Skull helmets by themselves get a +2 biker score in my book. Add in another dimension to the custom job?
Badass Level 10.
My Favorite 3d Motorcycle Helmets by Devil Tail Customs:
Rob Baer credits the custom tail on his motorcycle for a good portion of the inspiration, and has since expanded into custom helmet artwork. Be sure to check out all the 3D Motorcycle Helmet Designs and Custom Art over at his site: Devil Tail Customs