British

Raynal 1921

Raynal-1921-4.jpg
Strangely, although it was 1931 before V-belts were used on small industrial machines (in the U.S.A.) they had been available for motorcycle use from the early years of the 20th century. The belt fitted in this case is a modern "Brammer" link type.
(Apologies - credit for image and text has gone missing)