The 1915 Rover counter-shaft drive.
The silent chain conveying the drive from the engine shaft to the gear box is shown on the left; the kick starter, shown in the second illustration, is combined with the gear box and is located on the other side of the machine. Of course both chain and kick starter are enclosed.
Source:
The Motor Cycle, November 26th 1914.
Rover Motorcycles 1914 Models