While reading this thread last night I had an idea. How about custom adapter plate for the KH bicycle style seatpost that allows you to adjust the angle of the seat without the need for rails. Rails are undesirable for a trials uni because the create a finger trap. But even on a trials uni it is nice to have adjustability for the seat angle.
The standard welded unicycle style seatposts are also not holding up to hard use. They break at the weld. The aluminum versions are cracking at the seat plate mount.
A custom adapter plate for the KH seatpost would solve those problems. Make the adapter out of steel so it would be strong and wouldn’t suffer the cracking problem that the aluminum plates have. The KH seatpost is strong so it should avoid the bending problems. You get the best of both worlds and keep the weight reasonable at the same time. No more rail, adjustable angle, a strong seatpost, and reasonable in weight.
Then I took a look at Unicycle.com UK and saw this: Seat Post - Suspension Adaptation. Same general idea. So the idea isn’t new.
The new and improved KH adapter concept:
