Shocks, Springs & Custom Tuning
In conjunction with Radflo Suspension Technology, 4Wheel Underground has its own custom built shocks. Known only as the 4WU Spec, the recipe we've cooked up is highly "CLASSIFIED".

The end result is a soft ride over small high speed sections, larger hits are soaked up with unbelievable control and yet the vehicle still responds crisp and nimble with little body lean for street driving. If you think a Coil-Overed rock buggy suspension has to be a slinky sloppy mess, then you've never experienced what Tuned Coil-Over can truly do.

The next time you see us on the trail, ask for a ride and let us show you what our experience can do for your ride.

Experience what a Coil-Over should be.

Please note that coilovers and shock orders can take 2-4 weeks to ship. All orders are custom. We tune each shock and spring to your needs. All springs come in three color choices. Black, Silver and Orange. All this takes time to meet your needs and desires. Please order in advance for your build so you are not delayed. Thank you.

Radflo Coil-Over and Smooth Body Shock Absorbers

         Shaft                Travel        Ext. Comp.  
2.0” Emulsion7/8”   12”31.50”19.53" 
2.0” Emulsion7/8”   14”35.43"21.50"
2.0” Emulsion7/8”   16”39.76”23.78”

2.0” Remote Reservoir   7/8”          12”        31.50”        19.53”
2.0” Remote Reservoir   7/8”          14”        35.43"        21.50"
2.0” Remote Reservoir   7/8”          16”        39.76”        23.78"  

90* Fitting from shock body.    $30 per shock
Another reason to go Radflo
NitroSteel® bars simply outperform and outlast hard chrome plated bars. With superior corrosion resistance, better lubrication retention, and improved wear resistance, they are the perfect cost effective alternative to chrome bars.

NitroSteel® Process
NitroSteel® carbon and alloy steel bars and tubes are surface hardened by the exclusive NitroSteel® process. This is an atmospheric furnace treatment developed and patented in the early 1980's. It combines the high surface hardness and corrosion resistance of nitriding with the additional corrosion resistance gained by oxidation. NitroSteel® is environmentally friendly and a vastly superior performing alternative to hard chrome plate.

The manufacturing process begins with the cleaning and super-polishing of ground and polished steel bars or honed and polished steel tubes. In preparation for treatment, material is polished to a surface roughness of 6 to 10 Ra, cleaned, fixtured vertically, and lowered into an electrically heated pit furnace.

The furnace sequence entails nitrocarburizing the steel lengths at temperatures up to 1150ºF in an ammonia atmosphere with exothermic gases. The steel's surface is converted to an epsilon iron nitride to a depth of 0.001". Atmospheric oxidizing is utilized to produce a black corrosion resistant surface film of iron oxide. The process generates a thin (0.001") uniform and extremely hard (64 to 71 Rc) iron nitride layer infused with a film of iron oxide. Beneath the iron nitride layer is a nitrogen-enriched hardened diffusion zone. The diffusion zone functions as a light hardened case with a hardness gradient ranging from the mid-50's Rc just below the iron nitride layer to approximately 40 Rc at 0.015" depth.

Why haven’t the other guys done this.


Raflo Coilovers with Pac Springs. Daul Rate System
per Pair

16" Reservoir ($1145.00)
16" Emulsion ($945.00)

Add 90* Fittings to shock body ($60) pair
Raflo Coilovers with Pac Springs. Dual Rate System
per Pair

14" Reservoir ($1125.00)
14" Emulsion ($925.00)

Add 90* Fittings to shock body ($60) pair
Coilover Packages
Raflo Coilovers with Pac Springs. Dual Rate System
per Pair

12" Reservoir ($1115.00)
12" Emulsion ($915.00)

Add 90* Fittings to shock body ($60) pair
Resi's
Emulsion
Radflo Smooth Body Shock Absorbers

***Free shipping on all smooth body shocks until the end of May 2015***

12" 2.0" Emulsion 5/8" Shaft$ 190 ea.
12" 2.0" Remote Reservoir 5/8" Shaft   $ 270 ea.
12" 2.0" Emulsion 7/8" Shaft$ 255 ea.
12" 2.0" Remote Reservoir 7/8" Shaft   $ 345 ea.

14" 2.0" Emulsion 7/8" Shaft$ 265 ea.
14" 2.0" Remote Reservoir 7/8" Shaft   $ 355 ea.