2019 Cannondale F-Si Carbon 4 Mens Mountain Bike - Charcoal Grey

The Cannondale F-Si has always been about pushing the limits of what an XC hardtail is capable of, and the new version pushes it harder and further than ever. No other hardtail descends as fast, climbs as nimbly, or kicks harder, smoother. With the otherworldly performance of the new Lefty Ocho, you've got a whole-new level of XC capability, tailor-made to feed the needs of the XC obsessed.

At just 900 grams, the all-new F-Si is the lightest mountain bike frame Cannondale have ever made. It shaves 80 grams off its predecessor, and when you factor in the svelte new Lefty Ocho, you save a whopping 330 grams on the frame and fork. What's even more impressive is that, rather than chasing marketing grams, Cannondale engineers focused on features that deliver real performance benefits out on the course - features such as Ai and OutFront, or improved compliance or improved durability. That's what wins races,  not saving the weight of a few sips of water.

The all-new Lefty Ocho is the smoothest, stiffest ultra-light XC fork ever made. It floats through chop and steers through the choss like nothing else.

Short chainstays do wonders for traction and nimble handling, but they usually come at a cost. Not with Ai - this proprietary Asymmetric Integration drivetrain offset moves the gears and rear triangle over, helping creating space for much shorts stays while still having the clearance for big tyres and 2x drivetrains if you so desire. It even creates a stiffer, stronger rear wheel by evening out the dish.