King PR2518-COPB-I 2.5 Inch Coilover Shock 18 Inch Stroke Piggyback Reservoir with Internal Bypass

The King PR2518-COPB-I is a high-performance 2.5 inch diameter coilover shock with an 18 inch stroke, featuring a piggyback reservoir design and advanced Internal Bypass (IBP) technology. This Performance Race series shock is engineered to deliver professional-grade damping control and exceptional ride quality for off-road trucks, pre-runners, and rock crawlers.

Internal Bypass Technology:

The IBP internal bypass system provides precisely tunable velocity-sensitive and position-sensitive damping in a compact monotube design. Using a full diameter piston with a secondary valving chamber mounted below it, fluid can bypass the primary piston through ports in the shock's hollow shaft. A tapered metering rod creates progressive damping as the shock compresses, allowing light valving at ride height for comfortable street driving while delivering substantial damping force at full compression to prevent bottoming during aggressive off-road use. This technology also provides a hydraulic bump stop effect in the final inches of travel.

Key Specifications:

• Shock body diameter: 2.5 inches
• Stroke length: 18 inches
• Extended length: 45.972 inches
• Compressed length: 28.346 inches
• Gas pressure: 150 PSI
• Piggyback reservoir design
• Sold without springs (custom spring rates specified separately)

Premium Construction Features:

• 4130 chromoly shock body with cadmium plating
• 6061 aluminum alloy piston
• Hard-chromed, micro-polished shaft with 100,000 PSI tensile strength
• Precision-honed cylinder bores (±0.001 inch tolerance)
• Long-wearing urethane seals
• PTFE-lined stainless steel spherical bearings
• Lightweight hard-anodized 6063 aluminum alloy reservoir

King Performance Race series shocks are hand-built in the USA and custom-valved to your specific vehicle and application requirements. These shocks incorporate both the coil spring perch and shock absorber in one space-saving package, making them ideal for custom suspension builds where packaging constraints exist. The piggyback reservoir design enhances heat dissipation and maintains consistent damping performance during extended high-speed runs or rock crawling sessions.