Rear brace made from tough molded composite. Using the composite brace will make the car more flexible and more forgiving, thus making the car easier to drive. Recommended for bumpy tracks.
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V2 UPDATE: The front and rear braces have significant influence on chassis stiffness and this has great impact on the car handling under different track grip conditions. The composite braces have proven to be the most frequently used in most racing conditions and as such the design was modified and updated to make the braces stronger to withstand extreme conditions after big jumps, preventing tweaking or breakage.
Extra-robust composite braces are keyed to the chassis, guaranteeing overall chassis stiffness but still being flexible enough to allow the car to generate sufficient grip and provide the desired steering characteristics.