TRF421X Weight Insert for TRF421X Chassis - Tamiya 3451597  [3451597]

TRF421X Weight Insert Details

This RC-scale accessory is the Tamiya 3451597 battery weight, referenced as part 42391, intended for use with the TRF421X chassis. It serves as a dedicated battery-area mass insert to influence balance and handling without altering primary chassis components.

Compatibility is limited to TRF421X layouts, so confirm your battery tray arrangement before fitting. The insert is designed to sit in or adjacent to the battery bay to tweak the centre of mass for fine tuning of forward/rear bias and transient response during acceleration and direction changes on track.

Fitting is straightforward on supported TRF421X layouts: remove the body and battery, find the designated battery-slot area, seat the weight in the recommended position, and secure it with existing chassis screws or mounting points. Do not modify chassis hardware beyond normal servicing, and make sure wiring and battery straps are routed clear of the added mass.

Tuning notes: small shifts in battery-area mass alter understeer versus oversteer balance and affect traction transitions more than raw grip. Add mass incrementally and test on consistent surfaces, recording positions so you can revert settings. This part is intended for precise RC-scale balance adjustments rather than structural changes.

For TRF421X owners seeking measured changes to chassis behaviour, this battery weight provides a direct method to adjust mass distribution without replacing major components.