4-piston brake caliper Radial RPG MK2

With this caliper, RPG once again stands out from the competition.
Thanks to a larger selection of colors and new manufacturing technologies, we offer you this well-known and established technology at the best price-performance ratio.

Improvements compared to its predecessor

When developing the well-known 4-piston design, our greatest aim was to retain the existing design, as it has been established for many years and the scene knows exactly: "what, how, where" fits. Nevertheless, we wanted to improve stiffness and durability . To achieve this, we use a forging process for the MK2 version. A block of high-strength aluminum alloy, from the aerospace industry, is pressed into the shape of the brake caliper under tons of pressure and heat. This causes the material structure to become much more dense and the material becomes even stronger. This semi-finished brake caliper is then precisely milled to its final shape using a 5-axis CNC machine.

Even if the design has remained the same, the new look is still not neglected. Thanks to a new anodizing process, the colors now appear even stronger and shinier. Almost like colored chrome.

In order to improve user-friendliness and eliminate unnecessary sources of error, we are now eliminating our additional ventilation valve on the back. A new CNC milled stainless steel banjo screw with an integrated vent valve not only forms the highest point, which is the best way to vent anyway, but also looks great with its color anodized valve cap .

The 4 brake pistons are now made of steel and receive a special, low-friction coating, which also serves as corrosion protection. The steel pistons ensure longer life and transfer less heat to the brake fluid than other pistons.

Why a 4-piston brake caliper?

1. High-performance and precise pressure point. Whether on the road or the race track, the 4-piston brake caliper enables more precise braking, which means you can delay the braking point to the last detail.
2. Longer lifespan and higher heat resistance. Due to the larger area and the better distribution of forces, the energy is distributed better. The resulting heat is released more quickly into the surrounding air through the highly conductive aluminum.
3. Better controllability compared to 2-piston brake calipers. The higher friction surface and twice the number of pistons not only generate more braking power, but the brake can also be actuated more sensitively.

scope of delivery

-Our new brake calipers are delivered from the factory with semi-metal brake pads. These are a lot sportier than organic pads and still don't need as long a warm-up phase as sintered pads.
-2x new, high-quality copper sealing rings
-1x milled stainless steel banjo screw with integrated vent valve and color anodized valve cap
-Furthermore with the beautiful and well-known RPG wooden box, which is ideal for storage after shipping.

Accesories

The hole spacing for mounting remains at 82mm as usual. This means it still fits all possible 4-piston adapters from RPG, Stage6, Voca, etc.
You can find adapters from RPG here in the shop: Brake System
Brake pads are also available from different manufacturers. The rubbers from Stage6, RPM, Voca and much more also fit. We of course recommend our RPG brake pads. Our double-sintered brake pads offer the best price-performance ratio and you can look forward to twice the braking power .
This brake caliper works best with brake pumps that have a 14mm piston diameter.

Vent

As with its predecessor, we do not provide detailed instructions for venting for liability reasons. However, the same tips that we have always had for you apply here:
-Buy enough DOT 4 brake fluid.
-Connect a clear hose securely to the vent valve and hang the end in a clean glass.
-Flood the system well when filling for the first time. So that you don't need 5 liters of brake fluid, pour 3/4 of the full glass back into the bottle.
-Never open the valve while the hose is in contact with air.
-After bleeding, fix the brake lever firmly. The brake system, which is now under pressure, is no longer touched overnight. The next day, the brake fluid container is opened and the brake lever is relaxed again. A few final air bubbles will escape upwards and the venting process has been perfected.