I think they made an error with the central location of the motor and chain drive. It would be better with a hub motor. It would be cool to have a dirt bike with hub motors and selectable 2-wheel drive. You could even use the motors as the brakes.
The reason they dont do that is because thats a lot of unsprung weight (bad for suspension action) and move weight to the ends of the bike (bad for handling) both things which are bad.