One of the biggest issues I have with my bike is the seating position. I am of a somewhat long legged variety and the super short seat height puts me in a very uncomfortable position. I have a Mustang vintage solo on it now and while it is an improvement over stock, about an inch taller, it still has me pretty cramped that makes longer rides painful. My plan is too build up the seat height enough so that my knees are not higher than my hips.
When I built my rack I built it for my solo seat and it takes up the space that the passenger section of the seat would go on a standard seat. I could build a new one but I'd rather keep the solo seat.
What I'm shooting for is a similar look to this.
Basically a solo seat that is taller to fit my legs better.
So, I started with the stock seat and stripping it down to the seat pan. I stored the factory foam and cover so that I may return it to stock one day. Very simple job, just pull the staples out and everything just comes off.
That leaves me with the bare pan to build from.
I went to the local Wrench a Part and procured a nice rear seat cushion for $8.00. Excellent Idea I thought. I picked a seat that didn't have the metal frame molded into it. I believe mine came out of a Chrysler Sebring sedan. 
The problem is it's pretty soft. Too soft to be useful? Maybe, time will tell. It is certainly too soft to use from the pan up.
First job was to build up the pan into a flat surface. I used a foam mat that I had. Unfortunately it's a little thin so it was going to take a lot of layers to get it flat. I grabbed my can of 3M super 90 some scissors and got to work. 
After three layers. 
After cutting and gluing several more layers I started adding strategic pieces to the low spots as well as grinding down some of the high spots.
After many hours of cutting and gluing I had a relatively flat seat, and I was out of glue.
Up next is some trimming, get some more glue, some shaping and some test riding.
Some more progress this morning.
Not really knowing what I'm doing or the correct way to approach it. I plan to get the shape close first, then work on getting the comfort right.
I glued on an oversized piece of seat foam and then put it on the bike and marked where I wanted to cut it. 
I'm working on fine tuning the shape. The height feels right. It's looks like I was pretty close with my crude rendering.
Good news, I love the height. It's perfect.
Bad news, It's like riding on a 2x4. The car seat is way too soft and the black mat is way too hard. I attempted to laminate layers to create a compromise but it's evident that the seat foam is just way too soft to give any support. I don't mind the flatness of it. I like being able to sit all the way up against the tank, or all the way back. I just have to come up with something that will alleviate the pressure on my sit bones.
More pictures.
I took out a couple layers of the hard mat.
And laminated it, foam/mat/foam.
Back together for a test ride. Again, it proved to be too much pressure on my sit bones.
I put another layer of mat on top which was a noticeable improvement but still the foam does not give enough support allowing my sit bones to contact the mat underneath hard.
That's where I left it for today. More work is needed.
Nice! The shape looks good- back to the junkyard for more foam? Or maybe a thrift shop for yoga mats/kneeling pad/whatever those things you're supposed to put on bleachers are called? Major bonus points if your new cover material is a jacket from said thrift shop 
In reply to ¯_(ツ)_/¯:
If I ever get the padding right I'm probably going to drop it of at an upholsterers to get covered. I would love to sew up a cover for it but I don't have a sewing machine and I don't have the budget for one.
Different approach. I tried going my own way and that didn't work. So I backed up and went with the more common rebond padding. I also read many comments that the shape is more important than the padding for comfort. To that end I made some modification to the shape of the mat layers and then built up the padding above that. If I wasn't so impatient I would have hit up a carpet store or two to get some carpet padding remnants. Instead I went to Home Depot and bought a roll of padding intended for an area rug. It's only 10mm thick, I would have liked to have found thicker but that's all that was available. I used the rest of my second can of adhesive gluing 6 layers of the rebond on.
After roughly shaping it I went for a test ride. It's good. I don't know what I would do to make it any better. No pressure points anywhere. I'm going to ride it some more before I think about making any changes.
You can see how much more pitch is in it, as well as the higher nose.
It's a little hard to see but there is much more cradle to the seat area
So it looks like just fine tuning and then smoothing everything out so it's ready to accept a cover.
Nick (picaso) Comstock wrote:
In reply to ¯\_(ツ)_/¯:
If I ever get the padding right I'm probably going to drop it of at an upholsterers to get covered. I would love to sew up a cover for it but I don't have a sewing machine and I don't have the budget for one.
A used sewing machine would probably be cheaper than having an upholsterer do it.
I have one like this and it should have no trouble with a seat cover.
http://austin.craigslist.org/atq/5666875336.html
Cool, you,re making it look like an original Sportster.
In reply to wheelsmithy:
I think it'll look a little goofy when it's all done. I don't really care too much about how it looks though, it's all about how it feels. It was either fix the ergos or move on to another bike.
But it certainly opens my hip angle up. It's a so much more comfortable position. I have no idea who got it in there head the these things had to have the lowest seat height in history, but I'd like to kick them in the balls. I can still flat foot no problem.
EvanB wrote:
Nick (picaso) Comstock wrote:
In reply to ¯\_(ツ)_/¯:
If I ever get the padding right I'm probably going to drop it of at an upholsterers to get covered. I would love to sew up a cover for it but I don't have a sewing machine and I don't have the budget for one.
A used sewing machine would probably be cheaper than having an upholsterer do it.
I have one like this and it should have no trouble with a seat cover.
http://austin.craigslist.org/atq/5666875336.html
After the quote from the upholsterer I believe you are right. Or more accurately could do it myself for the same money and have a sewing machine left over for any other little projects that may come up.
The one linked to is gone.
Any advice on buying used sewing machines?
Could a treadle machine work or should I be looking for an electric?
Got the final shape where I wanted it. Got it smoothed a little and put the layer of smoothing foam on it. Now I just need to figure out what I'm going to do about upholstering it.
Is it just me, or the pic, or does that look a little lopsided??
In reply to jfryjfry:
It sure looks that way in the pictures. The curve is slightly sharper on the right side and more gradual on the left. I'm not too concerned about it. I can make minor adjustments in it by pulling the cover tighter.
You know, Pablo Picasso was never called an a*hole.
In reply to Nick (picaso) Comstock: Obscure reference to a Modern Lovers song. A few bloody Marys may or may not have been a factor in my thinking someone might gt my nerdy joke.
Seat looks good!
