6 Best Suspension Shims For Fine-Tuning Damping On Trails

Nothing ruins a long-awaited ride quite like a shock that feels harsh over chatter or wallows in deep corners. Fine-tuning the internal damping of your suspension transforms a generic ride into a precision machine tailored exactly to the trail. Mastering these micro-adjustments allows you to extract every ounce of performance from your bike regardless of the terrain.

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Fox Racing Shox Tuning Kit: Best Overall

Fox Racing Shox Tuning Kits provide the benchmark for consistency and material quality in the industry. These kits offer a massive range of shim diameters and thicknesses, making them the go-to choice for riders who demand factory-level performance. When looking for a reliable starting point for any revalve project, these kits are the gold standard.

The primary strength of the Fox ecosystem lies in the documentation and support provided for their specific damping circuits. Using genuine shims ensures that the oil flow characteristics match the intended design of the damper, preventing cavitation or unwanted harshness. For riders already running Fox Factory or Performance suspension, this is the most logical and effective path.

If your goal is to match the tune of a professional racer or simply restore the plush feeling of a well-loved fork, look no further. The completeness of the kit removes the guesswork of hunting down individual parts. For anyone seeking a balanced, predictable suspension feel, this kit is the definitive choice.

RockShox Tuning Shims: Best Value Option

RockShox tuning kits prioritize accessibility and simplicity, making them an excellent entry point for home mechanics. These shims are priced aggressively, allowing riders to experiment with different “stacks”—the layered arrangement of shims—without breaking the bank. It is the perfect ecosystem for the tinkerer who wants to learn how fluid dynamics actually affect trail feedback.

These kits are often found in comprehensive sets that cover various weight ranges and riding styles, from XC racing to bike park laps. While they may not feature the same exotic material coatings as premium boutique options, they provide an incredibly high performance-to-cost ratio. You will find that these shims perform admirably in the vast majority of trail conditions.

Because they are widely available and affordable, riders should feel empowered to test multiple configurations to find their “sweet spot.” This is the ideal option for the rider who wants to iterate quickly on their setup without a massive financial investment. If value and accessibility are the primary concerns, these shims are the perfect fit.

Race Tech Gold Valve Shims: Top Precision

Race Tech has carved out a reputation for providing the highest level of precision in the suspension aftermarket. Their Gold Valve shims are engineered to minimize flow turbulence, resulting in a damping feel that is remarkably consistent through the entire stroke. For those who feel that standard shim stacks lack the mid-stroke support needed for aggressive riding, this is a top-tier upgrade.

The engineering behind these shims focuses on “digressive” and “progressive” valving strategies that help the shock react differently to slow-speed impacts versus high-speed hits. This level of technical sophistication allows for a ride that is supple over roots but firm enough to resist bottoming out on drops. It is the preferred choice for riders who are frustrated by the limitations of stock valving.

Investing in Race Tech means committing to a more methodical approach to suspension tuning. The results, however, are undeniable for those who prioritize handling precision above all else. If you are chasing a specific, high-performance ride characteristic that stock components cannot provide, these are worth every penny.

Push Industries Shim Kit: Best for Enduro

Push Industries builds their shims with the demands of modern enduro racing in mind, where heavy loads and sustained heat are the status quo. These shims are designed to maintain their shape and damping characteristics even after long, punishing descents. If your local trails involve high-speed rock gardens or sustained vertical descent, the durability of these components is a significant advantage.

The design philosophy behind Push shims emphasizes a “supportive” feel that keeps the bike high in its travel through berms and compression zones. This prevents the “packing down” sensation where the suspension feels sluggish during repetitive hits. They are crafted for riders who prioritize control and predictability in unpredictable, high-stakes environments.

While they carry a premium price tag, the longevity and consistent performance in demanding conditions make them an essential upgrade for enduro enthusiasts. Choosing Push is a commitment to a setup that handles abuse without fading. If you regularly ride terrain that pushes your current suspension to its boiling point, this is the upgrade to make.

Ohlins MTB Shock Shims: Premium Upgrades

Ohlins brings a heritage of motorsport dominance into the world of mountain biking, and their shim kits reflect that pedigree. These components are precision-machined to exacting tolerances, ensuring that oil flow is controlled with surgical accuracy. For the rider who treats their bike like a high-performance vehicle, Ohlins offers an unmatched level of refinement.

Using these shims requires a deeper understanding of suspension geometry, as their impact on damping is both significant and subtle. They are best suited for riders who already have a baseline understanding of how their suspension should behave and are looking for that last 5% of performance. The premium cost reflects the engineering effort involved in creating such a precise damping environment.

These are not for the casual tinkerer; they are professional-grade tools for those serious about tuning perfection. When paired with Ohlins dampers, the result is a level of ride quality that feels distinctively stable and composed. If you settle for nothing less than the pinnacle of suspension technology, these shims are the obvious choice.

Cane Creek Tuning Shims: Most Customizable

Cane Creek is famous for its “Double Barrel” technology, and their shim kits offer immense flexibility for riders who love to dive deep into setup. Their shims are designed to work within highly adjustable damping circuits, allowing for a near-infinite range of customization. This is the ultimate playground for the rider who enjoys adjusting high-speed compression and low-speed rebound independently.

The versatility offered by these kits means you can tune your bike to be drastically different for a smooth flow trail versus a jagged, technical descent. It is a system built for those who understand how oil displacement and shim thickness interact to change the bike’s personality. If you find standard damping adjustments limiting, the granular control provided here will be a revelation.

Be prepared to spend time on the trail testing and documenting your changes. This is not a “set it and forget it” solution; it is a system for the rider who treats suspension tuning as part of the sport itself. If you love the process of optimization, Cane Creek provides the most robust toolkit available.

How to Choose Shims for Your Riding Style

Selecting the right shims begins with identifying your primary riding terrain and your individual weight. Heavier riders or those who ride aggressive, steep terrain require stiffer shim stacks to provide the necessary support to prevent harsh bottom-outs. Conversely, lighter riders or those who prioritize grip on technical, slow-speed terrain will benefit from a thinner, more compliant shim configuration.

Consider whether you prefer a “planted” feel that tracks every contour of the ground, or a “poppy” feel that favors jumps and side-hits. A stack that is too stiff will cause the bike to deflect off obstacles, while one that is too soft will make the bike feel unresponsive. The goal is to strike a balance where the suspension stays active without blowing through its travel.

Always start by documenting your current “base tune” before making any modifications. Changing only one variable at a time—such as a single shim thickness—is critical to understanding how the change affects the trail. Avoid the temptation to change everything at once, or you will lose track of what actually improved the ride.

Understanding Compression vs Rebound Damping

Compression damping controls how quickly the suspension compresses when hitting an object, while rebound damping controls how quickly it returns to its extended state. Compression needs to be firm enough to resist pedaling bob and heavy impacts but soft enough to absorb small vibrations. If your front end feels “harsh” on small roots, you likely have too much compression damping.

Rebound is equally vital; it determines how much “energy” the bike returns to you after a compression. If the rebound is too fast, the bike will feel like a pogo stick and lose traction over repeated bumps. If the rebound is too slow, the suspension will “pack down,” failing to recover in time for the next obstacle.

The interplay between these two is the secret to a balanced bike. A well-tuned setup should feel stable and composed, returning to full extension exactly when needed without bucking the rider. Use your shims to fine-tune the high-speed circuits to handle big hits, while keeping low-speed circuits tuned for rider-input efficiency.

Essential Tools for Home Suspension Tuning

Properly working on suspension requires a set of specialized tools to avoid damaging seals and delicate valve shims. A high-quality internal snap-ring plier set is non-negotiable, as most dampers are held together by these small, finicky clips. You will also need a precise torque wrench, as over-tightening the damper bolt can crush the shim stack and ruin the valving.

A vacuum bleeder or a high-quality hand pump is necessary to remove trapped air from the system once you have finished revalving. Even a tiny air bubble can cause “dead spots” in the damping, making the suspension feel unpredictable and inconsistent. Finally, invest in a dedicated set of suspension oil graduated cylinders to ensure the exact oil volume is replaced.

Maintain a clean, organized workspace to ensure no grit or debris enters the oil. Suspension components are extremely sensitive to contaminants, and even a microscopic piece of dirt can cause a valve to stick. Having the right tools won’t just make the job easier—it ensures the safety and longevity of your gear.

When to Revalve Instead of Just Reshimming

Reshimming is a surgical process of tweaking the existing damping characteristics, whereas a full revalve often involves changing the piston or the overall shim architecture. You should consider a full revalve when you reach the limits of your current shim stack’s capability. If you find yourself consistently at the max or min of your clicker adjustments with no satisfaction, it is time for a revalve.

Additionally, if you have significantly changed your bike’s intended use—such as moving from cross-country riding to lift-accessed downhill—a revalve is often necessary. The stock valving is designed for a specific leverage curve and rider weight; once you stray too far from that design, the stock setup becomes a liability. A revalve resets the performance baseline to suit your current reality.

Do not fear the revalve; it is often the most cost-effective way to make an older bike feel brand new. It allows you to tailor your equipment to your evolving skills and changing local trail conditions. When you find that you are fighting the bike more than the terrain, it is time to look at the internals.

Properly tuned suspension is the bridge between a rider and the trail, turning obstacles into opportunities for speed and flow. By taking the time to understand and adjust your damping, you ensure that your gear works for you rather than against you. Grab your tools, head to the trailhead, and enjoy the transformative power of a perfectly dialed ride.