the first motorcycle in the world, the steam powered bike Louis Perreaux invented and built between 1868 and 1873

It is on display in the lobby of the Orne hotel, from June to October. 

It featured a brass-plated single-cylinder steam engine with an alcohol fuel burner under the saddle of a French-made Michaux velocipede bicycle. Drive was by twin belts, and it was capable of about 9 miles per hour

https://www.facebook.com/isabelle.bracquemond.7
http://www.motomag.com/Exposition-le-departement-de-l-Orne-fete-l-inventeur-de-la-moto.html#.V3xp57grKUl
https://en.wikipedia.org/wiki/Michaux-Perreaux_steam_velocipede

Of course, the Roper steam motorcycle is also claimed to be an 1867 or 68 invention.
Both the Perreaux and Roper machines have been assigned years of origin of 1867, 1868, and 1869 by different authorities, and which combination of these three years is given to the two steam motorcycles determines whether it was a tie, or whether one can be called the first.