Twentyniner XC rocket with competition genes! The F-Si has since its release in 214 itself won a lot of fans and shown potentials where none were suspected. From its asymmetrically offset rear triangle and drivetrain to its new-school geometry and custom offset Lefty, every part of the F-Si was designed as a System, fully Integrated in the pure pursuit of speed. The F-Si is the most integrated, most advanced and fastest XC race bike ever made and comes now also in Smartformed aluminium alloy. It got nearly the same geometry but without the asymmetric drivetrain. Shimano XT/SLX 1x11-speed shifting components underline the standard of this bike, guarantee highest precision and durability. The stiff Cannondale Si crankset in connection with the BB3 bottom bracket does not waste a single watt. Hydraulic Shimano Deore disc brakes enable a powerful and save brake performance in all conditions. A solid wheelset with Stan's Rapid rims forgives even tough line choices and can be prepared for tubeless setup. Cannondale F-Si Alloy is a pure expression of aluminium artistry! It is made of 661 aluminium alloy and heat-treated to a T6 hardness for strength and durability. The shape optimized tubing helps reducing weight and increasing strength. The trademark smooth weld technology eliminates the stress-risers and weak points found on traditionally welded frames. The SAVE Stays with its optimized chain- and seat stay shaping offers lateral rigidity, while providing vertical compliance for bump absorption and comfort with no loss in power transfer. System 29 Geometry When it comes to the way a bike handles, geometry is everything. The difference of just a few millimeters here or a half a degree there can significantly impact handling. Cannondale developed a winning 29er geometry for the F29 but World Cup competition is changing. With courses becoming ever more technical, steep and brutal, they knew that they have to rethink XC geometry completely. The result is F-Si - a bike that defines new-school XC handling and speed. Super Short Chainstays: Category leading, super short (436 mm) chain stays, which were extremely agile in tight and technical terrain, especially when navigating switchbacks. That also puts more of the rider weight over the rear wheel, dramatically increasing rear wheel traction on steep climbs. Slack Head Angle with 55 mm Offset Lefty: Progressively slack 69.5° head angle mated to the Lefty's proprietary 55 mm fork offset, the nimble rear end is complemented by equally agile and capable steering. At high speeds, the added stability of the slack head angle enables the rider to attack rough terrain with confidence. In slower, tight, technical sections, the extra fork offset and resulting lack of "trail keep the steering quick and nimble. Lefty 2. A bike as radically new and boundary-pushing as the F-Si demands an equally radical fork to complement its freakish handling and stiffness. For the uninitiated, Lefty has always been the lightest, stiffest, smoothest, and most durable front suspension on the start line: XC+ Damper Who says an XC rocket can't borrow technology from the enduro world? The new Lefty gets the same new smooth and supple damper technology found in the new SuperMax forks, but tuned for XC. Dual Integrated Crowns Stiffer and stronger than single crown setups. The Lefty 2. has multiple clamp widths, lowering the front end heights of Cannondales small, medium and large sizes. Inverted Design Inverted design is not just stiffer and stronger, it's also better lubricated. Gravity holds lube against the seals and bearings for longer life and smoother action. Oversized Clamp Area The Lefty gets an updated structure which grows to 44 mm in diameter at the clamp areas. This keeps the fork svelte, but adds even more stiffness and strength. Hybrid Needle Bearing System For maximum control, SuperMax's proprietary needle bearing assembly keeps the suspension smooth, no matter how hard you brake, corner, or land. New 29 Specific Offset To complement the F-Si's ninja-like rear end handling, the new Lefty uses a 55 mm offset, which is longer than the competition. When combined with slack head angles, this creates the perfect balance of high speed stability and low speed agility. Overall it offers 1 mm air suspension, a hydraulic remote lockout and adjustable rebound damping. For 217 it comes with a new air spring assembly, called 2Spring. This internal update decreases the strut's activation force by 7 lbs and makes for longer service intervals.