A detailed blog about dual-flow valves, Öhlins Road & Track, and some extra advice about counting your clicks, bending your needles, and damaged orifices.
What TF is DFV?
DFV, or Dual Flow Valve technology, is Öhlins' signature innovation that sets its Road & Track (R&T) coilover kits apart from the competition. It’s not just a feature, really. It’s part of a philosophy that dates back to Kenth Öhlins first motocross dampers.
The theory is simple; damping oil is controlled by multiple mechanisms in both directions. High and low speed responses can be tuned independently (at the engineering level), and oil moves both ways under control. So far, so what?
It means that damper fluid flows consistently in both rebound and compression, giving the wheel and tire the ability to quickly lift, and return to the ground after any disturbance.
The result? Maximum grip and traction at all times WITHOUT sacrificing road comfort! Nice words, but you want to know more, right?
Every Öhlins R&T coilover we sell in the 4RUO Shop is equipped with DFV technology, making it the ultimate upgrade for drivers who demand comfort and agility.
How DFV Works
The Science Behind Comfort and Performance
The magic of DFV lies in its ability to adapt, with multiple levels of control, overlapping. On minor road imperfections, the oil flows smoothly through an adjustable (with clicks) needle and jet valve (see the diagrams below), delivering an OEM-like ride comfort that’s smooth and supple. On the more aggressive bumps, DFV’s ability to 'open up' other valves keeps the car stable and controlled, ensuring that traction is always available.
Other suspension systems often force drivers to choose between stiffness for performance or softness for comfort. With Öhlins DFV, there’s no compromise—every bump, crest, and undulation can be absorbed with precision. It's "just" a matter of engineering and calculation (the best bit).
This is why we at 4RUO enjoy working with high-quality components like Öhlins. We have the tools and experience at hand to make great solutions to your suspension problems.
Let's take a detailed look at a DFV valve:
Figure 1: Compression Flow – How DFV Delivers Precision and Comfort
At low shaft speeds (think slow movements, braking pitch, body roll, etc...) the damper fluid primarily flows through the damper shaft jet (lower dotted blue arrow), maintaining smooth operation for minor imperfections and body movements. This is what you can control with your external clicker, a needle progressively 'clicks' in to obstruct the jet (and that's why you should never over-tighten your clickers!, see more about that below)
As shaft speeds increase, so does pressure. Depending on how many clicks you've dialled in above, at a certain point (that we calculate at the engineering stages) the fluid forces itself through the compression ports in the piston, past the tuneable shims (upper dotted blue arrow), offering a controlled response to larger impacts. (You can't adjust these shims, but we can at rebuild and service)
During extremely high shaft speeds—like sudden impacts or rapid suspension movements—the fluid takes an additional path (solid blue arrow) through the compression ports in the DFV, reducing harshness and maintaining comfort without sacrificing control. While it's not a GT3 or Formula car 'blow-off' valve, it's still a massive part of why an Öhlins R&T damper is such a premium option at this price point.
Figure 2: Rebound Flow – Stability and Traction Perfected
The true beauty of DFV... the rebound is essentially the reverse of the compression with equally tuneable flow characteristics
At low shaft speeds, the damper fluid primarily flows through the shaft jet bleed, allowing you to adjust rebound control for body control with the main clicker.
As speeds increase, the fluid can push the shims, and flow through the rebound ports in the piston, delivering a consistent response to more significant suspension movements (upper dotted red arrow).
At very high shaft speeds, during abrupt rebound events, the fluid also escapes through the rebound ports in the DFV (solid red arrow, middle), ensuring the tyre quickly regains contact with the surface, maximizing grip and stability. Exactly like above, right?
Why It Matters:
Without DFV: After hitting a bump, the oil flow inside traditional dampers often struggles to keep up, causing the wheel to lose contact with the road after the bump. Pro Tip: Your wheels don't work if they're in the air. This is most noticeable on braking and cornering over bumps!
With DFV: The valve opens to allow faster oil flow, ensuring the wheel stays in constant contact with the road for unparalleled grip and predictable handling. Easy.
Other Key Features of an Öhlins Road & Track kit
Ride Height Adjustments Done Right
Unlike many cheaper coilover systems that adjust height by compressing or relaxing the spring (often at the expense of suspension travel) Öhlins uses a smarter approach. The adjustable spring seat can remain in its optimal position, at the correct pre-load, while height adjustments are made by spinning the lower flange on the threaded body. This means you can tune pre-load of the spring independently from the ride-height of each corner.
For real enthusiasts and track car connoisseurs, this is really the only way to properly setup any car.
(Why a 4RUO custom application is even better)
We engineer our kits to the next level, oftentimes optimising damper length (for example, in our fantastic F56 MINI Cooper Custom Öhlins Road & Track kit), by engineering our own aerospace-grade alloy top mounts with spherical bearings, utilising helper springs, our own hardware, and finally tuning caster and camber to settings that you can't achieve with a standard kit. But more about that, and our own custom engineered top-mounts in another blog post....
Precision Tuning at Your Fingertips
Öhlins R&T kits come ready to perform straight out of the box, but the real magic lies in their adjustability. Want sharp, reactive handling? Or something softer and more forgiving? With just a few clicks of the easily accessible adjuster, you can fine-tune the damping to suit your driving style and conditions. Road & Track, it's in the name.
Too much low-speed rebound damping can reduce grip, but the precise Öhlins adjuster lets you dial it in with confidence. Gone too far, back out that adjuster before the next session. It's that easy, just don't forget to count to your clicks... but we're getting to that.
Thermal Expansion: Öhlins’ Hidden Edge
Heat is inevitable during hard driving—whether it’s a spirited road run or a weekend at the Nürburgring. Many dampers struggle to maintain performance as temperatures rise, but Öhlins solves this with a unique needle bleed valve. As the damper heats up and fluid viscosity changes, the carefully developed valve material actually compensates by closing the gap, ensuring that damping performance remains consistent lap after lap.
The best part? You’ll never notice these changes happening inside the damper! What you’ll feel is a car that remains responsive and predictable, even under extreme conditions.
HOW TO COUNT YOUR CLICKS ON ÖHLINS DFV
Most Öhlins Road & Track damper have between 24 and 30 clicks. The clicks are just a nice way of measuring how far the needle is from the jet, and how much oil flows before the shim stacks are woken up.
- We always count the clicks from the "bottom", from closed. We do this by GENTLY closing (clicking clock-wise) the adjuster to the 'end'. But be careful...
- Don't force the adjuster to the last 'click', you're jamming the precision steel needle into the soft jet, and you can damage the flow! As soon as you feel the needle hitting the jet, STOP.
- Back the adjuster out (anti-clockwise) to the last click you felt BEFORE it was closed. This is click number 1.
- PRO TIP: NEVER EVER drive on 'closed' clicks, or even in the bottom 2 clicks. Depending on the application, the needle is close enough to the jet that under extreme use, it's possible that the thermal expansion of the jet could 'pinch' the jet and damage both.
Why Settle for Second Best?
When you choose Öhlins R&T with DFV technology, you’re not just upgrading your suspension—you’re redefining how your car handles every road and track scenario. Whether it’s the daily commute or a fast lap, Öhlins ensures you experience the perfect balance of performance, comfort, and reliability.
WAIT>>> What if I want to tune the rebound independently from the compression?
The smarter amongst you will have seen the limitation already... the single clicker on a R&T DFV kit controls your rebound and your compression at the same time. The ratio is engineered at source, and can be tuned by adjusting shim stacks at build or service.
For most of our customers, this level of adjustability is enough to change their road car to a capable track car with just a few clicks. But if you're tuning per circuit, per tyre, per driver... then you're gonna need the next step up - Advanced Öhlins TTX dampers, which really are the same beautifully machined and engineered dampers you'll find on vehicles as diverse as GT, Formula and even Stockcars. But that's a whole other blog...
