Gives me ideas.
I could chuck half the video with a goped clutch drum bearing with 12mm thread stub.
I like the clutch, better than what I did.
I wanted to try belt drive on mine, the 2-stroke smoked chains, but I got my etrike and chucked the FD.
The advantages are better torque with larger rollers.
Disadvantage? Added friction and load. Frankly when I did a direct drive with the same engine, it ran circles around my avatar bike.