Motorcycle manufacturers need to design concept or prototype motorcycles so that they can test out the design's reaction from the riding public, or to make sure that all their ideas work in practice.
So often at motorcycle exhibitions, you can see far out motorcycles, often no way resembling what real life has in stock. Many of them are so sci-fi that even a Hollywood producer wouldn't use them, and then some are so "bland" that you'd expect to see them at your local motorcycle dealer.
Here are 44 concept motorcycles from the big four Japanese motorcycle manufacturers. Only Kawasaki has very few concept motorcycles that were innovative enough to show.
Not all concepts are "hard", ie, they're drawings, and some are not from the manufacturer, but from independent designers.