Found this thread in the softail section of a guy putting a sports bike rear on a fatboy. Worth a look if you like seeing something different.
https://www.hdforums.com/forum/showthread.php?p=10362531#post10362531

 

That just looks bizarre.

 

His other builds look pretty good. This build should be interesting! The vision he has for it sounds pretty innovative. Should look pretty cool when its done.

 

Very cool! Thanks for sharing that, I don't venture into that forum.