This is a very rough description of a fiberglass seat pan that I have mounted on my bike.
The system consist of three parts, a bottom seat pan, a top seat pan, and a seat
The short view is that it acts as an inverted fiberglass bow.
The two halves of the seat pan base are connected at both the front and back, with the back being thinner. As weight and pressure increases on the top plate it forces the back end to move forward making the distance shorter. This causes the top plate to draw the bottom plate inward at the back. As pressure returns to normal, the fiberglass “spring” returns to the original shape with the top plate rising back up and the rear end straightening back out.
The seat itself has a bit of flex and is mounted to the seat pan at three points with rubber washers.
I have only had it on for a few days and I feel sure it will need some serious tweaking, but the concept seems to work. The overall give is probably less than an inch.
I got expensive shocks on the bike, but a rigid seat and a quick pothole equals an instant migraine.
Once I get the bugs worked out I will finish the glass out and cover the seat with foam and leather.
My first discovery was that my Butt is a lot bigger than I thought it was…I got to add some inches to my handmade seat!
I will update you as I learn more."
"Springs! We don't need no stinking Springs!!!