Or Stevenson's cycle
http://lh3.ggpht.com/_kquDjkzHXwQ/SpvwE5B8JEI/AAAAAAAAAYo/FcBRhaJv26c/MF8O1886.JPG?imgmax=800Yeah, it's been done. A few times or more.
In Stevenson's case, for looks.
In the case of the Vincent, MAYBE for cost/simplicity (tooling)? or looks.
In the case of the H/D, must have been a specific reason for that one application, as it seems they didn't favorite it much, didn't adopt it for others.

AND JUST USING STANDARD ENGINEERING PRACTICES,
But it IS cool.
