Skis, snowboards, and ski bikes are all propelled by the downward pull of gravity. At the top of a mountain, skiers, snowboarders, and ski bikers have potential energy because of their raised position. When they push off downhill, gravity transforms this stored energy into kinetic energy, or the energy of motion. That causes their snowboards, skis, or ski bikes to accelerate—or change speed—moving faster and faster down the mountain.
Ski bikers have some key advantages over skiers and snowboarders, though. Riding seated lowers a biker’s center of mass—the point around which an object’s mass is concentrated. This makes it easier to balance without tipping over. A ski bike is also easier to steer—a rider can just turn the handlebars and lean to the side, like on a regular bike. Also like a typical bike, a ski bike has a rigid metal frame with a suspension system, such as shockabsorbing springs. They help the bike absorb impacts as it goes over bumps.