The new RockShox Vivid Air shock
has created quite a buzz, but up until now riding impressions have been hard to come by. I spent a good part of my time today charging hard with the new air sprung downhill damper under me and inside you can read my thoughts on the new lightweight DH shock. You'll also find pictures detailing the Vivid Air's internals, including the novel Hot Rod thermoplastic temperature compensating rebound needle.Read on...
Vivid Air R2C bolted to my Nomad test bike
Its no longer a secret that RockShox is getting very close to releasing an air sprung version of their proven Vivid coil shock. As downhill racing progresses and the top riders (along with the regular joe's
) are looking for lighter and lighter bikes, being able to drop 300-400 grams by replacing their coil sprung dampers with an air version is looking more like it is beginning to be a viable option. While simply bolting on a long stroke air shock may be an easy way to loose some weight, it isn't that simple. Standard air shocks have two distinct disadvantages to their coil spring brethren: higher amounts of friction due to having to deal with more seals, and more importantly, changing spring and damping rates as they heat up over long runs or demanding terrain. The new Vivid Air tackles both of these problems head on.
RockShox Vivid Air R2
The Vivid Air uses a new Twin Tube Solo Air spring which is exactly as it sounds, two air canisters that share the same duty. Looking at the body of the shock you'll quickly notice the increased size of the air canister, but what you're actually seeing is the outer air chamber. Between the two is an air bleed hole that creates one large chamber. This has two benefits to the performance: firstly it creates a more linear spring rate that is compatible with a wider range of bikes and doesn't suffer from excessive ramp near the end of the stroke, and secondly, the larger volume is better able to cope with high operating temperatures without suffering from excessive spring rate changes as the air heats up. The twin air canisters also add another level of tuning with the ability to use specific shims that take up volume within the outer can which a rider can use to fine tune the spring rate. While this type of technology certainly isn't new to shocks, it is ideal for the Vivid Air's intended use.
The Vivid Air uses two air cans, one within the other, with the ability to fine tune the spring rate by adding or subtracting plastic shims to the space between the two.
What is new though is the Hot Rod damping needle hidden within the shock. To explain how the Hot Rod works, I'll first talk about why it could be a big deal. Even though the average downhill run will be over relatively quickly when compared to the average cross-country loop, the shock on a DH bike will see faster shaft speeds and much higher temperatures during that time. Ever feel your shock after a hard run? It will be quite warm to the touch. As the shock gets hot, the damping oil will warm up as well and get thinner, and therefore it won't provide the same amount of resistance it passes through the damping circuits. RockShox's solution is to change the damping to match the hotter and thinner oil, hopefully resulting in greater consistency throughout a run. They do this by using a small piece of temperature sensitive thermoplastic (with a resin core
) that self adjusts as the shock gets hotter. In simple terms, as the shock gets hot the thermoplastic expands and the rebound adjuster needle actually gets longer, therefore providing increased damping. As the temperatures inside the shock lowers, the rod contracts and returns to it's original length. Its a simple idea that took 2.5 years of development time to prime it for production. But does it perform as advertised?
RockShox Vivid Air details
The Hot Rod rebound adjusting needle. The black piece just above the tapered end is thermoplastic and RockShox claims that it expands as the shock heats up during long or difficult runs to compensate for damping fade
• Air sprung shock designed for downhill and all-mountain use
• Twin Tube Solo air spring for a supple and linear coil feel
• Uses new Hot Rod thermal compensating rebound needle
• Air can/valve can rotate to accommodate different frame designs
• Up to 400 grams lighter than a Vivid Coil shock
• In development for 2.5 years
• Two models: R2C and R2
• Available in five lengths: 9.5" x 3.0", 9.5" x 2.75", 8.75" x 2.75", 8.5" x 2.5", and 7.875" x 2.25"
• MSRP $620 USD
This would be my first ride on the new Vivid Air shock and the boys in Durango lined up a fast and rowdy downhill for me to have a proper go on it. Not only were the speeds quite high, the run was also over ten minutes long. A perfect place to see how well their new Hot Rod equipped air shock would perform. Besides having to set your air pressure for the proper spring rate, all adjustments are the same as the original Vivid coil shock. My Nomad was equipped with the higher end R2C model which means that I dialed in my low speed compression, as well as both the beginning and ending stroke rebound before hitting the trail. Pushing on the seat gently proved that the new Vivid Air is as supple as one could ever hope for. New seals and polished inner air can surfaces help to enhance this feeling. What I was really interested in was how the new shock performed at speed, especially near the end of a long run. I was impressed with how the air shock tackled the fast and rough sections of our test track. To be completely honest, if it had been a blind test I doubt I would have guessed that it was an air sprung shock. In the fast rocky sections I felt none of the harsh spike or very slight delay that other air shocks seem to suffer from at high shaft speeds. The lack of friction within the Vivid Air must surely have played a part in this sensation, or lack of it. After a fast nonstop run the shock felt every bit as composed as it did at the beginning of the run. I could feel that the shock body was quite warm when I put my hand around it after a run, but the rebound speed was the same as at the top of the mountain. Of course the disclaimer is that I'm far from a pro level rider and probably wasn't pushing the Vivid Air anywhere near it's limits, but I was impressed nonetheless. Just like anything else new in a high performance sport, I'll be believer when top level World Cup riders start to use the new shock day in and day out.
The Vivid Air uses the same damper assembly as the coil version
I only spent half a day charging hard with the Vivid Air under me, but I was impressed with how it performed. Like I said above, if it was a blind test I would have guessed that it was a coil shock. One of the highest praises one can make about their suspension is that it felt invisible, this is exactly how the new shock felt. While built to handle the rigors of a World Cup DH course, I could see a lot of aggressive all-mountain orientated riders reaping the benefits from this technology as well. Light weight with coil sprung performance, just what a lot of us are looking for. Keep in mind that while I'm obviously happy with how it performed, this was only a short test. Look for a long term review down the road with much more in depth impressions. Stay tuned!Rockshox.com