SEA OTTER CLASSIC 2010 – Having proven that air suspension can work for long-travel downhill applications with their Boxxer World Cup, Rockshox is helping downhillers drop a full pound from their bike while improving their performance with the new Vivid Air shock.
Pro rider Mick Hannah was on hand to testify that an air shock can indeed perform at the World Cup Downhill level, saying that during 7- to 8 minute test runs, the shock let him push harder into the corners and rebounded faster, letting them rip through sections that might bog down other shocks. It does this by keeping the shock higher in the travel because the air shock uses less of its stroke to achieve the same travel versus a coil shock. Thus, it rebounds faster from a big hit.
Another performance gain came from development of a Twin Tube Solo Air canister and an alloy/thermoplastic rebound adjustment needle called Hot Rod. More pics and info on all that after the break…
While the Vivid Air looks larger, the outside diameter is actually just slightly smaller than the coil’s diameter, so it’ll fit any frame that the coil version does. There are also two different air valve placements available, as shown in the top pic. If you’re not quite sold on air after reading this, don’t sweat it. The Vivid Coil also gets the Hot Rod and some new tuning and a new 90º rebound adjuster.
The Twin Tube Solo Air is a new development that allowed the Vivid Air to control ramp up at the end of the stroke. With a single “tube” canister, as the shock compresses, the air has nowhere to go and it’ll ramp up pretty steeply. With the TTSA, there are small holes at the top of the canister (on the left in the pic above, not visible) that let air spill into the outer section of the canister. The black rubber piece surrounding the shaft is the bottom out bumper.
The other new development is the Hot Rod beginning stroke rebound adjuster. The front needle is the original design from the coil version. As you dial it down to decrease rebound speed, the pointy end of the needle closes into the hole that the oil flows through…the smaller the orifice, the slower the flow and rebound. As the oil heats up, it becomes more viscous, and can flow through a given opening faster. On a long downhill run, this would translate to increased rebound speed as you fly down the mountain. In order to maintain consistent rebound damping performance from the start gate to the finish line, Rockshox engineers created a thermoplastic section that expands ever so slightly as the oil heats up, thereby compensating for the increased viscosity and keeping rebound speed consistent. Easy, right?
Well, they’ve been working on this for quite some time and have gone through a lot of iterations. Rockshox’s Long Travel Product Manager Jeremiah Boobar said the change in length is so minimal that it took a lot of testing to figure out how much material was needed. The end result is an air shock with virtually no fade thanks to self-regulating temperature management technotrickery.
There are three external adjustments on the Vivid Air: Compression damping (blue knob), Ending Stroke Rebound damping (silver bolt, adjusted with a hex key) and the Beginning Stroke Rebound damping (below, red knob), which is the Hot Rod dial.
For the pro tuner or shop mechanic, they can insert internal spacers in the air canister to reduce overall volume and create more ramp up.
Boobar says the Vivid Air saves about a pound over the standard steel coil version, and about a half pound over a similar shock with a titanium coil spring. There will be a short 200 x 51 size for freeride applications, and larger sizes for downhill bikes.
