Following the series of Concept motorcycles from the big four of Japan (link), Part 1 (link) and 2 (link) of the European motorcycle manufacturers, now we'll have a look at the North American manufacturers, plus a few others I could not place.
The concept motorcycle can be anything, from a design study to a riding prototype. The concepts are there to see if a) it can be done, and b) if the public likes it.
So here are 13 North American concept motorcycles, and 18 other concept motorcycles I could not place.
Okay, the last one wasn't a real concept, but it's cool...