Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, many people think the bicycle was invented in the 19th century, but its origins actually go back further. The first two-wheeled vehicle, called a 'Draisine' or 'hobby horse', was invented by a German baron, Karl von Drais, in 1817. It had no pedals; riders pushed their feet against the ground to move. Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede'. However, this design was uncomfortable and hard to ride. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels became popular, which is the basis for modern bicycles.
❓ Theo bài giảng, vấn đề chính của xe đạp velocipede là gì?