444 series shocks: Comes with FST (Frequency Sensing Technology) which dynamically adjusts damping; according to road surface. Top mount threaded hand adjustable preload. Note: Optionally available is 704545 for an optional QPS (Quick Preload System) adjustment kit. It replaces the stock upper shock caps of all 444 & 944 series Touring shocks; allowing quick preload adjustment without removing the saddlebags. What are Progressive Suspension''s ''Heavy Duty'' shocks? If you are a lightweight rider with a lightweight passenger; STD Duty is probably your best choice; heavy duty shocks will give you a harsh ride. For Big Guys & Gals with a lot of baggage; Heavy Duty springs are the way to go. Heavy Duty is not better; it''s different.Heavy Duty shocks or springs are recommended to be used on motorcycles that are operated at or near the manufacturers maximum load rating over 50% of the time.

RAP adjustable. 422 series - Better. Two inches; standard to 2" lower; of ride height adjustment and adjustable preload. High pressure gas system in a dual coil shock system. The shocks include a new fill valve to replace the stock one. Also available in the RAP (Remote Adjustable Preload) series; which comes with the added convenience of a Remote Adjustable Preload; located behind the left passenger peg; for easier accessible adjustments. What are Progressive Suspension''s ''Heavy Duty'' shocks? If you are a lightweight rider with a lightweight passenger; STD Duty is probably your best choice; heavy duty shocks will give you a harsh ride. For Big Guys & Gals with a lot of baggage; Heavy Duty springs are the way to go. Heavy Duty is not better; it''s different.Heavy Duty shocks or springs are recommended to be used on motorcycles that are operated at or near the manufacturers maximum load rating over 50% of the time.

990 Sport series - Best. With bushing. Based on the 970 series but designed towards aggressive sport/race inspired riding. No other shock offers this much tuning adjustability. Features include a linear rate coil spring; a 0.4" adjustable eyelet height and adjustable threaded preload; a piggyback reservoir (remote for Touring) has a knob to adjust both rebound and high & low speeds compression damping. Featured in a lightweight aluminum body the high-pressure monotube with deflective disc damping routed through two unique circuits delivers a consistent feel through the damper stroke for improved performance and stability. A new and improved engineered jounce bumper features a captured design to help smooth and control bottoming out. Each shock is hand-built & dyno tested to deliver real world performance.What are Progressive Suspension''s ''STD Duty'' vs ''Heavy Duty'' shocks? If you are a lightweight rider with a lightweight passenger; STD Duty is probably your best choice; heavy duty shocks will give you a harsh ride. For Big Guys & Gals with a lot of baggage; Heavy Duty springs are the way to go. Heavy Duty is not better; it''s different.Heavy Duty shocks or springs are recommended to be used on motorcycles that are operated at or near the manufacturers maximum load rating over 50% of the time. Note: Remote reservoir strut mounts. For a different; wild & aggressive look see 941797 Progressive Suspension''s (alternative style) remote rear reservoir fender strut cover mount

444 series shocks: Comes with FST (Frequency Sensing Technology) which dynamically adjusts damping; according to road surface. Top mount threaded hand adjustable preload. Note: Optionally available is 704545 for an optional QPS (Quick Preload System) adjustment kit. It replaces the stock upper shock caps of all 444 & 944 series Touring shocks; allowing quick preload adjustment without removing the saddlebags. What are Progressive Suspension''s ''Heavy Duty'' shocks? If you are a lightweight rider with a lightweight passenger; STD Duty is probably your best choice; heavy duty shocks will give you a harsh ride. For Big Guys & Gals with a lot of baggage; Heavy Duty springs are the way to go. Heavy Duty is not better; it''s different.Heavy Duty shocks or springs are recommended to be used on motorcycles that are operated at or near the manufacturers maximum load rating over 50% of the time.