East versus West
The excellent photo with the OBA BMW
R80G/S story of the huge guy belting his big ISDT Bee Emm through a Euro forest is exactly right. It took a strong rider to pilot those flat twins in offroad as they were so much heavier than their competition.
But we’ve forgotten how in the 1960s that meant another very serious competition for the Germans east versus west with both sides of the then “cold war” out to prove superiority. I clearly recall the determination of the then West German team. Although a few riders had 125 Zundapps for the small class, the prestigeconscious riders had BMWs to compete against the more suitable East German MZs.
While the Beemer in your photo boasted prototype telescopic forks (and strange crash bars), many of the flat twins had the then production leading link forks that were heavy. With strong riders those ISDT BMWs did well, all things considered.
Undeniably the real bike stars of that era of annual ISDT international competition were the range of East German MZ two strokes. For political reasons they had a government budget on bike development and rider training with proper back-up