X Shock Hard Spring Yokomo YOKR12-37SH — Hard-Rate Coil for R/C Dampers  [YOKR12-37SH]

Heavy-duty coil for tougher damping

This RC-scale shock spring is intended for general R/C spring sets and suspension tuning. The Yokomo YOKR12-37SH X Shock Hard Spring offers a noticeably harder rate than soft or medium springs and is meant to modify suspension response rather than act as a load-bearing element.

Fitting is simple for anyone used to threaded dampers: disassemble the damper shaft assembly, slide the coil onto the shock body, reset preload and retainers, then check free travel and damping action. Only common shock tools and a tidy workspace are needed.

In setup terms, a hard-rate spring stiffens the ride, cuts down roll and squat, and increases resistance to compression. These changes affect both compression and rebound sensation, so select shock oil and piston combinations that complement the firmer coil to preserve balance.

Care advice: make single-step changes while tuning, test across the same surface, and log damper adjustments so you can return to a known setup. If the car becomes choppy over minor bumps after fitting a harder coil, try reducing preload or using slightly lighter shock oil before swapping springs.