Like other types of vehicles, an all-terrain vehicle requires a braking system to slow or stop the machine during use. Hydraulic disc systems are the most common types of ATV brakes, and just about every ATV on the market will feature disc brakes. Some ATVs may also feature drum ATV brakes, but these are less common than disc brake setups. The specific components within each system can vary in materials and design, though the general function usually remains the same: a master cylinder is used to apply pressure to oil within a hydraulic line, which in turn actuates pistons in a brake caliper.
Metal discs must be mounted to the wheel of the ATV, usually around the hub. This metal disc is designed to work in conjunction with the brake pads, which will squeeze either side of the disc when activated. The disc usually features a series of holes that help keep the system cool during the high-friction braking process. If other styles of ATV brakes, such as drum brakes, are used instead of disc brakes, this disc will not be present on the hub. Instead, a thick metal drum will be mounted on the hub, and a wheel cylinder will activate the brake pads, pressing them outward against the inside of the drum.
Some ATV brakes feature a metal hydraulic hose in which brake fluid will be present. The metal lines are efficient at resisting damage from impacts, and the lines will not expand when pressure is placed on the fluid within. Other ATV systems may use lines made from plastic, braided steel, or other composite materials that are designed to resist swelling when the fluid inside is actuated. The lines must resist swelling to increase the amount of pressure transferred directly to the brake pistons within the caliper.
Variation in ATV brakes will often come in the form of various brake pad materials. Ceramic brake pads, asbestos brake pads, and semi-metallic brake pads are all fairly common choices. Choosing the right one usually depends on what types of conditions the ATV will be used in, what type of braking system is already present on the vehicle, and how much stopping power the rider wants in relation to the amount of pad wear that will occur over time. The price of the pads can vary as well; ceramic pads tend to be fairly expensive, while asbestos pads are usually cheaper.