Came upon this and thought it as interesting... Basically, in addition to various vintage classes, the Retrocross series runs a class referred to as 2x4.
The requirements are: Four stroke, air cooled and no greater than 230cc. Aside from those considerations it seems anything goes!
The humble XR200 seems to be the most popular bike, but I guess it would be open to DR200, XL/XR185, XL200, CRF230 and TTR230.
From mild (standard XR200 with headlight and tool bag still attached) to wild (see below) the emphasis is on fun racing.
[Pics from Thumper Talk]From what I understand the trophies for this class are made by the actual participants, so no two are ever the same!
Tex
