Conventional Spring 20in x 5in x 100lb

The Conventional Spring 20in x 5in x 100lb from SWIFT SPRINGS is a precision-engineered coil spring designed for suspension tuning on performance and modified vehicles. Built for automotive enthusiasts who demand predictable handling and load support, this rear spring addresses the core challenge of maintaining proper ride height and spring rate under modified vehicle weight. Whether you're upgrading a lowered car, compensating for added power-plant mass, or fine-tuning suspension geometry, a properly rated coil spring is non-negotiable for safe, controlled cornering and braking response.

This spring features a 100 lb/in spring rate with a 20-inch free length and 5-inch outer diameter, delivering consistent compression characteristics across the suspension travel range. The black powder-coated steel construction resists corrosion and road salt degradation, critical for longevity in harsh climates. The conventional (linear) spring design provides predictable force curves—unlike progressive springs that stiffen at height—making it ideal for street-driven builds where consistent bump compliance and bottoming resistance matter equally. Weighing 8.42 lbs, it integrates seamlessly into rear suspension packages without compromising unsprung mass significantly.

Rear spring replacement is essential when upgrading engine displacement, adding forced induction, installing heavy aftermarket components, or leveling a chassis after front modifications. A 100 lb/in rate suits mid-range performance builds and daily-driven modified vehicles where aggressive stiffness isn't required but factory springs are insufficient. Mechanics and tuners specify SWIFT SPRINGS coils for their dimensional consistency and repeatability—critical factors when dialing in anti-squat geometry or load-sensitive suspension behavior. Installation requires removal of old springs, proper spring compressor equipment, and verification that new springs match OEM-equivalent seat diameter specifications for safe seating.