Shock Tech: IFP Shocks, Remote Reservoir Shocks and Emulsion Shocks
August 18, 2020
Emulsion Shock
- Oil and nitrogen are combined inside a single main shock body with no external reservoir.
- This design—known as an emulsion shock—leads to inconsistent damping because the nitrogen mixes with the shock oil.
- The limited space for nitrogen requires significantly higher internal pressures.
- Higher pressure increases friction, generates more heat, and leads to reduced ride quality.
- Unlike reservoir shocks where only oil flows through the valving, emulsion shocks force a mix of oil and nitrogen through, reducing damping precision.
- The elevated pressure also causes seals to compress more aggressively, which accelerates wear.
- Emulsion shocks are a budget-friendly option best suited for basic use, where performance isn’t a top priority.
- Due to these limitations, Fox has discontinued their 2.0 smoothie emulsion shocks in favor of higher-performance designs.
Examples of Emulsion Shocks available for purchase:
(IFP) Internal Floating Piston Shock
- Oil and nitrogen are housed in a single shock body but kept separate by an internal floating piston (IFP).
- The compact design leaves limited space for nitrogen, often requiring higher internal pressures.
- High pressure increases seal friction, leading to quicker wear and a harsher ride.
- The IFP takes up internal space, which means less overall shock travel compared to reservoir-style shocks.
- The nitrogen fill port is often difficult to access, making servicing or refilling a challenge.
- Most 2.0 IFP shocks are non-user-serviceable and must be rebuilt by the manufacturer—if at all—making them expensive or impractical to maintain.
- Best suited for mostly street-driven vehicles that rarely see aggressive off-road use.
- Commonly considered “throwaway” shocks once worn out due to limited serviceability and lower performance potential.
Examples of IFP Shocks available for purchase:
Remote Reservoir Shock
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Oil and nitrogen are separated by a floating piston inside the reservoir.
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The main shock body is dedicated to oil, while the secondary reservoir holds mostly nitrogen and some oil.
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Nitrogen in the reservoir maintains stable pressure on the oil in the main shock body.
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This nitrogen pressure aids tuning by forcing oil through the main piston valving.
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Stable pressures reduce seal wear, helping shocks last longer than IFP and emulsion designs.
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Reservoir shocks come in various sizes and lengths: 2.0, 2.5, 3.0, and 4.0 inches.
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Piggyback shocks are also considered a type of remote reservoir shock.
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Many reservoir shocks offer options to add compression adjusters like Fox DSC or King Mid-Speed adjuster.
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Most Fox and King remote reservoir shocks are fully serviceable and tunable.
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Remote reservoir shocks are ideal for vehicles seeking improved performance and comfort, offering endless tuning options for the best ride quality.
Examples of Remote Reservoir Shocks available for purchase: