Thanks for the comments everyone. I really built this first version as a “proof of concept”.
To provide a mounting base for the springs I got two right angle brackets and attached them to the frame where the rear air box bolt goes. This provided a horizontal mount two connect the base of the springs to.
The springs are 4” tapered springs from 2fastmoto. They are the third set of springs I tried, as the first two were either too big or too small. Plus I think they look sexy in black.
The seat itself is just a cheapy from China via eBay. I wanted to try a different style on some decent rides before I spent a couple of hundred bucks on a decent seat. You could definitely use any seat, the stock seat pan might just require some extra holes drilled in to attach bolts to connect to the top of the springs.
I’ve attached the front of the seat to the existing side mounts.
Overall I really love the look and feel. I’m thinking I’ll get a slightly larger seat with some decent leather and foam, maybe from La Rosa, to complete the look and keep my arse happy.
I’ll add some more photos. It is difficult to get decent photos of the mounts because everything is black.