Battery Area Mass Insert Compatible with TRF421X - Tamiya 3451597  [3451597]

Battery Bay Mass Insert for TRF421X

This RC-scale part is the Tamiya 3451597 battery weight, noted as part 42391, for use with the TRF421X chassis. It is designed to act as a mass insert in the battery area to influence handling and balance without modifying major chassis parts.

Fitment targets TRF421X layouts, so check your battery tray configuration before attempting installation. The unit sits in or near the battery bay to change the centre of mass for fine adjustments to front/rear bias and transient response during acceleration and directional changes.

Installation is simple on compatible TRF421X setups: remove body and battery, identify the specified battery-slot, place the weight as recommended, and fasten using the chassis mounting points or existing screws. Do not perform non-standard modifications to chassis hardware, and keep wiring and battery straps clear of the mass insert.

Tuning guidance: modest battery weight shifts affect understeer/oversteer balance and traction transition behavior more than outright grip. Add weight gradually and run repeatable tests on the same surface, noting positions for rollback. This part is meant for fine-tuning balance rather than altering structure.

For TRF421X drivers looking to tweak chassis behaviour, this battery weight offers a straightforward means to refine mass distribution without replacing main components.