Disc Brake

DISC BRAKE

A disc brake system stops the bicycle by squeezing brake pads against a metal disc (rotor) attached to the wheel hub, rather than against the rim of the wheel. Disc brakes have become the dominant brake standard on mountain bikes, gravel bikes, and increasingly on road bikes.

Advantages

• Consistent braking performance in wet conditions: The braking surface (rotor) is away from the tire and less affected by water and mud compared to rim brakes.
• Greater stopping power: Especially with hydraulic systems, less lever effort is needed for more braking force.
• Better modulation: Finer control over the amount of braking force applied.
• Less rim and tire size restriction: Wide tires can be used without affecting brake performance.

Disadvantages

• Heavier than rim brakes.
• More complex to service (especially hydraulic systems).
• Rotors and wheel hubs add weight and complexity to the wheel.
• Rotors can become contaminated with oil, significantly reducing performance.

Types

There are two main types of disc brakes:

• Mechanical disc brakes: Use a steel cable (like rim brakes) to actuate the caliper. More affordable, easier to field-service.
• Hydraulic disc brakes: Use hydraulic fluid in a sealed system. Superior feel, power, and modulation. Standard on quality mountain bikes.