Radflo 3.0 Bypass Shock w/ Piggyback Reservoir – 4-Tube, 1” Shaft
7BP-403-00
The Radflo 3.0 4-Tube Bypass Shock with Piggyback Reservoir is built for high-load off-road suspension systems that need maximum damping capacity and external tuning control. With a 3.0" shock body, heavy-duty 1" shaft, four external bypass tubes, and an integrated piggyback reservoir, it is designed for rock bouncers, Ultra4 cars, desert race vehicles, competition crawlers, and other high-performance off-road builds.
Four externally adjustable bypass tubes create multiple damping zones throughout the shock travel, giving builders greater control over chassis movement, traction, impact absorption, and bottom-out resistance. The large 3.0" body provides increased oil volume and damping capacity for heavier vehicles, larger tires, long-travel suspension, and sustained aggressive driving where shock control and heat management are critical.
Includes:
- (1) Radflo 3.0 4-Tube Bypass Shock
- Piggyback Reservoir
- Universal Spherical Bearings & Mounting Hardware
Notes:
- Sold individually
- Universal shock for custom suspension applications
Availability: As the #1 stocking warehouse for Radflo Performance Shocks, we maintain one of the largest inventories of Radflo shocks and springs in the industry. While many popular configurations are available for immediate shipment, certain shock configurations, custom valving packages, and special-order suspension components may require 4–6 weeks for production and delivery.
Need parts quickly? Call us for current inventory availability and help selecting the right shocks, springs, or suspension package for your build.
Specifications
| Specification | Details |
|---|---|
| Manufacturer | Radflo Suspension Technology |
| Shock Type | 4-Tube External Bypass with Piggyback Reservoir |
| Body Diameter | 3.0" |
| Travel Options | 14", 16" |
| Shaft Diameter | 1.0" |
| Bypass Tubes | 4 External Bypass Tubes |
| Reservoir | Piggyback Reservoir |
| Body Material | SSID Alloy Steel Tube |
| Body Finish | Clear Cadmium Plated |
| Shaft Material | Nitro Steel® |
| Shaft Finish | Mirror Polished |
| Piston | Radflo Aluminum FreeFlo® Racing Piston |
| Rod Guide | CNC-Machined Bronze with PTFE Coating |
| Seal System | Quad-Ring® & Lip Seal Combination |
| Body Caps & Eyelets | CNC-Machined 6061 Aluminum |
| Body Cap Finish | Black Anodized |
| Bearings | 5/8" Universal Spherical Bearings |
| Valving Type | Velocity-Sensitive Deflective Disc |
| Valving Adjustment | Externally Adjustable Bypass Zones |
| Valving Tuning | Consumer or Factory Tunable |
| Shock Oil | Radflo High-Temperature Foam-Resistant Suspension Fluid |
| Pressurization | Nitrogen Gas |
| Nitrogen Pressure | Starting at 200 PSI, Application Dependent |
| Serviceability | Rebuildable & Serviceable |
| Quantity | Sold Individually |
Fitment
Universal external bypass shock for custom front or rear suspension applications including:
- Rock bouncers
- Ultra4 race cars
- Desert race vehicles
- Competition rock crawlers
- Prerunners
- Long-travel off-road suspension systems
- Custom tube chassis vehicles
- High-horsepower off-road builds
Fitment Notes:
- Select shock travel based on available suspension travel and mounting geometry.
- External bypass tubes require additional chassis and suspension clearance compared with a standard smooth body shock.
- Verify compressed length, extended length, mounting width, piggyback reservoir clearance, and bypass tube clearance before ordering.
- Final valving and bypass adjustment should be matched to vehicle weight, suspension geometry, spring rate, driving style, and intended terrain.
FAQ
What does a 4-tube bypass shock do?
A 4-tube bypass shock uses external fluid passages to create different damping zones throughout the shock travel. These zones allow the suspension to be tuned for ride control, chassis movement, impact absorption, and bottom-out resistance at different points in the stroke.
What is the difference between a 3-tube and 4-tube bypass shock?
The additional bypass circuit provides another level of control over how fluid moves through the shock at different piston positions. A 4-tube configuration gives the suspension tuner greater flexibility when establishing compression and rebound characteristics throughout the travel.
Why choose a 3.0 bypass shock instead of a 2.5 bypass shock?
A 3.0 shock body provides greater oil volume and damping capacity than a 2.5 shock. That additional capacity becomes increasingly valuable with heavier vehicles, larger tires, longer suspension travel, higher speeds, and sustained aggressive use where heat management and damping consistency are critical.
What is the advantage of a piggyback reservoir?
A piggyback reservoir increases fluid and nitrogen capacity while keeping the reservoir attached directly to the shock body. This eliminates the remote reservoir hose and creates a self-contained package where chassis clearance allows it.
What vehicles are best suited for a Radflo 3.0 4-Tube Bypass Shock?
This shock is best suited for high-performance builds that generate significant suspension loads, including rock bouncers, Ultra4 cars, desert race vehicles, competition crawlers, prerunners, and custom long-travel off-road vehicles.
Are Radflo 3.0 4-Tube Bypass Shocks rebuildable and tunable?
Yes. Radflo bypass shocks are rebuildable and serviceable, and the shock can be tuned as the vehicle setup evolves. The external bypass system also allows damping characteristics to be adjusted without completely relying on internal valving changes.
