bdkw,
I think these have an electric push button gearshift, meaning the CVT changes ratio when you click a button on the left handlebar. Thats maybe what the 2nd motor is for.
EDIT:
This pic shows how the electric motor controls the CVT
From this article:
http://www.cmgonline.com/articles/CMG02 ... SECVT.html
EDIT II:
Even better, heres an animiation showing how it all works:
http://www.pirmil.info/scoot/ssiburg/65 ... demo.shtml