Sofrider was the first commercially-available Cruzbike (aside from the conversion kit, which did not include a frame). As the availability of suitable Y-frame mountain bikes on which to install the kit got worse, the V2/K frame was introduced to give converters something to use the conversion kit with. As the name implies, it was a Version 2 Sofrider frame (Version 2/Kit), off the Sofrider assembly line, painted white instead of silver or blue. The Sofrider fork was not made available, which is why your bike has a conventional fork (which is installed backwards in the photos, by the way - fork rake should point to the rear to preserve the proper trail dimension for best steering). This was a time of very rapid product development for Cruzbike. Development of the Quest followed very rapidly behind the V2/K. Then Silvio 1.5, then Silvio 2.0, 2.1, and the Vendetta overlapped several of these. In effect, each series followed its own development path and timeline, so there is some overlap.