Good morning, everyone. Today we're going to look at the history of the bicycle. Now, you might think that the bicycle has always been a simple, efficient machine, but its development was actually quite complex. The first two-wheeled vehicle, called the 'draisine', was invented in 1817 by a German baron. It had no pedals; riders pushed their feet against the ground. Then, in the 1860s, pedals were added to the front wheel, creating the 'boneshaker'. This was very uncomfortable due to its solid rubber tires and rigid frame. It wasn't until 1885 that the 'safety bicycle' appeared, with a chain drive and two equal-sized wheels, which made riding much safer and more practical.
❓ Согласно лекции, в чём заключался главный недостаток велосипеда «костотряс»?