The leathercloth on the was well and truly past it’s best, so I thought it would be nice to continue the colour scheme through the seat. I’ve been through three iterations of designing a custom seat for my ST1100 (I’ve got short legs and a high wide bike becomes an issue) so working in Vinyl is no problem. The first thing you need is the right sewing machine. You can just about get away with a large domestic one, but the little 12V one I had definitely couldn’t cope. A bit of research revealed that there are two types of machine that will do a good job on it. You can get a second hand heavy duty commercial machine for about £1500 to £2000 or any hand cranked Singer built between about 1890 and 1940. I got mine ( a 1930 Model 28 Singer) from the inevitable source for tenner. It ran straight from the box, though it took me a bit of time to figure out the right tensioning for everything. New needles for £5 are a wise investment. Using a heavy duty thread is a good idea if you can find it, but it doesn’t need to be the fancy twine that you’d use for leather. My current Pan seat was stitched with Tesco’s heavy duty thread, has done about thirty thousand miles and none of the stitching has given way.
Whilst the thread isn’t super critical, the structure of the seam most certainly is. It must be overstitched, like the outside leg seam on your jeans. That means that you stitch a normal seam, turn one side over and then stitch through the whole lot again (the picture makes it clear) that way the pull on the thread (and the holes) is very much in shear and doesn’t pull the seam apart.
The exception in this case is where I put the black stripes on, but they just sit on top of a single piece of white vinyl, so there’s no structural element to the seams. Incidentally, I can’t feel the stripes, even on the odd occasion when I’ve nipped out in a pair of thin work trousers. The other trick for the seat was to make the pad on the bum stop bit hinged, which gives me access to the hump, where I keep a disc lock and a bit of towel. The flap is just held up with Velcro. The original foam was rather nasty and fell apart when I took the vinyl off, so I replaced that with a Yoga mat from a charity shop (£3). It’s quite firm but, because of the way the riding position works out the riders weight is spread along a fair bit of thigh and I’ve never had any numb bum problems on runs of an hour or less.
The off white vinyl had faired quite well through the winter and still scrubs up clean with a bit if effort, which it very seldom gets.