The below photos (Copyright) are courtesy of Yesterdays.nl - thanks a lot
 https://www.yesterdays.nl/product-category/archive/motorcycles-archive/ 

The Big 3. For a time, they were the last men standing in the American motorcycle industry: Harley-Davidson, Indian, and Excelsior-Henderson. They fought hard on the dirt tracks, race tracks, hill climbs, and sales floors, and in their 1920s heyday, the competition between the Big 3 made for the most exciting racing anyone had ever seen, between the fastest and most advanced racing bikes in the world. Sales floor competition made each company improve their products dramatically, and by the late 1920s it was Indian and Excelsior-Henderson who dominated the 45cu” (750cc) market with the Scout and Super X models. Their big models (the Indian Chief and 4, and the Henderson 4) were admired the world over, and were in many ways the most attractive and technically interesting motorcycles built in the USA. But larger forces were at work in the marketplace, far beyond any company’s control, that determined the fate of the Big 3.