The Radflo 2.5 DRT Internal Bypass Coilover with Remote Reservoir and Dual Compression & Rebound Adjusters represents the highest level of suspension tuning available in the DRT lineup. Combining Radflo's proprietary RST Dynamic Ride Technology, position-sensitive internal bypass damping, remote reservoir performance, and fully adjustable high-speed and low-speed compression and rebound controls, this shock is engineered for serious off-road enthusiasts, racers, and builders who demand maximum control.

Unlike conventional coilovers that generate damping exclusively through the piston and shim stack, DRT Internal Bypass technology creates multiple damping zones throughout the suspension travel. This allows the shock to remain exceptionally compliant over chatter, washboards, roots, and rocks while progressively increasing damping force deeper in the stroke to control large impacts, whoops, jumps, and bottom-out events. The result is a suspension that feels plush during normal driving yet remains controlled and confidence-inspiring when pushed hard through aggressive terrain.

Each shock is custom built and tuned to your specific application, with independent tuning available for:

• Main Piston Compression Valving
• Main Piston Rebound Valving
• Internal Bypass Compression Zones
• Internal Bypass Rebound Zones
• High-Speed Compression Adjustment
• Low-Speed Compression Adjustment
• High-Speed Rebound Adjustment
• Low-Speed Rebound Adjustment

This advanced tuning capability allows builders and racers to fine-tune suspension performance for rock crawling, Ultra4 competition, desert racing, prerunning, overlanding, trail riding, and custom off-road applications.

Includes:

• (1) Radflo 2.5 DRT Internal Bypass Coilover Shock
• Remote Reservoir
• Compression Adjusters (HSC & LSC)
• Rebound Adjusters (HSR & LSR)
• Universal Spherical Bearings & Mounting Hardware
• JIC/ORB Reusable Hose Fittings

Springs Sold Separately
Sold Individually

Specifications

• Brand: Radflo Suspension Technology
• Series: DRT Internal Bypass
• Shock Type: Internal Bypass Coilover
• Reservoir Type: Remote Reservoir
• Body Diameter: 2.5"
• Travel Lengths: 8", 10", 12", 14", 16", 18"
• Shaft Diameter: 7/8"
• Shaft Material: 17-4PH Stainless Steel
• Adjustability: High-Speed Compression, Low-Speed Compression, High-Speed Rebound, Low-Speed Rebound
• Internal Bypass: Proprietary RST Dynamic Ride Technology
• Main Piston: Custom Compression & Rebound Valving
• Internal Bypass Tuning: Custom Compression & Rebound Zones
• Piston: 2.0" 6061-T6 Billet Aluminum RST HiFlo Race Piston
• Piston Finish: Type II Hard Anodized
• Body Material: SSID Alloy Steel
• Body Finish: Zinc Plated with Clear Coat
• Rod Guide: Machined Bronze with PTFE Coating
• Bearings: FK Heat-Treated Steel Spherical Bearings, PTFE Lined
• Body Caps: CNC Machined 6061 Aluminum
• Body Cap Finish: Black Anodized
• Oil: Radflo High-Temp Foam Resistant Suspension Fluid
• Pressurization: Nitrogen Gas
• Serviceability: Consumer or Factory Serviceable
• Tuning: Consumer or Factory Tunable
• Country of Origin: USA

Fitment

Universal fitment for custom suspension systems including:

Verify mounting dimensions, spring requirements, travel length, and suspension geometry prior to ordering.

Tech Insight

What is the difference between internal bypass and external bypass shocks?

External bypass shocks use visible bypass tubes mounted outside the shock body.

Internal bypass shocks create the same damping zones inside the shock body.

Internal Bypass Advantages:

• Easier packaging
• Cleaner installation
• Less maintenance
• Better fitment in tight chassis

External Bypass Advantages:

• Maximum external tuning
• Greater adjustability for race teams

For most enthusiasts and racers, DRT Internal Bypass delivers exceptional performance without the packaging challenges of external bypass shocks.

What do High-Speed Compression (HSC) adjusters do?

High-Speed Compression affects how the shock responds to:

• Rocks
• Whoops
• G-outs
• Jump landings
• Square-edge impacts

Increasing HSC creates more impact resistance and bottom-out control.

What do Low-Speed Compression (LSC) adjusters do?

Low-Speed Compression affects:

• Body roll
• Brake dive
• Acceleration squat
• Steering response

Increasing LSC creates a more controlled and stable chassis feel.

What do High-Speed Rebound (HSR) adjusters do?

High-Speed Rebound controls how quickly the suspension extends after larger impacts.

Adjusting HSR helps:

• Control bucking
• Improve stability
• Manage suspension recovery after hard hits

What do Low-Speed Rebound (LSR) adjusters do?

Low-Speed Rebound affects:

• Vehicle balance
• Weight transfer
• Chassis stability
• Cornering behavior

Fine-tuning LSR allows drivers to dial in handling characteristics for specific terrain.

How does the DRT Ride Zone work?

The Ride Zone is located near normal ride height.

In this area, proprietary bypass circuits allow oil to flow around the piston, significantly reducing harshness and improving traction over rough terrain.

What is the DRT Build Zone?

As the shock moves deeper into travel, internal bypass channels progressively close.

This increases damping force to:

• Prevent bottoming
• Improve body control
• Increase suspension support

Is this shock good for rock crawling?

Yes. DRT technology dramatically improves traction and ride comfort over rocks while maintaining control during large compression events.

Is this shock good for desert racing?

Absolutely. DRT shocks excel in high-speed terrain by reducing chatter and increasing stability through whoops, washboards, and rough desert conditions.

Can I revalve and tune these shocks later?

Yes. The DRT Series is fully rebuildable, serviceable, and tunable. Compression, rebound, and internal bypass characteristics can all be modified for changing vehicle setups and driving styles.