Sylvester Howard Roper (November 24, 1823 – June 1, 1896)[1][2] was an American inventor and a pioneering builder of early automobiles and motorcycles from Boston, Massachusetts.

[1] Roper left Francestown at a young age and worked as a machinist, first in Nashua, then in Manchester, New York,[17] and Worcester.

[20] Roper's work eventually came to the attention of other inventors and engineers of the area, including Elias Howe, Alvan Clark, Christopher Miner Spencer.

[14] Roper and Christopher Miner Spencer were granted a joint patent for a repeating shotgun mechanism on April 4, 1882.

[1][8] On June 1, 1896, Roper rode one of his later velocipede models, a Pope Manufacturing Company Columbia bicycle with a steam engine added,[20] to the Charles River bicycle track, near Harvard Bridge, Cambridge, Massachusetts, where he made several laps, pacing bicyclists there, including professional rider Tom Butler[21] who could not keep up with the steam powered machine.

[8] Roper was clocked at 2 minutes 1.4 seconds for the flying mile, for a top speed 40 mph (64 km/h)[8][20] He was seen to be unstable and then fall on the track, suffering a head wound, and was found dead.