lines along the edges, smooth them out with your pencil.

Take your ruler and gently adjust the curves or straight sections to make sure everything flows nicely. The goal is to have a clean, smooth shape that will fit your bike seat perfectly.

Step 5: Add Seam Allowance

Now that your template looks nice and smooth, it’s time to add the seam allowance. I like to add a 1 cm (about 3/8″) seam allowance around the edges to give myself enough space to sew the pieces together without worrying about cutting too close to the edge.

Since you’re only working with half of the pattern, you only need to add the seam allowance to that half. If you’d like, you can erase the other half of the template, but since I used a marker, I ignore it and focus on the half that’s relevant.

Just make sure the seam allowance is consistent all the way around.

Step 6: Fold the Paper and Cut Out Your Pattern

Once you’ve added the seam allowance, it’s time to cut out your pattern.

Start by folding the paper along the centre line. This fold will give you a mirror image of the shape, so you only need to cut one side.

Once it’s folded, use your scissors to carefully cut along the outer edge of the template, following the seam allowance you added earlier.

You can now open the fold and see your complete, symmetrical template!

Step 7: Measure the Length of the Seam

Now we need to figure out how long the gusset will be — that’s the piece that wraps around your bike seat. To do this, we’ll measure the length of the seam. But since we’re only working with half of the template, we’ll measure just one side.

Take a tape measure and place the beginning at the midpoint of your pattern. Make sure the tape is at a 90-degree angle to the paper, not flat against it. Keeping it at an angle will give you a much more accurate measurement.

Now, carefully “walk the seam” by slowly moving the tape along the curve, following the outline. Be sure to measure along the stitching line (not the edge where you added the seam allowance). Keep the tape taut and precise as you go, all the way to the other midpoint.

For me, the measurement came out to 41 cm (16 1/8″), which is half the length of my gusset.

Step 8: Determine the Width of the Gusset

Now that we know the length of the gusset, let’s figure out the width. Take a tape measure or a ruler and measure your bike seat at its widest point. This is usually somewhere near the back, but it can vary depending on the seat shape. For me, the widest part measures 8 cm (3 1/8″).

To ensure the cover stays securely in place, I suggest adding a bit of extra height so the gusset wraps around the seat better. I decided to add about 2 cm (3/4″) for a snug fit.
Write down your measurements so you don’t forget them.

Step 9: Create the Gusset Pattern

Now that we have the measurements, it’s time to draft the gusset pattern. Take the width and length of your gusset and draw a rectangle in that size on a piece of paper. Since we’re only working with half of the pattern, you can add a CUT ON FOLD marking along one of the shorter edges.

I like to add a couple of arrows pointing toward the fold edge as a reminder. When cutting out your fabric, you’ll need to fold the fabric and place this edge of the pattern along the fold. This way, when you cut and unfold it, you’ll have the whole gusset piece in one continuous strip.

Next, add your regular seam allowance along the top and the other short side. You should use the same seam allowance that you added to the main panel. In my example, that’s 1 cm (3/8″).

The bottom edge is where we’ll create a tunnel for the elastic or cord, so you’ll need to decide if you want to fold the edge once or twice. You’ll also need to consider the size of your elastic or cord. In this example, I’m folding the edge twice by 1.5 cm (5/8″), so I need to add a 3 cm (1 1/4″) seam allowance along the bottom edge. My elastic is 7 mm (5/16″) wide, which gives me plenty of space to feed it through the tunnel.

Remember, when you sew the tunnel, you’ll need to stitch close to the folded edge to keep it in place. This will slightly reduce the size of the tunnel, so it’s best to measure your elastic or cord and add at least 5 mm (1/4″) of ease to ensure it slides through easily.

Now that your pattern is complete, go ahead and cut it out.

Step 10: Annotate Your Pattern

Before you set your pattern aside, don’t forget to label your pieces so you know exactly what they are in the future. It’s easy to forget details if you return to the project later!

At the very least, I recommend writing:

• Project name – e.g. Bike Seat Cover
• Pattern piece name – Main Panel or Gusset
• Cutting instructions – e.g. Cut 1 or Cut 1 on fold from waterproof fabric

You can also add seam allowance details, the date, or any notes that might help when cutting and sewing, like the size of the elastic. A few quick annotations now will save you a lot of guesswork later!

Check Out the Video Tutorial for More Tips

If you’d like to see the entire process of creating the pattern, I’ve got a video tutorial on YouTube where I walk you through every step.

I share some extra tips along the way so you can better understand how to make your template fit perfectly.

Feel free to check it out and let me know what you think! If you have any questions or are stuck, don’t hesitate to comment. I’m always happy to help out!

And that’s it! You created a bike seat cover template that will fit your bike perfectly. I hope this guide has helped you feel more confident in drafting your own patterns and that you’re excited to see how your cover turns out. It’s a satisfying project that solves a practical problem and lets you personalise your bike. If you have any questions or need help along the way, just leave a comment below!

I’d also love to see your creations. Feel free to share them in my Facebook group or tag me @allsewpetite on social media.

And remember, this is just the first step – stay tuned for the next post, where we’ll dive into sewing the cover.

Stay crafty, friend!