Motorcycles with sidecar (multiple)

BMW bike sidecar (Detroit 2010) 4700

I photographed this pair of BMW motorcycles with sidecars at Willow Run near Detroit. One of the experts from the Hyperscale nation says the dark bike appears to be an R71, but is unsure on the sand-colored bikes, noting that if they have overhead valves they most likely would be R75s. I have not been able to identify the combo at Planes of Fame in Chino.

BMW motorcycles with sidecar; Detroit 2010

Motorcycle with sidecar; Chino PoF