Although my bike came with a Sargent I found that it had the same problem as the stock seat, they are both slanted forward, so that I'm constantly sliding into the tank, on to the narrow part of the seat, and crushing gahonees (s?). So, figured the stock seat would be easier to mod than the Sargent:
Disassemble seat and take the vinyl off the front portion. Then take a bread knife and cut the slope off the back so that it's flat; you're taking off about an inch at the rear:
You then get your self some 1" rebonded foam and some adhesive.
With the foam out of the seat pan you spray the seat and the rebonded foam. While they're both getting tacky, cover up the bike with some Saran wrap.
Put the seat foam on the seat pan (over the plastic), lay the rebond on top and sit on it to get a good bond.
Take it off, do the rough trim around, and it's starting to look like a seat.
This is the time to contour and trim if you want, but for me it's simple. I want it flat (achieved) and I want it wider everywhere (wrapping an extra inch on each side takes care of that).
You then get some nice stretchy vinyl and a staple gun... stretch, fold, more staples, more stretch, more fold... that is the hardest part of the job... assemble it all... and there we go:
Notice anything funny? Yeah, it looks like I stuffed it with cottage cheese... That's because the rebonded foam is not what I would call virgin. Plus the vinyl I used is very stretchy. So, every little joint or edge in the foam shows up.
The first time I did this, on a previous bike, I just used solid foam, so that's one way to eliminate the problem. Virgin rebonded foam would be another way to solve the problem, or just put some batting over the foam before stapling on the vinyl.
Anyway, for about $60 the difference is night and day. Where you put your butt is where it stays... no sliding... no crushing the boys...
Then to get my ergos completely where I wanted them I slapped on a Fly Racing "Mini" handlebar; about the same rise, but flatter with less pullback...
My shy helper turning the wrench:
And the finished product...
I'm in heaven...