How Fox DSC Dual Speed Compression Adjusters Work

Fox offers compression adjusters on their 2.0, 2.5, and 3.0 coilovers, smooth body, and internal bypass shocks. Known as the Dual Speed Compression (DSC) adjuster, it features separate knobs for low-speed and high-speed compression tuning. When paired with AccuTune custom valving, Fox DSC adjusters take your off-road suspension to the next level—putting you right in the middle of the adjustment range for easy fine-tuning of both comfort and performance. When it comes to shock tuning, they’ll save you countless hours and deliver significantly better results.

How Do Fox Compression Adjusters Work

Fox compression adjusters feature three distinct flow paths: a low-speed free bleed, a high-speed disk stack, and a rebound check valve. The low-speed compression circuit uses a needle and seat to regulate oil flow through the free bleed pathway, allowing precise control at slower shaft speeds. The high-speed circuit relies on deflective disks to manage oil flow during rapid impacts. This circuit is externally adjustable by increasing preload on the disk stack, giving you control over how the shock responds to big hits. The rebound check valve ensures oil flows back quickly when the shock shaft extends, maintaining consistent performance and ride quality.

How Much Adjustment Do Fox DSC Compression Adjusters Have

Fox Compression Adjusters offer a wide adjustment range that can dramatically change how your vehicle feels—whether you want it to ride like a Cadillac or handle like a race car. The low-speed adjuster has an impressive range, adding between 120% (on solid axle and standard IFS setups) and up to 150% (on light IFS setups) more low-speed damping, depending on the vehicle and tune. The high-speed adjuster can increase high-speed damping by 30% to 60%, also depending on the setup.

These adjusters are especially effective on IFS vehicles, where shocks tend to operate at lower shaft speeds—allowing both the low and high-speed circuits to work together when fully closed. However, since IFS setups also run higher loads, the adjusters represent a smaller percentage of the total damping force, slightly reducing their overall impact.

Fox DSC Really Is Dual Speed Compression Adjustment

The Fox Low Speed Compression Adjuster lets you dial in the perfect balance between ride comfort, handling, and bottoming resistance. It offers a wide usable range, with each of the 9 clicks providing a meaningful change in damping. While some adjustment overlaps into the high-speed range, the majority of the effect is focused on low-speed compression, giving you precise control where it matters most for everyday driving and trail performance.

The dedicated Fox High Speed Compression Adjuster is designed specifically for tuning your suspension over whoops and hard, high-speed impacts. With 11 clicks of adjustment, it offers a wide and effective tuning range—allowing you to fine-tune performance without significantly affecting low-speed compression. This separation gives you precise control over how your vehicle handles big hits, keeping it composed and predictable at speed.

Other Benefits of Compression Adjusters:

Compression adjusters offer a range of lesser-known benefits that significantly enhance shock performance beyond just tunability. Essentially acting as a second damping piston, the adjuster meters oil flow into the reservoir based on piston rod displacement. This design automatically increases both the damping surface area and overall damping force—critical for setups where shocks are working hard, like 2.0s on solid axles or 2.5s on IFS, which can otherwise run out of damping capacity.

Positioned near the reservoir, the compression adjuster also helps transfer heat more effectively into the oil, improving cooling efficiency. Another key advantage is increased consistency: by limiting the volume of oil flowing into the reservoir, the adjuster forces more oil through the main piston, helping prevent cavitation and maintaining damping performance under harsh conditions. These performance gains alone often make adding a compression adjuster a worthwhile upgrade.

Summary

Fox DSC Adjusters deliver real results and are a top choice if you’re adjusting for varying weight, tackling different terrain, or simply aiming for the best ride possible. Due to the way compression adjusters function—and the relatively limited range of high-speed adjustment—these shocks require specialized valving to perform at their best. That’s where AccuTune’s custom equations come in. With AccuTune Valving paired with DSC-equipped Fox shocks, you can fine-tune your suspension for the perfect balance of comfort, control, and performance.

[CLICK] To learn why DSC Adjusters might be for you!