New precision-designed composite chassis frame with split design has a separate front part and rear chassis plate. Compatible with both XB4 and XB4 2WD. The split design allows the entire rear suspension to be mounted in either standard position using the rear chassis plate, or to be placed lower by mounting the rear suspension directly to the aluminum chassis. The direct mounting of the rear suspension increases traction and is recommended for low-traction tracks; optional rear suspension holders 363311 & 363321 are required.Multi-Flex settings are quick and easy to change, and the chassis houses the main components of the car. Front, center, and rear drivetrain bulkheads are keyed to the frame, and it provides smart locations for all required electronics. The chassis tray design features reinforcement braces in both lengthwise and lateral directions. The tray design ensures perfect protection on bottom and sides without requiring additional components. The rear of the chassis features positions for additional optional weights which allow for quick & easy weight balance adjustment.