this is deffinetily not 1928. It is late 1929 or 1930. In 1928 there was still TIGER front fork and diffrent exhauast. This BS with the license build CASTLE fork was introduce in second half of 1929. The BS500 Standard was the best selled sport motorcycle for 1928 in Germany. Then in 1929 they goes a step back because of the IMPERIA 500H which was cheaper then Standard. Incredible motorcycle and you are right “Alfred’s expression says it all.”