The big news from X-Fusion is their completely redesigned 'Roughcut' damper that sees the company move away from the twin-tube, emulsion style system that they've longed employed in their popular Vengeance mid-travel fork and RV1 downhill offering.
Both the Vengeance and RV1 have been highly praised, so it while it does come as a bit of a surprise to see X-Fusion abandon those proven internals, it's also no secret that the new sealed and bladder-equipped dampers from FOX and RockShox have raised the game. The new Roughcut damper does use a similar design, complete with an expanding bladder to compensate for oil displacement and to provide back-pressure to limit cavitation, but it's important not to forget that bladders have been used in suspension for many, many decades. The improvement in performance is big enough for Joel Smith, X-Fusion's General Manager, to say that it's ''the single best product that we've ever made,
'' which is no small claim.
X-Fusion's goal with the Roughcut, and the ideal behind any sealed damper that's free of air, is to provide more consistent damping. An open design where the air and oil are allowed to mix is inherently less expensive to manufacture due to the simpler layout, but the difference in performance comes after a few minutes of riding on sustained rough terrain: the emulsion damper will begin to lose performance as the air and oil slosh together and foam because that foamy oil is now flowing through the damping circuits. The sealed damper that has no air inside of it will offer much more consistent damping because the oil won't foam up to nearly the same degree. This is why nearly all high-end suspension, including both forks and shocks, are bled free of air and use some type of compensator.
The compensator, which is the rubber bladder on the Roughcut, is what allows for the damper to be completely full of oil and have no air in it. As the damper rod goes into the the fork, oil is displaced and the rubber badder expands to allow for that displacement. Without it, the damper would not compress - it's either allow for air in the system or use a compensator.
The Roughcut sees X-Fusion invert the damper's architecture, with the compression assembly and both high- and low-speed adjuster dials atop the right fork leg and the low-speed rebound knob at the bottom. The previous damper saw the compression at the bottom because the air in the system would rise to the top during use and X-Fusion wanted to keep it out of the compression circuits. The new damper is bled free of air, though, and the compression dials are now moved to the top for easier access.
And while on the subject of dials, Smith explained that the new design also makes for a much more consistent adjuster range compared to the older layout, with each click offering a near similar difference in damping regardless of where on the adjustment scale you are. This applies to the sixteen-click rebound and both the thirty six click high- and low-speed compression adjustments. There's also less ''crosstalk'', which means that each adjustment is far more independent of the others, so adding a few clicks of rebound won't effect the fork's compression feel.
X-Fusion is dyno testing each and every Roughcut damper before it leaves the factory, and they've actually just begun to ship forks with 34mm stanchion tubes and Roughcut dampers, so consumers will be able to get on it very soon. That said, Smith was keen to note that this isn't something that's been rushed out the door, with X-Fusion rider Brian Lopes actually using an early prototype to win at least year's Sea Otter event. Expect forks that feature the Roughcut damper to go up by about $100 USD in price (note that's still less expensive than their competition
), and the damper will be offered as an upgrade for older forks in its second year of production.