Progressive Suspension 512-1004B Series Rear Shock Absorbers - 512

The Progressive Suspension 512-1004B is a direct-fit rear shock absorber from the legendary 512 Series — one of the most trusted upgrades in the motorcycle aftermarket. Designed to replace worn OEM shocks, the 512 Series delivers a noticeably smoother, more controlled ride whether you're cruising solo or carrying a passenger and gear.

Key Features:

• Progressive Rate Springs — Dual-rate spring design provides a plush, comfortable feel at low loads while firming up progressively under heavier loads for improved stability
• 5-Position Preload Adjustment — Easily dial in the correct spring preload for solo riding or two-up/loaded configurations without tools
• Velocity-Sensitive Damping — Damping force automatically adjusts based on the speed of suspension movement, absorbing small bumps gently while controlling large impacts firmly
• Gas-Charged Design — Pressurized nitrogen gas charge prevents aeration and fade, delivering consistent damping performance mile after mile
• Shock Sox Included — Protective fabric boots cover the springs and preload adjusters to shield them from road grime, debris, and moisture
• Black Finish (1004B) — The "B" suffix denotes a sleek black spring and body finish to complement dark or blacked-out motorcycle styling

Progressive Suspension's 512 Series shocks are sold as a pair and are engineered to be a straightforward bolt-on replacement. The combination of progressive spring rate technology and gas-charged damping makes the 512-1004B a significant performance upgrade over standard OEM rear suspension components.