While there are several types of brake callipers available, two common configurations are radial mount and axial mount brake callipers. These calliper designs differ in their installation method, construction, and overall performance characteristics. Let’s delve into the details of radial mount and axial mount brake callipers, highlighting their unique features, benefits, and applications.
Radial Mount Brake Callipers:
Radial mount brake callipers derive their name from the way they are mounted on the vehicle upright. Unlike axial mount callipers, which are mounted parallel to the axle, radial mount callipers are attached perpendicular to the axle, with their mounting bolts extending radially outward. This design offers several advantages:
1. Rigidity and Stiffness: Radial mount callipers are known for their exceptional rigidity. The radial mounting configuration ensures that the calliper remains securely fixed in place, minimizing flex and providing optimal braking performance. This increased stiffness translates into improved brake pedal feel, better modulation, and enhanced overall braking efficiency.
2. Heat Dissipation: The radial mount design facilitates better heat dissipation compared to axial mount callipers. The calliper’s radial position allows for improved airflow and cooling around the brake pads and rotors, reducing the risk of brake fade during intense braking situations. This cooling advantage is particularly important in high-performance and track-oriented vehicles.
3. Enhanced Braking Power: Due to their robust construction and increased rigidity, radial mount callipers can generate higher clamping forces. The improved leverage and mechanical advantage result in greater braking power and shorter stopping distances, making them ideal for sports cars and performance-oriented vehicles.
Looking closely you will see the lockwire on the mounting bolts.
Axial Mount Brake Callipers:
Axial mount brake callipers, also known as floating callipers, are installed parallel to the axle and commonly include sliding pins. While they have a different installation mechanism compared to radial mount callipers, axial mount callipers have their unique set of advantages:
1. Simplicity and Cost-Effectiveness: Axial mount callipers are simpler in design and easier to manufacture, making them a cost-effective solution for vehicle manufacturers. The sliding pin mechanism allows for easier installation and maintenance, simplifying brake pad replacement and servicing.
2. Space Constraints: In certain applications where space is limited, such as smaller vehicles or vehicles with tight wheel clearance, axial mount callipers provide a compact solution. Their parallel mounting orientation allows for better integration within the wheel assembly, ensuring optimal fitment in tight spaces.
Often a Big Brake Kit will use a radial mount calliper and bones (adaptors) to convert from axial mount to radial mount.
To sum this all up. Radial mount is performance orientated while axially mounts are the poor cousin used by OEM on many cars to keep costs lower. In some cases OEM will use opposing pistons calliper designs which often have good rigidity, stiffness and air flow characteristics. While not a true radial mount they are a good engineering compromise.