6 Best Adjustable Spacers For Custom Suspension Tuning

Mastering suspension performance often comes down to the subtle art of volume management inside your fork. Proper tuning prevents harsh bottom-outs while ensuring you utilize the full range of your travel on technical descents. Understanding how these small, plastic, or foam components alter your ride quality is the key to transforming a stock setup into a personalized machine.

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MRP Ramp Control: Best On-The-Fly Adjustment

The MRP Ramp Control cartridge replaces standard volume spacers with a mechanical valve that offers high-speed compression damping adjustments. This allows for mid-ride tweaks without the need for tools or fork disassembly. It is the ideal upgrade for riders who traverse varied terrain, from flowy singletrack to high-speed, rocky chunder, all in a single outing.

While the upfront cost is higher than a simple plastic token, the versatility provided justifies the investment for performance-minded riders. The ability to increase or decrease bottom-out resistance while at the trailhead makes this an indispensable tool for experimental tuning. For those tired of guessing their spacer needs before leaving the garage, this is the definitive solution.

RockShox Bottomless Tokens: Best Value Option

RockShox Bottomless Tokens are the industry standard for simplicity and cost-effectiveness. These threaded plastic discs screw directly into the top cap of the air spring, allowing for incremental changes to the air chamber volume. They are the perfect entry point for riders looking to understand how progression affects their bike’s handling.

Because they are inexpensive and widely available, they encourage experimentation without the fear of a costly mistake. If a ride feels too linear or prone to harsh bottoming, adding a single token can make a profound difference in mid-stroke support. For the vast majority of riders, this system provides all the tuning capability necessary to dial in a high-performing suspension setup.

Fox Float Volume Spacers: Best for Fox Forks

Fox utilizes a proprietary clip-on spacer system specifically designed for the unique volume of their FLOAT air springs. These spacers snap into place easily, ensuring a secure fit that will not migrate or rattle inside the stanchion. They are engineered to work in perfect harmony with the specific air spring curves inherent to the Fox product line.

Precision is the hallmark of this system, providing a consistent feel that mirrors the design intent of the fork’s engineers. Riders who favor Fox suspension should stick to these dedicated components rather than attempting third-party modifications. They are a reliable, “set it and forget it” solution for those who want their suspension to perform exactly as the manufacturer intended.

Vorsprung Secus: Top Premium Suspension Tuning

The Vorsprung Secus is an external air spring upgrade that mimics a larger negative air spring volume to provide a “coil-like” sensitivity at the start of the stroke. It fundamentally changes how the fork behaves by decoupling initial compliance from end-stroke progression. This is the top-tier choice for riders seeking ultimate traction and a supple feel across small, repetitive bumps.

Though installation requires more technical mechanical skill, the benefits for aggressive riders are unmatched. It allows the fork to track small trail chatter while remaining highly supportive during heavy hits. For those who feel their air fork lacks the sensitivity of a coil shock, the Secus is the ultimate performance bridge.

Formula Neopos: Best Progressive Feel Spacers

Formula’s Neopos spacers are crafted from a compressible, closed-cell foam material rather than rigid plastic. As the fork compresses and pressure builds, the foam itself compresses, creating a dynamic, progressive ramp-up. This material provides a more natural, predictable feel throughout the travel, avoiding the “wall” sensation that can sometimes occur with traditional solid spacers.

This product is highly recommended for riders who find that plastic spacers make their fork feel too abrupt at the end of the stroke. The foam allows for a smoother transition as the fork reaches its limit, increasing rider confidence on large drops or jump lines. If a predictable, bottomless sensation is the goal, Neopos offers a unique and effective solution.

DVO Suspension Volume Spacers: Best Precision

DVO utilizes a specialized volume adjustment system that focuses on high-precision internal volume control. Their spacers are designed to be stackable and secure, ensuring that the volume remains constant even under extreme heat generated by long, descending efforts. This consistency is critical for racers or those frequently tackling long-duration alpine descents.

The design reflects a deep understanding of thermal expansion and its impact on air pressure. For those who value a consistent feel from the first turn to the bottom of a 2,000-foot descent, DVO offers the necessary stability. This is a choice for the rider who prioritizes mechanical reliability and consistent performance over all else.

How to Match Volume Spacers to Your Trail Type

• Flow Trails: Favor fewer spacers to allow the fork to sit slightly deeper in its travel for better cornering grip and pop.
• Rocky, Technical Terrain: Increase the number of spacers to provide more ramp-up support, keeping the front end high during consecutive, square-edge hits.
• Steep, Natural Descents: Utilize a moderate to high spacer count to prevent the fork from diving under heavy braking, which helps maintain steering geometry.
• Jumps and Drops: Maximum spacers are often preferred to provide a firm, progressive platform that resists harsh bottoming on flat landings.

Understanding Air Spring Curves and Bottom Out

Air springs are inherently progressive, meaning they get harder to compress the deeper the fork travels. Volume spacers amplify this effect by reducing the size of the air chamber, which causes pressure to ramp up more quickly. Understanding this curve helps riders identify why a fork feels “mushy” in the mid-stroke or “harsh” at the end.

A common misconception is that adding pressure alone will solve bottom-out issues. While more pressure does help, it also ruins small-bump sensitivity and makes the fork feel overly stiff off the top. Spacers allow for a lower base pressure while still providing the necessary ramp-up to prevent bottoming out.

Step-by-Step Guide for Safe Spacer Installation

1. Release Pressure: Always remove every bit of air from the fork before loosening the top cap to prevent the assembly from ejecting unexpectedly.
2. Clean the Area: Wipe away any dirt or grit from the fork crown before opening the air chamber to ensure no debris enters the sensitive internal seals.
3. Use Proper Tools: Utilize the correct size socket to prevent rounding the top cap, which is often made of soft aluminum.
4. Lubricate O-rings: Ensure the spacer interface or O-rings are lightly coated with suspension grease to maintain an airtight seal upon reassembly.
5. Torque Correctly: Reinstall the top cap to the manufacturer’s specified torque to avoid stripping threads or cracking the air spring assembly.

Diagnosing Trail Feedback and Adjusting Spacers

If the fork feels like it is blowing through its travel on moderate hits, start by adding one token or spacer. Conversely, if the fork is physically impossible to compress to its full length even on the biggest hits of the ride, remove a spacer. The goal is to reach full travel only on the largest impacts of the trail, leaving a small margin of safety.

Take notes on how the bike feels after each change, as small adjustments can have large consequences on handling. Do not make multiple changes at once, such as adjusting air pressure and volume simultaneously. Isolating variables allows for a calculated approach to tuning, ensuring every change brings the bike closer to a perfectly balanced setup.

Fine-tuning your air volume is one of the most rewarding mechanical tasks you can perform to improve your riding experience. By dedicating time to understand your equipment, you remove the limitations of stock settings and unlock the true potential of your bike. Grab your tools, head to the trailhead, and enjoy the confidence that comes with a perfectly dialed ride.