Upgrading Radflo Bypass Shocks Bypasses for Beginners

Bypass Shocks Standard External Bypass Shock

The standard external bypass shock is a triple-bypass. It has two compresson bypass tubes and one rebound bypass tube. Radflo does all their work in-house at their facility in Fountain Valley, California, The tubes are bent, then cut, and machined to the correct height.

The standard external bypass shock is a triple-bypass. It has two compresson bypass tubes

I've been looking around the shock industry for some time, thinking about external bypass shocks. Working for the mag, I feel like I should have tried a set of bypass shocks by now, and I've read/written/seen enough about them to be comfortable to tune them on my own once I had a set. But I've never actually watched a bypass shock be put together in front of me, nor have I ever had firsthand personal experience with them. Part of my lack of bypasses is probably due to the fact that all my trucks are usually broken (you don't need special shocks on something that doesn't move), but the other part that kept me from getting some was the fact that I didn't really think I had any trucks that I could justify putting external bypass shocks on in place of a well-valved standard remote reservoir shock.

One day recently, while I reasoned out in my head why I didn't yet have bypass shocks on something, I realized that the justification of why I didn't have them was the very reason I needed them-I am no whiz at setting up my own shock valving or knowing exactly what valve stack I need. I know if shocks need to be softer or firmer, or if the rebound or compression is too fast or too slow, but I would never try to assemble my own shock valve stack. The absolute beauty of external bypass shocks is that you start with a general valve stack in the shock that is good for your vehicle (actually one that's on the stiff side since the fluid bypass tubes bleed off resistance), and you fine tune everything from a few simple allen wrench-adjustable tubes on the body of the shock. If anything, shock novices almost have more reason to run external bypass shocks than shock experts do (let those experts run the internal bypass shocks!) since it's hard to know what's best until you actually go out and use them.

The bypass adjuster housing is found on the end of the bypass tube. It has an adjustable set screw (an allen screw) that puts more (tightened) or less (loosened) resistance on the bypass popper valve. The looser the bypass tube is, the more fluid it will allow to bypass going through the shock's valve stack.

The bypass adjuster housing is found on the end of the bypass tube. It has an adjustable s

And if you're already at the intermediate shock user's level-using a high-end remote reservoir shock, but not yet up to externally adjustable bypass-then you're halfway there. Since I had already had some smooth-body Radflo shocks (sorry, coilovers will mean you need to run a second shock for bypasses) on a multi-purpose Blazer, I took them back to Radflo to have them modified and upgraded to external bypass units. The cost is around $420 per shock for a three tube bypass (two compression tubes, one rebound tube) setup, and though it basically doubled the price of my 14-inch stroke 2.5 smooth-body shocks (around $400 each), it was much cheaper than going out and buying completely new external bypass shocks (around $780 each). Of course, if the shock needs a rebuild or other parts, the price will go up.

I took some time and drove down to Radflo in Fountain Valley, California, to watch my old smooth-bodies have some bypass tubes added to them. When finished, I grabbed my shocks and headed north to my favorite sand dunes to start tuning them. It was intimidating at first, but as I got more used to tuning them, the truck rode better and better through rough stuff and whoops.

Each bypass tube is built on a jig that makes sure everything is aligned straight. Ryan Evelo is shown here TIG welding the bypass tube together to make sure everything will line up perfectly.

Each bypass tube is built on a jig that makes sure everything is aligned straight. Ryan Ev

Pricing
14-inch stroke 2.5 smooth-body shock	$400 per shock
14-inch stroke 2.5 External triple-bypass shock	$780 per shock
External bypass tube upgrade to standard 2.5 shock	$420 per shock

The main body of the shock is drilled out where each bypass tube meets up with it (shown is just a representative cut piece of a main shock body). Radflo uses a 4-hole web procedure so the wear band has no chance of getting caught like it potentially could if they just used one big drilled hole.
The main body of the shock is drilled out where each bypass tube meets up with it (shown i
There is a standard bypass tube placement on external bypass shocks, but Radflo can put the tubes at different degrees on the body if you request it (if the shock is too close to them frame or something on one side). Evelo placed our tubes so we had a right and left shock, to keep the bypass tubes as far away from the frame as possible.
There is a standard bypass tube placement on external bypass shocks, but Radflo can put th
Once the bypass tubes were put built and laid in the correct position on the already-drilled shock body, Evelo went about TIG welding them on, without the bypass guts in them, of course. After the tubes are welded on the body, it's first honed (in case of any burs) and then sent out for cadmium plating to protect against corrosion. Before the shocks leave, they are pressure tested to make sure there will be absolutely no leaks anywhere.
Once the bypass tubes were put built and laid in the correct position on the already-drill

OnceRadflo was done building the shocks, I grabbed them and ran for my Blazer that, after a 1.5-year hiatus, was almost ready to hit the road again. We quickly got the shocks bolted up and started cranking on the bypass tubes
OnceRadflo was done building the shocks, I grabbed them and ran for my Blazer that, after
The shocks came from Radflo with the tubes preset to a general starting point. The longer compression tube was open all the way, and the shorter compression tube and the rebound tube were open half way. Setting the shocks at the halfway mark is a good starting point, and you can adjust them to allow more or less fluid to bypass in the two compression tubes and single rebound tube. By the way, when upgrading standard shocks to bypass units, Radflo increases the compression valving in the shock since the bypasses relieve it as they are opened up more.
The shocks came from Radflo with the tubes preset to a general starting point. The longer
I admit that I still haven't gotten my shocks perfectly dialed in yet, but the big K5 Blazer rolls through whoops so much better already.
I admit that I still haven't gotten my shocks perfectly dialed in yet, but the big K5 Blaz