Hello Walt, to answer your question about the carbon fiber version…….this version is made with carbon fiber and fiberglass. We are reinforcing all 4 mounting areas and bottom of seat with carbon fiber. We are also utilizing the Ribtect “X” pattern in the carbon version…….using uni directional carbon fiber strips. More information on the “X” pattern can be found here: http://www.ribtect.com/RibtectSeat_Original.html The carbon version will ultimately be stronger…….yet still flexible. The all fiberglass version will have a similar flex and will have the same shape as the carbon version as they all come off the same moulds.
Like Patrick mentioned, you can fine tune the fit of the upper portion of the seat by adjusting the welded struts. The seat does not have a rolled lip which allows you to squeeze the top of the seat in or out if necessary to get the fit “just right”.