ND Tuned is a Portuguese aftermarket suspension tuner that’s creating some interesting hop up kits for Fox and Rockshox forks, plus a lightweight, fully adjustable coil spring for downhill. Starting at the front, the OVR Intelligent System cartridge uses a fully pneumatic damper to drop about 200g off your fork’s weight, yet still gives you complete control over the damping. What puts it over the top is they also claim it provides about 10% to 15% more usable travel!

ND Tuned OVR Intelligent System air damping cartridge for rockshox and fox mountain bike suspension forks

OVR stands for Opening Valve Resistance, which hints at how it works. Much like with an oil-based damper, it’s simply controlling the flow rate of air through the internal ports and valves. The video above show somewhat how it works, with a bit of a language barrier.

We reached out to them to see how, exactly, a damping cartridge could extend the usable travel of a fork, and here’s the answer: With a traditional damping cartridge, only the air spring side is supporting the rider, and sag is typically set at ~25%…which means you only have ~75% of your travel left to absorb bumps when the suspension is loaded.

With OVR installed, you can reduce the air spring’s pressure to around the same psi as your body weight (give or take, depending on fork model) because the air pressure inside the damper is also supporting your weight. They say this translates to a sag of around 10%, which frees up 10% to 15% of your travel to be used. And all this without making the fork feel overly harsh. We do suspect there’s a bit more of a breaking force required to set things in motion, hence the “no pedal bob” claims, but for racers seeking every incremental gain they can, a 200g drop is massive.

And it’s all yours for about €390 and a couple weeks without your fork…they say it has to be factory installed. They offer it for the Rockshox SID, RS-1 and Reba, and the Fox 32 Performance and 32 StepCast forks.

ND Tuned aftermarket steerer tubes and stanchions for mountain bike suspension forks

…as do their aftermarket stanchions and steerer tube. The 32mm stanchions (also for Fox and Rockshox, only) get a 40 micron thick hard anodized black coating to maximize stiffness and smoothness. Prices range from €109 to €114, available for 26″, 27.5″ and 29er forks from both brands.

ND Tuned DH zxRC3 worlds lightest weight coil shock for downhill mountain bikes

The DH 2xRC3 coil shock claims to be the lightest such thing on the market, yet still gives you external controls high/low speed compression and low-speed rebound. Spring rates are offered for various rider weights, and preload is set with the adjuster ring. The outside is 100% machined from alloy, and inside is a “high performance” oil.

ND Tuned DH zxRC3 worlds lightest weight coil shock for downhill mountain bikes

Retail is right at €800, plus the cost of the spring, sold separately.

The brand also makes aftermarket tuning circuits for motorcycle suspension. We found these products in their distributor’s tent, so check MRC-trading.de for info, and use Google Translate as necessary.






  1. That might be psuedo- extra available positive travel, but it will come at a cost of increased ride height and an effective decrease in negative travel. Basically, that travel increase only exists when the bike is sitting still, as soon as you start moving and the suspension cycles through impact/rebound then the sag point becomes irrelevent and you have the same amount of usable travel as you ever did.

    • Mountain bikers always refer to sag & total travel.
      Automotive engineers refer to bump and droop travel. (Partially because sag is static on most if not all cars because the weight of the car rarely changes).
      This concept of droop travel is very rarely, if ever, discussed in regards to mountain bikes. However, it is quite an important concept. It’s going to be what keeps your front wheel on the ground & having traction (especially helpful under braking) even if there is suddenly a hole in the trail, or you ride off the edge of a root, etc.
      If this damper removes a lot of that droop travel by lowering the amount of sag required, it might not ride very well at all.

      Side note: I used to ride a Giant NRS. It was intended to be setup such that the rear suspension was never in sag under normal riding conditions. It was intended to be balanced on the edge of compression travel. It didn’t ride nicely because of that, and you had to have the rebound super slow, else it was always trying to buck you off the bike (when it topped out). Rear wheel traction under braking also sucked because the wheel wasn’t following the terrain, only responding to bumps, not able to respond to holes, drops, etc.

      • Mark…like everything in MTB and cycling, there is a specific terminology. What you are talking about bump/droop, is the same thing as positive/negative travel. I have gotten into arguments about this stuff on the forums, and you just have to accept that people develop their own language to express the same things.

        • For sure.
          I was just pointing out that droop / negative travel is rarely discussed in the bike world, but is very important for proper suspension function.

  2. I’d love to see how an air sprung air damped system has no bobbing. It’s practically impossible to create enough damping force using air as the medium, as it can just compress. In any impact, the return force can only be as much as two air chambers, as that’s what happens to the “damping” chamber. It turns to a spring until the air can make its way through a valve.

    • HUH? Are you just making up negative comments. The idea and concept of an air damped fork is not new. K2 bikes used a similar concept on their Razorback full susser in the late 90’s. I worked brilliantly. the only drawback was it required more maintenance because of there being less lubricant in the fork. It needed to be serviced every 10hours to perform reliably. As far as the damping goes it was really pretty good and quite simple.

    • When you gave pressurized Air at 300 pois psi you can. I can lock my ovr equiped SID on the bottom if i fully close the rebound. You should see to believe

  3. As a once user of Englund Air Cartridges…I will never recommend air damped suspension. The dampening was inconsistent. Seemed to change on long descents. And temperature was an issue with consistency. Reliability was also a problem. Had one fail on Porcupine Rim, next day was Slickrock and I had to do it on a rigid fork as I remember.

  4. This thing sounds like it’s going to be pretty hard to tune. Does it only effect compression? Does it also screw up the rebound on the fork so it ‘packs up’ under successive hits? That’s one of the major complaints of forks with a lot of compression damping.

    Also, the acclaimed benefits sound like marketing fluff.

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