Niner’s CVA™ Suspension system:

Niner spent over a year in development before releasing the Constantly Varying Arc (CVA™) with one goal in mind: creating the most efficient, most active suspension design on the market.

Niner started with a clean sheet of paper and tackled the concept of what Niner’s first suspension bike should accomplish before dialing in the design. For starters, Niner wanted the suspension bike to be pedal efficient. Both Steve and Chris agreed that a suspension system that needed a “pedaling platform” rear shock was an inefficient system. The “pedaling platform” valving in the rear shock is actually just a mask for a bike that wants to react to input from the chain. Needing to dial the shock into a specific valving mode or to full lock out means that the suspension is less useful, and let’s face it, just because you’re pedaling, doesn’t mean you don’t want your suspension to work. So Niner wanted the frame to be truly “pedal neutral” without need for a lock out or platform damping. That’s not to say that those things aren’t still useful, because no matter how hard you try, you can not cancel out inefficient pedaling (i.e.: rider bobbing) and weight transfer of the rider (on those brutal, out of the saddle climbing sections) from the suspension system, so lock out levers and pedal platform damping still have their place. The second design parameter for Niner’s full susser was that the suspension design should be fully active. On many other suspension designs, the movement of the suspension is limited while pedaling or braking or both. Niner’s goal from the beginning was to use a suspension system that was fully active regardless of whether or not the chain was under tension or the rear brake was being applied. Thirdly, Niner wanted the suspension to be “brake neutral” as well. Meaning that braking forces on the suspension system do not affect travel of the suspension nor do they cause “brake jack”. Lastly, the suspension design we would ultimately use for the Niner full suspension frame had to fit around Niner’s design parameters regarding geometry, most notably a short chainstay. Even if we found a design that worked for the first three issues, if it forced us to use an excessively long wheelbase, it was essentially no good. Getting these four items to line up on one suspension design was akin to hitting the lottery, but Niner set out to do just that (we think this bike does hit the lottery).

Within months, the infancy of CVA™ suspension was born. With the development of the Constantly Varying Arc suspension design, Niner accomplished everything they set out to accomplish, and with a suspension design no more complicated than any other four bar suspension system on the market (it’s important to note that the CVA™ suspension system still only has four pivots, no more than a Horst Link or other four link bikes). In its earliest stages, Niner built prototype 6” travel CVA™ frames in 26” wheel incarnations to compare back to back with other designs on the market place. As we moved forward with the R.I.P. 9, we then built a 6” travel version in 29” wheel to test the limits of the design. If the design was going to show flaws, it would most certainly show up in longer travel modes. Decreasing travel in a working suspension design is much easier than increasing it. After months and months of testing, the R.I.P. 9 was born, but it too, needed tweaking before final production. We went through three different prototypes fine tuning link angles and cosmetic treatment until finally we arrived at our original destination: An all mountain 4.5” travel bike that can climb like a Billy goat and descend like an Eagle in full attack mode. From there, the Niner R.I.P. 9 worked its way through the cycling community gather up awards and praise along the way. Niner knew, however, that the buying public was eager for something shorter and lighter weight, so we reduced the travel and redesigned the R.I.P. 9 from the ground up for the introduction of our second full susser; the Jet 9.

So what is CVA™ Suspension? Niner’s Constantly Varying Arc suspension design has a tuned wheel path with a wheel arc that constantly changes throughout the path of suspension travel. Niner was able to dial in the exact wheel arc required to meet the goals as stated above, “pedal neutral”, “brake neutral”, and fully active were all accomplished with a wheel path using a constantly varying arc. The wheel arc of the CVA™ system works to counter forces from the chain, keeping the “instant center” of the suspension design in line with the torque of the drivetrain. Finding the balance so that the system works in every gear is critical and every single millimeter or degree (or both) could hinder the performance of the suspension. In addition, Niner’s CVA™ wheel arc was tuned to keep chain growth at a minimum, insuring that the torque on the chain would not cause suspension movement.

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Check out the R.I.P. 9’s suspension as it cycles through its full 4.5” of suspension travel. As you can see, the beginning of the stroke is rearward, moving the wheel back and away from the drivetrain. This rearward axle path settles into the top of the arc almost exactly where the sag of the suspension should be set, from that point forward in the suspension travel, the wheel arc is constantly moving back toward the main triangle at a variable rate. This rate is perfectly tuned to keep chain tension equal which eliminates pedal induced suspension movement. In addition, with the wheel in the rearward most position after correct sag has been set (25%), the CVA™ suspension has increased small bump compliance. Even with the chain under full torque load on a killer steep uphill section, the CVA™ suspension is still completely active over even the smallest obstacle. As the suspension cycles through its travel, it also becomes “regressive” in nature counteracting the natural “progressive” feel that all air sprung shocks have. This means that the R.I.P. 9 can utilize the full range of motion from the air shock, instead of ramping up too quickly which inevitably causes the suspension to stop short of the full claimed travel. Unlike most bikes, the R.I.P. 9 actually gets the full 4.5” of travel as claimed (if the shock is set up correctly). Using all of these same principles, Niner was able to get the full, claimed 80mm of travel out of the new Jet 9 as well.

Is your brain starting to hurt? Niner understands that this is a lot to take in so we’d rather you just tried it for yourself. Throw a leg over a Jet 9, and tell us what you think. Does the CVA™ suspension design live up to the hype? In our humble opinion, there’s no better system on the market.