BMW motorcycle with sidecar (multiple)

BMW bike sidecar (Detroit 2010) 4700

I photographed this trio of BMW motorcycles with sidecars at Willows Run Airport 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.

BMW motorcycles with sidecar; Detroit 2010