In the video, we see a close-up of a bicycle's gear system. The gears are made of metal and are connected to a chain that is also made of metal. The gears are spinning, and we can see the chain moving along them. The bicycle itself has a red frame, and we can see the pedals in the background. The gear system is complex, with multiple gears of different sizes. The video provides a detailed look at how the gears and chain work together to propel the bicycle forward.