Sure, there are plenty of lightweight XC forks out there, but racing demands so much more. Nimble handling, gram-obsessed weight, buttery damping—combined they all make the difference between a good fork and a great fork. And with this in mind, the all-new RockShox SID World Cup Brain fork has been completely redesigned to meet the demands of XC racing, and hyperbole aside, we can confidently say that it sets the bar for race-worthy performance. The new SID has many new features, but the main attraction is its use of our proprietary Brain technology. Made famous on the rear of our Worlds-winning Epic, the Brain system knows the difference between rider and terrain inputs—staying firm in hard accelerations on smooth ground, and effectively soaking up imperfections when the trail decides to fight back. This translates to the highest efficiency possible when hammering up climbs, and smooth compression on the descents—all without ever having to flick a switch. The World Cup Brain edition of the SID is not just a slight upgrade over the RLC and XX models. Along with the integrated Brain technology, it utilizes a carbon fiber steerer and crown, which reduce weight by over 100 grams and increases the overall stiffness. Also adding to the stiffness of is the short-travel-specific design. Leaving the 120-millimeter segment to the trail category, RockShox’s engineers were able to focus on the 80- to 100-millimeter travel range, and therefore develop lighter and stiffer uppers and air shafts. This new design, along with SRAM's Torque Caps (they create an enhanced interface between the hub and fork dropout), Power Bulge technology that reinforces the lowers, and 110-millimeter Boost spacing, keeps torsional stiffness high, allowing you to point-and-shoot while descending. Last, but certainly not least, on the feature spec is the Solo Air spring that’s customizable with RockShox’s Bottomless Tokens. The Solo Air spring lets you adjust pressure with a single Schrader valve that controls the pressure in both the positive and negative air chambers, making adjustments to pressure simple and intuitive. To customize ramp-up preference, RockShox’s Bottomless Tokens can be added to create a suspension curve that’s custom to your preferences.