These turbine-powered motorcycles from the movie Priest deserve a nod. They actually made a bunch with hidden regular motorcycle engines.
RYNO Motors' single-wheeled electric scooter is self-balancing, has a turning radius of zero when stopped, & only takes up about as much space as a folding bicycle -- so it's conceivable that commuters could bring one onto a train.
Afternoon Drive: Two-Wheeled Freedom Machines Photos) - two-wheeled freedom machine motorcycle Indian Motorcycles Harley-Davidson harley custom motorcycle custom bike chopper
Train Wreck, the Steam Engine Concept Motorcycle - autoevolution .Colby Higgins is a design student in Boston, and Train Wreck is his brainchild: just like the name suggests it, we're dealing with an amazing steam engine bike concept.
Yamaha Design AH A MAY concepts
Yamaha Root concept, created by musical instrument designers
Clint Eastwood on his 67 Norton motorcycle on the set of Where Eagles Dare, 1968