Rear Shock Absorber - HD 817

Item Summary S36DR1 type About the Product hlins STX 36 Twin Rear Shock Absorber Set HD 817 305 mm for Harley-Davidson Dyna FXD Series (19912017) Product Overview Upgrade the suspension performance of your Harley-Davidson Dyna with the hlins HD 817 STX 36 Twin Rear Shock Set. Designed specifically for 19912017 Dyna FXD models, the HD 817 combines classic styling with modern suspension technology, delivering superior ride comfort, improved stability, and enhanced rear-wheel traction without compromising the iconic appearance of your motorcycle. Built around hlins' proven S36DR1 monotube design, the HD 817 features adjustable rebound damping and mechanical spring preload adjustment, providing riders with the ability to fine-tune suspension performance for individual riding styles and varying load conditions. The integrated gas reservoir maintains a slim, factory-inspired profile while delivering the consistent damping performance that has made hlins a benchmark in motorcycle suspension worldwide. Key Features Genuine hlins STX 36 Twin Rear Shock Absorber Set hlins Part Number: HD 817 Type Code: S36DR1 Designed for Harley-Davidson Dyna FXD models 305 mm (12-inch) eye-to-eye length Single Tube (STX) monotube high-pressure gas design 36 mm piston diameter Adjustable rebound damping Adjustable mechanical spring preload Integrated internal gas reservoir for a clean appearance Precision hydraulic damping system Fully rebuildable and serviceable Manufactured in Sweden Sold as a matched pair STX 36 Single Tube Technology The HD 817 utilizes hlins' Single Tube Technology (STX), incorporating a 36 mm piston operating within a high-pressure nitrogen-charged monotube shock body. This advanced design separates hydraulic oil from the gas chamber, minimizing cavitation and maintaining consistent damping characteristics even under prolonged or aggressive riding conditions. Compared to conventional OEM shocks, the STX 36 system provides: Improved hydraulic control Reduced suspension fade Superior heat dissipation Better rear wheel traction Increased chassis stability Enhanced rider confidence More predictable handling characteristics Every application is specifically valved and tested to suit Harley-Davidson Dyna chassis dynamics, providing a substantial improvement in comfort and control. Adjustable Rebound Damping The HD 817 features an externally accessible rebound adjuster that allows riders to precisely control suspension extension speed after compression. Proper rebound tuning improves: Rear tire grip Corner exit stability Chassis composure Ride quality over uneven pavement Suspension recovery over successive bumps Overall motorcycle balance This simple adjustment enables riders to tailor the suspension to personal preference and road conditions. Adjustable Spring Preload Mechanical spring preload adjustment allows proper suspension sag setup for varying rider weights and loading conditions. Correct preload adjustment provides: Improved steering geometry Enhanced cornering stability Better braking performance Increased ground clearance Reduced bottoming Improved passenger comfort Proper sag adjustment ensures the suspension operates within its intended range for maximum performance and ride quality. Slim Integrated Reservoir Design Unlike piggyback reservoir models, the S36DR1 integrates the gas reservoir within the shock body, creating a clean, classic appearance while retaining the benefits of high-pressure gas technology. This streamlined configuration is ideal for riders seeking: Traditional Harley styling Simplified installation Reduced visual clutter Excellent ride comfort Outstanding long-term reliability The result is premium suspension performance with an OEM-inspired aesthetic. Premium Engineering Every hlins STX 36 shock is manufactured using premium materials and precision machining processes refined through decades of championship-winning motorsport development. Construction features include: CNC-machined aluminum shock bodies Hard-anodized corrosion-resistant surfaces Precision-ground piston rods Low-friction seal head assemblies High-pressure nitrogen charging Precision shim-stack valving Premium hlins suspension oil Replaceable internal wear components The fully rebuildable architecture ensures long service life and allows factory-level performance to be restored through routine maintenance. Performance Benefits Improved Ride Comfort The advanced hydraulic damping system absorbs road imperfections more effectively than stock suspension, reducing harshness and rider fatigue. Enhanced Stability Controlled suspension movement minimizes chassis pitch and oscillation during acceleration, braking, and cornering. Increased Rear Tire Traction Improved wheel control helps maintain consistent tire contact with the road surface for enhanced grip and confidence. More Predictable Handling The motorcycle responds more accurately to rider inputs, creating smoother transitions and improved overall handling characteristics. Reduced Suspension Fade The high-pressure monotube design maintains consistent damping performance under extended riding and elevated operating temperatures. Technical Specifications Specification Details Manufacturer hlins Racing Part Number HD 817 Type Code S36DR1 Shock Type Monotube High-Pressure Gas Configuration Twin Rear Shock Set Piston Diameter 36 mm Length 305 mm Stroke 61 mm Spring Rate 32 N/mm Mounted Spring 21180-01 Rebound Adjustment Yes Spring Preload Adjustment Yes Reservoir Internal Serviceable Fully Rebuildable Packaging Pair Fitment Compatible with numerous Harley-Davidson Dyna FXD models (19912017) equipped with 305 mm rear shocks, including: Dyna Super Glide (FXD) Dyna Low Rider (FXDL) Dyna Low Rider EFI (FXDLI) Dyna Low Rider S (FXDLS) Dyna Street Bob (FXDB) Dyna Fat Bob (FXDF) Dyna Super Glide Custom (FXDC) Dyna Super Glide Custom EFI (FXDCI) Dyna Glide Convertible (FXDS-CON) Dyna Switchback (FLD) Always verify your motorcycle's OEM shock length before ordering to ensure correct fitment. Installation The HD 817 is designed as a direct bolt-on replacement using the factory mounting points. Professional installation and suspension setup are recommended to ensure: Proper rider sag Correct spring preload Optimized rebound settings Balanced chassis geometry Maximum suspension performance Proper setup significantly improves handling, comfort, and tire performance. Service and Maintenance Like all premium hlins suspension products, the HD 817 is fully rebuildable and designed for decades of reliable service. Routine maintenance includes replacement of hydraulic oil, seals, and wear components, restoring factory damping performance and extending service life. Regular servicing ensures: Consistent ride quality Maximum hydraulic performance Long-term reliability Protection of your suspension investment Why Choose hlins? For nearly five decades, hlins Racing has led the motorcycle suspension industry through continuous innovation and championship-winning performance in MotoGP, World Superbike, Endurance Racing, and numerous international racing disciplines. The HD 817 STX 36 Twin Rear Shock Set brings that same engineering excellence to the Harley-Davidson Dyna platform, offering riders a substantial improvement in comfort, control, and handling while preserving the motorcycle's timeless styling. Whether you're commuting, touring, or enjoying your favorite backroads, the HD 817 delivers the premium suspension performance that has made hlins the trusted choice of riders around the world.