TRAXXAS Unlimited Desert Racer Rear Spring Dampers 139mm UDR139R by GPM  [UDR139R]

Aluminum rear shock assemblies for TRX UDR

This rear spring damper set is made for the TRAXXAS Unlimited Desert Racer platform. The kit includes two aluminum-bodied rear dampers aimed at lowering internal friction and absorbing impact loads so the vehicle tracks with improved balance during off-road runs.

The upgrade follows a clear parts change: spring wire is increased from 1.8mm to 2mm while remaining compatible with standard springs if a softer or firmer rate is preferred, and shock shafts grow from 3.5mm to 5mm to better resist bending under load. The cylinder is aluminum and the spring retainer is shaped to seal tightly and help limit oil leakage during use.

These dampers are typically selected where stronger rear damping is needed for rough terrain and high-speed desert sections. Installation requires basic shock disassembly and reassembly, and tuning continues with shock oil, springs, and preload adjustments to match ride height and damping feel.

For builders after a firmer rear damping setup for the TRAXXAS UDR, these aluminum rear dampers provide thicker shafts and springs while keeping installation and tuning familiar to standard shock service.