Eibach 1200.250.0300S ERO Coilover Spring 12" x 2.5" ID 300 lb/in Silver

Vehicle Fitment

• Universal - not vehicle-specific; fits any coilover shock or suspension system that accepts a 2.50" inside diameter (64mm) coilover spring in a 12.00" (305mm) free length application
• The 2.50" ID / 12.00" length combination is used in higher-travel coilover systems across off-road racing, desert prerunner builds, rally, lifted truck performance, and long-stroke road racing applications; at 300 lb/in, this spring rate is appropriate for lighter vehicles or softer-tuned setups in these applications; verify your coilover's spring perch inner diameter and available shock stroke before ordering

Fitment Notes

• Inside diameter (ID): 2.50 inches (64mm) - the most broadly compatible coilover spring ID across performance and race coilover systems; confirm your coilover's spring perch inner diameter before ordering
• Free length: 12.00 inches (305mm) - this is a long spring relative to most performance street coilover kits (which typically use 6"-8" springs); 12.00" is common in high-travel coilover systems with extended shock bodies, bypass shocks, or suspension designs with wide perch-to-perch spacing; confirm your coilover's available stroke and perch-to-perch distance accommodate a 12.00" free-length spring at the desired installed ride height and preload
• Spring rate: 300 lb/in - a moderate rate within the 12.00" x 2.50" ID ERO family; at 300 lb/in on a 12.00" free-length spring, the application is typically front or rear coilover use on lighter prerunner builds, long-travel performance trucks, or applications where a soft spring rate is intentional to maximize terrain compliance while relying on the shock's damping to control body motion; for heavier builds or more body-motion control, higher rates in this same length and ID (350, 400, 500 lb/in and above) are available
• Silver powder coat finish - the "S" suffix designates the ERO (Race Off-Road) silver finish variant; silver identifies ERO springs across Eibach's off-road lineup, distinguishing them from the standard red ERS main springs used in circuit racing and performance street applications
• Sold individually - one spring per order; order the quantity required for your specific application

Features

• ERO (Race Off-Road) series - the ERO designation identifies this spring as part of Eibach's off-road-specific product line, engineered for the impact loading, high-frequency cycling, and environmental exposure of desert racing, prerunner builds, stadium off-road, and high-travel performance off-road builds; ERO springs are constructed with the surface treatment and winding geometry appropriate for sustained off-road duty cycles that are fundamentally more demanding than circuit racing or street use
• 2.50" inside diameter - the most universally compatible coilover spring bore in the aftermarket performance and race suspension industry; fits the broadest range of coilover kits, from entry-level performance street systems through professional race coilover applications, making this the most versatile ID in Eibach's ERO lineup
• 300 lb/in linear rate - the rate is constant across the full compression stroke from free length to block, producing predictable, mathematically consistent spring force at every point of travel; a linear rate simplifies suspension modeling and setup changes - the effect of a rate change is directly proportional and calculable; at 300 lb/in on a 12.00" free-length spring, this combination targets applications requiring a soft initial spring rate with maximum available travel before block, making it particularly suitable for long-travel builds where wheel compliance over terrain is a priority
• Long free length for maximum stroke applications - the 12.00" free length is the longest standard length in the 2.50" ID ERO family that is commonly used in dual-shock or bypass shock setups; longer springs require proportionally less preload for a given ride height, which preserves more available spring travel and keeps the spring closer to its natural frequency for better terrain compliance; in long-travel prerunner and desert race applications, the 12.00" length is selected specifically to take advantage of the shock's full stroke while maintaining adequate spring guide contact length for lateral stability
• Shot-peened surface treatment - the spring wire is shot-peened before powder coating; shot peening introduces compressive residual stress at the wire surface, closing fatigue micro-cracks before they can propagate under high-cycle loading; in off-road and race applications where the spring may cycle millions of times per season over rough terrain, this treatment is the primary factor enabling ERO springs to maintain consistent rate and resist cracking or taking a permanent set
• Preset to block - every Eibach ERO spring is factory-compressed to block before shipment, eliminating initial sag and ensuring the rated 12.00" free length and 300 lb/in rate are delivered from the very first installation with no break-in period
• Individually rate-tested - each spring is measured against its rated 300 lb/in value on Eibach's rate testing equipment before leaving the factory; rate consistency is guaranteed spring-to-spring, ensuring the installed spring matches the setup engineer's specification
• Silver powder coat finish with imprinted part number - the ERO silver finish provides corrosion resistance appropriate for off-road and prerunner environments (mud, water, sand, rock dust); the spring rate and part number are stamped directly on the spring body for correct identification after packaging is removed or springs are mixed in a shop inventory

Specifications

• Part Number: 1200.250.0300S
• Manufacturer: Eibach
• Series: ERO (Eibach Race Off-Road)
• Spring Type: Main coilover spring, linear rate
• Free Length: 12.00 inches (305mm)
• Inside Diameter (ID): 2.50 inches (64mm)
• Spring Rate: 300 lb/in (5.36 kg/mm)
• Finish: Silver powder coat
• Surface Treatment: Shot-peened
• Preset: Yes - factory preset to block
• Quantity: Sold individually (1 spring)

Included Components

• 1x Eibach ERO Race Off-Road Coilover Spring - 12.00" x 2.50" ID x 300 lb/in (silver)

Product Description

The Eibach 1200.250.0300S is a single ERO (Race Off-Road) series coilover spring - the 12.00-inch free length, 2.50-inch inside diameter, 300 lb/in linear-rate variant from Eibach's off-road coilover spring lineup. The "S" suffix designates the silver powder coat finish that identifies all ERO series springs across Eibach's catalog. At 12.00 inches of free length and 300 lb/in, this spring targets long-travel coilover applications where a soft, compliant spring rate is paired with a long shock stroke - a setup philosophy common in desert racing prerunner builds, high-travel lifted performance trucks, and off-road race vehicles where terrain compliance over rough surfaces is prioritized alongside shock damping for body control.

The 2.50-inch inside diameter is the most universally compatible coilover spring bore in the aftermarket and race coilover market, fitting the broadest range of shock bodies and spring perches from professional race coilover systems through performance street kits. At 300 lb/in, this spring is at the softer end of the rate range for the 12.00" x 2.50" ID family - adjacent rates available in this same length include 125, 250, 350, 400, 500, 600, and 700 lb/in, giving suspension engineers wide latitude to tune the initial spring rate for specific vehicle weights, motion ratios, and terrain conditions. The longer 12.00" free length compared to the more common 8"-10" prerunner spring lengths produces proportionally less preload for a given ride height, which keeps more spring travel available in the compression direction and positions the spring nearer its natural resonant frequency for better small-input terrain compliance.

Shot peening closes fatigue micro-cracks in the wire surface before they can propagate under high-cycle off-road loading. Factory preset-to-block eliminates initial sag. Individual rate testing guarantees the installed spring matches the specification. The spring rate and dimensions are stamped on the silver powder-coated body for shop identification. Sold individually.