Cyclers
Invention
Wheeled human-powered vehicles had been invented before the bicycle and dated back to the 15th century when Giovanni Fontana created a four-wheeled vehicle that had a continous rope connected via gears to the wheels. Other advancements in wheeled vehicles (predecesors to the modern bicycle) happened in the centuries after, but bicycles as we know them were not invented until the 19th century. In 1817, German aristocrat and inventor Karl von Drais created a steerable two-wheeled contraption and other inventors improved on his work until it evolved into the modern bicycle.
Popularity
Interest in bycicles exploded in the second half of the 19th century as bicycles were used for recreation and were associated with freedom, especially for women. Four key aspects made bicycles very popular: speed, safety, steering, and comfort. By the beginning of the 20th century, bicycling was a common mode of transportation and clubs emerged all over the country. A popular and important association that was born from the cycling craze was the League of American Wheelmen which played a very important role in the movement for the improvement of road conditions across the nation.
Motorcycles
Motorcycles are an invention of the 19th century as well, and like bikes, they gradually evolved over time. The early version of the motorcycle was steam-powered and called the "velocipede" by its creator American Sylvester Howard Roper (credited to have created the first steam-engine car). Over time other self-propelled models were invented but German Gottlieb Daimler is famously known to be the first to use a gasoline-powered engine in 1885 in a self-propelled bycicle, this was the beginning of modern motorcycles.