Difference between a vx an sp/fx

what is the actuall diff bewteen these two? cos on the 2 strokes it appears u can mount another rear shock 2 the frame.
but i wana know more about the engine mounting, could you fit a 2stroke suspension linkage into a vx frame?
cheers in advance peeps

 

well bascially its as if the frames are all the saem apart front the engien mount area as even 50s have the 2nd shock mount, obviously its easy to make the frames all the same and change jsut the engien mount area rather than loads off different machines for just a shock moutn hopoe this helps

 

wel the sp dont have a linkage system, its just a rear shock.
the vx has twin rear shock with different mounts, but in theory you could change the mounts on the shock (ive done this for my sr).

TBH they do nice Bitubo twin sets for the vx's anyway!! lol

 

just wonderd, i need a 125 2stroke frame an was just takin a shot in the dark to see if it was possible cos 2stroke frames an that easy to come by anymore