I'm not sure where to place this, but it is construction.. sorta...
The original seat on my ST1100 was in good condition foam-wise, but the cover had some small splits in it and had gone hard.
I wanted to buy another standard seat and then have a go at reshaping mine, but standard seats don't come up for sale that often and then they seem to fetch a good price.
I managed to get hold of a Sergeants seat, and replaced the standard seat with it. It had a better shape to it, and it let me sit slightly lower but it was still too hard and didn't shape to the bum, so I still got aches on longer trips.
Now I am out of work I have more time but less money, so I thought it was time to have a go at reshaping the original seat.
I found the website that gives great information on how to rebuild your motorbike seat. I asked around trying to get decent foam, etc.. but not much luck.
The last auto upholsterer that I went to said that he had modified a few motorbike seats and his approach was to buy exercise mats from BIG W.. cut them to pieces and layer build up areas that need building up on the seat.
Tools needed: angle grinder with a worn sanding disc (I had a worn flap disc), and cheap electric bread knife.
The standard seat tilts the rider forward and this, for me, put too much pressure on my wrists. I fitted the 3.5" handlebar risers.. and that was good, but that caused the seat to put pressure on the back of my bum. So, I lightly ground away at the foam at the rear of the riders section of the seat and took it down ~40mm. Still plenty of foam support left. I ground some of the edge of each side of the seat where my legs hung over.. all the time feeling with my hands and sit-testing the seat. I eventually got it to a shape that felt good, so I went for a local but extended ride. Came home.. made some adjustments, etc until I was happy with it.
Then, looking at the website and comparing to the Sergeants seat I had to increase the foam height in front of me.. so I added about 4 layers of the Dunlop exercise mat and ground and cut it to shape. Went for a ride and realised that I needed more ball-room!!! So back home and ground some more.. I am very happy with the improvement so far.
BTW.. and experience rider trainer showed me the cover on his modern bikes seat and it was more flexible than mine and also a dotted texture to it, where mine was hard, smooth and slippery. So once I have finished modding the foam I will look out for some decent cover material for it.
More later....