Coil Over Spring Rubber Blue 50

The LONGACRE Coil Over Spring Rubber Blue 50 is a precision polyurethane spring insert engineered for suspension tuning on race cars and high-performance vehicles. This 50-durometer rubber isolator fits coil-over suspension systems with spring diameters between 2.5 and 2.625 inches, providing a critical interface between the coil spring and shock tower or lower control arm mounting points. The 0.75-inch height and medium-hard durometer rating make this component essential for drivers seeking consistent suspension geometry and reduced spring vibration during both road and track use.

At 50 durometer, this spring rubber offers a balance between compliance and support. Unlike softer polyurethane compounds, the 50-durometer specification resists excessive deflection under load while maintaining enough elasticity to absorb minor shocks and vibration harmonics. The polyurethane construction resists degradation from oils, heat, and UV exposure far better than rubber compounds, extending service life on vehicles exposed to high ambient temperatures or harsh storage conditions. The blue color coding follows industry convention for durometer identification, allowing technicians to verify the correct stiffness at a glance during suspension assembly.

This isolator is intended for oval-track racers, road-course competitors, and street-performance enthusiasts building or refreshing independent coil-over suspension systems. It addresses a specific tuning requirement: managing spring preload, ride height adjustment, and vibration isolation without replacing the entire shock or spring assembly. LONGACRE spring rubbers are commonly selected when original equipment isolators have hardened or compressed, resulting in inconsistent ride height or clunking at the mounting points. Proper installation requires the isolator to be positioned between the spring coil and its mounting surface, ensuring even pressure distribution across the 0.75-inch contact face.