This is how the cover of my bike looked like after years. The central padding weld has weaken and eventually broke letting water soaking the internal foam and making the seat unusable during rainy days unless covering it with some
Step 1: Before You Start...
...make visual inspection of all the parts making your seat and how they are assembled togheter.
In this case we have double stitching like the one in the drawing which I have tried to reproduce.
Step 2: Take Reference Points
Since many parts are sewn following a curved path, it is important to mark references lines before separing the pieces. Such lines will be drawn later on carboard and used as a guide during sewing process.
Step 3: Divide Et Impera
After marking a significant number of reference lines, it is possible to unstitch/separate the parts aside.
Step 4: A Flatten Edge Makes Life Better
With the help of an iron set to wool temperature, flatten the edges of the parts, so that later it will be easier to report
all the shapes on cardboard. It would be possible to transfer the shapes directly on the replacement tissue, but i wanted to store the templates for later uses.
Step 5: Trace It !
Now it's time to trace all the flattened parts on cardboard wich can be then cut with scissors or a cutter. Dont forget to draw also the reference signs!
Step 6: Get the New Parts!
Now, with the help of cardboard templates, draw outlines of all the parts on the new material. Also don't forget to draw references marks.
Step 7: Put All Togheter
With the help of a manual needle and cotton thread, join the parts, trying to match the reference marks. Due to the curveous nature of the sewing line, the overall result won't be flat neither it has to be. That's why is so important to mark the reference lines before separing the parts. Also it is helpful to add a sewing reference line at a distance from the edge as can be seen in the last picture. (The first three pict were from a failed attempt)
Step 8: This Was the Intended Stitch
I've tried it on a straight piece of material using also a guide on my machine to help keeping the stitch consistently aligned. That worked for straight stitches. For curved lines it was not so precise.
Step 9: Glue Time
After some time, you eventually will come to an end, ans its time to put the cover back on the seat's foam.
I do prefer to do it in a sunny day. I expose the new vinyl fabric cover to the direct sunlight so it soften a bit and I can stretch it under the edges of the seat. Before I do that though, I cover the edges with contact glue which I let dry. Then, when the fabric has soften a bit I stretch it and I fold its glued edges to the glued edges of the seat.
To complete the assembly, I use metal stitches to secure the fabric permanently.
Step 10: That's All Folk
And here is the final outcome. As said before, sewing along curved path with my machine is problematic, hence some imprecision in some stitching.... but overall I'm satisfied.
Hope you'll like it