...and you're waiting for a reply, I can guess that there are several reasons:
- The Silvio was designed as a platform by which one could transfer parts from their traditional roadbike. This was the beauty of the design which is expressed in John Tolhurst's video that I watched way too many times on YouTube.
- The Vendetta followed suit with the concept of the "build your own" Silvio
- The Quest can be packaged as a full bike into a box that is roughly half the size of a typical bike box; this allows for more affordable shipping of a complete bike.
- The Quest was designed from the ground-up as a whole bike; this (almost) ready-to-ride design appeals to a lot of people in the market for a mid-price, all-rounder recumbent.
I may be wrong on some of these points, but it's just my two-cent's worth. I also have thought about things like that; why not a quest frameset? Or why not offer a true Sofrider frameset with the proper front triangle rather than requiring a V2/K + conversion kit. I can only assume that there are manufacturing costs involved that make sense to offer one and not the other. Frankly, I'd love to have several of each frame and configuration so that I could "play around" and come up with some really neat stuff!