A bicycle works with rotating rubber wheels, drive chains and gears driven by pedals for speed, brakes to slow and handlebars to steer. The bicycle wheel also has spokes to distribute the forces of movement evenly around its center, or hub.
The pedals generate the power and accelerate the bicycle forward by turning the wheels. Power is transmitted from the pedals to the wheels with the drive chain. The forces acting upon each rubber tire, such as the weight of the rider and forces of road contact, braking and pedaling, are lessened by the tension of the spokes. The brakes work using a brake cable and springs, which absorb the forces of motion. Tires have different treads to add grip and friction, depending on the road surface. Gears and gear shifters allow riders to increase their speed without having to pedal faster.