Eibach 1800.300.0300S ERO Coilover Spring 18" x 3.0" ID 300 lb/in Silver

Vehicle Fitment

• Universal - not vehicle-specific; fits any coilover shock or suspension system that accepts a 3.00" inside diameter (76mm) coilover spring in an 18.00" (457mm) free length application
• The 3.00" ID / 18.00" length at 300 lb/in is a very long, moderate-rate spring combination used in the highest-travel off-road racing and prerunner coilover applications; at this free length, the spring is intended for extended-body bypass or reservoir coilover shocks with 18"+ body lengths common in desert racing and long-travel performance builds; verify your coilover's spring perch inner diameter and available shock stroke before ordering

Fitment Notes

• Inside diameter (ID): 3.00 inches (76mm) - a large-bore spring ID used in off-road racing coilover systems with larger shock bodies than the 2.50" ID standard; the 3.00" ID is standard in heavy-duty bypass shock builds and many long-travel prerunner coilover setups using 3" spring perches; confirm your coilover's spring perch inner diameter before ordering
• Free length: 18.00 inches (457mm) - among the longest standard lengths in the 3.00" ID ERO family; at 18.00", this spring is designed for extended-body coilover shocks in long-travel desert racing, Stadium Super Truck, full-size prerunner, and long-stroke off-road competition applications; confirm your coilover's available compression stroke and perch-to-perch mounting distance accommodate an 18.00" free-length spring at the desired installed ride height and preload
• Spring rate: 300 lb/in - a moderate rate for the 18.00" x 3.00" ID ERO family; at 300 lb/in on an 18.00" spring, this is appropriate for lighter-to-moderate-weight off-road vehicles, front coilover applications where a softer spring rate is required for terrain compliance, or setups where the 10.80 inches of active travel is the primary design target and a moderate rate is acceptable for the vehicle's weight and loading conditions; heavier builds or applications requiring greater spring force should consider higher rates in this same length and ID
• Block height: 7.20 inches (183mm) - the spring coils fully solid at this height; the coilover's bump stop must engage before this point in normal use; verify adequate bump stop clearance at full shock compression
• Maximum travel: 10.80 inches (274mm) - from free length to block; at nearly 11 inches of active spring travel, this is one of the longest available travel ranges in the 3.00" ID ERO family, enabling proportionally long wheel travel when paired with the appropriate coilover geometry and motion ratio
• Silver powder coat finish - the "S" suffix designates the ERO (Race Off-Road) silver finish; distinguishes ERO springs from the standard red ERS main springs
• Five-Year Warranty - Eibach's warranty covers defects in material and workmanship (other than coatings) when used on passenger cars and light duty (class 1-3) trucks under normal operating conditions
• 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 coilover spring line, engineered for the sustained high-amplitude impacts, high-frequency cycling, and environmental exposure of desert racing, long-travel prerunner builds, and stadium off-road applications; at 18.00" of free length and 3.00" of inside diameter, this spring is positioned at the large-format end of the ERO catalog, targeting the longest-travel coilover configurations in the lineup
• 3.00" inside diameter - a heavy-duty spring bore used in off-road coilover systems with larger-diameter shock bodies and spring perches than the 2.50" standard; the 3.00" ID provides increased spring-to-body lateral clearance and greater spring stability under the side-loading conditions of jump landings and off-camber terrain, while remaining lighter than the largest 3.75" ID variants
• 300 lb/in linear rate - the rate is constant throughout the full 10.80-inch active travel stroke, producing predictable, consistent spring force at every point of suspension compression; at 300 lb/in on this 18.00" spring, the block load is 3,242 lbs - moderate force capacity appropriate for lighter purpose-built race vehicles and lighter full-size prerunner builds; heavier applications in this length should step up to the 350, 400, 500 lb/in or higher variants in this same 18.00" x 3.00" family
• Exceptional active travel of 10.80 inches - the 7.20-inch block height on an 18.00" spring yields 10.80 inches of working compression travel before the spring coils solid; this is an extremely long active travel window, exceeded in practical terms only by softer rates at this free length (the 100 lb/in variant delivers 12.67" of travel); 10.80 inches of spring travel enables very long suspension wheel travel at reasonable motion ratios, making this spring appropriate for builds targeting 15"+ of total wheel travel
• Block load of 3,242 lbs - at 300 lb/in, the spring generates 3,242 lbs (14,421 N) of compressive force when coiled solid; the coilover's bump stop must engage well before this load threshold in normal operating conditions to protect the shock
• Shot-peened surface treatment - the spring wire is shot-peened before silver powder coating, closing fatigue micro-cracks and dramatically extending service life under repeated high-amplitude impacts and high-cycle loading in off-road environments
• Preset to block - every Eibach ERO spring is factory-compressed to block before shipment, ensuring the rated 18.00" free length and 300 lb/in rate are delivered from the first installation with no break-in period
• Individually rate-tested - each spring is measured against its rated 300 lb/in value before leaving Eibach's factory; rate consistency is guaranteed spring-to-spring
• Silver powder coat finish with imprinted part number - the ERO silver finish provides corrosion resistance against mud, water, sand, and debris in off-road environments; the spring rate and part number are stamped directly on the spring body for identification after packaging is removed

Specifications

• Part Number: 1800.300.0300S
• Manufacturer: Eibach
• Series: ERO (Eibach Race Off-Road)
• Spring Type: Main coilover spring, linear rate
• Free Length: 18.00 inches (457mm)
• Inside Diameter (ID): 3.00 inches (76mm)
• Spring Rate: 300 lb/in (5.36 kg/mm)
• Block Height: 7.20 inches (183mm)
• Maximum Travel: 10.80 inches (274mm)
• Block Load: 3,242 lbs (14,421 N)
• Weight: 9.92 lbs (4.50 kg)
• Finish: Silver powder coat
• Surface Treatment: Shot-peened
• Preset: Yes - factory preset to block
• Warranty: Five-Year Warranty (material and workmanship defects, coatings excluded)
• Quantity: Sold individually (1 spring)

Included Components

• 1x Eibach ERO Race Off-Road Coilover Spring - 18.00" x 3.00" ID x 300 lb/in (silver)

Product Description

The Eibach 1800.300.0300S is a single ERO (Race Off-Road) series coilover spring - the 18.00-inch free length, 3.00-inch inside diameter, 300 lb/in linear-rate variant from Eibach's off-road coilover spring lineup. At 18.00 inches of free length with a 7.20-inch block height, this spring delivers 10.80 inches of active compression travel - nearly 11 inches of working spring stroke before coiling solid. This exceptional travel-to-length ratio positions this spring at the long-travel end of the ERO catalog, intended for extended-body bypass or reservoir coilover shocks in the highest-travel desert racing, long-stroke prerunner, and stadium off-road applications.

The 3.00-inch inside diameter is a heavy-duty spring bore used in off-road coilover systems with larger-diameter shock bodies than the more common 2.50" ID standard, providing additional spring-to-body clearance and lateral stability under the dynamic loading of off-road racing. At 300 lb/in over 10.80 inches of travel, the 3,242-lb block load is moderate by the standards of this spring family - appropriate for lighter purpose-built race vehicles or front coilover applications on full-size prerunner builds where spring compliance over terrain is prioritized. Heavier vehicles or applications requiring stiffer body control should step up to the 350, 400, 500, or 600 lb/in variants in this same 18.00" x 3.00" family.

Shot peening, factory preset-to-block, individual rate testing, and the Five-Year Warranty (excluding coatings) are standard across every Eibach ERO spring. The spring rate and dimensions are stamped on the silver powder-coated body for shop identification. Sold individually.