I was scavenging in the archives of the old site and found this. I believe the bike is a Pannónia, a brand of motorcycle manufactured in Hungary. It’s hard to see the bike with all that sidecar and the girl, but it’s a good photo.
source: internet, unknown. Retrieved from the archives.
from left to right: Robert Grogg and Andreas Grabner (Switzerland), Sergey Shcherbinin and Boris Poganovsky (USSR).
Grogg/Grabner crew won the stage of the FIM Cup in sidecar motocross class. Shcherbinin/Poganovsky took 2nd place, riding Ural-900 motorcycle.
Photo by Chris Somers
source: Foto magazine MOTOR 1973, Andrey Spitsyn
A beautiful photo, with a very supportive crowd of onlookers, with a sidecar crew anticipating the race ahead. Wonderful.