The first time I saw the sidecars was in my early childhood in ‘61 or ‘62 ... in Spa-Francorchamps. ... BTW, many scenes in your video are from that race track.
I remember the top team of the first half of the 60‘s very well … Max Deubel & Emil Hörner with their BMW (the ones at 0:36 in your video). They became world champions 4 years in a row. I was at Max Deubel‘s home once in the mid 60‘s with my father and my brother.
At 0:50 in your video is the Swiss/British team Fritz Scheidegger & John Robinson with their BMW. I always wondered how Fritz Scheidegger could do that … he wore very thick glasses, he must have been half blind.
I was impressed by Helmut Fath who built his own sidecar including its 500cc inline 4-cylinder engine (!) which he called “URS“. He won together with Wolfgang Kalauch the world championship with that sidecar in 1968.
I also liked the top team of the first half of the 70‘s very much … Klaus Enders & Ralf Engelhardt on BMW. They were world champions 6 times.
My favorite sidecars, however, were the ones with the 500cc 4-cylinder two-stroke engines up from the mid 70‘s. ...