Mugen Seiki MRX4 Brake Disc by 3Racing MRX4-21/GO  [MRX4-21/GO]

Brake disc for MRX4 series

This brake disc is an RC-scale replacement part intended for use with Mugen Seiki MRX4 and MRX4-R chassis, supplied under 3Racing part number MRX4-21/GO. It is offered as a direct-fit spare to restore or modify rear braking components on 1/10 on-road models that use the MRX4 family mounting pattern.

Installation notes: verify rotor alignment with the hub and ensure fasteners are torqued to your existing hardware recommendations, replacing hardware if worn. Fit one side first, check rotor runout, then install the opposite side and test free rotation before reassembling the drivetrain. Standard hand tools used on MRX4 assemblies are sufficient for fitment.

Tuning role: swapping brake discs affects pedal feel and brake modulation at the wheel hub level, which informs setup choices for brake bias and diff tuning on track. Use matched pairs and test increments on short runs to observe changes in stopping response and corner entry behaviour.