Niner's on a mission to build the best 29in mountain bikes in the world, but building the perfect bike doesn't necessarily mean loading it up with space age suspension and two meters of travel. When you want to pedal, flow, and climb, a hardtail's where it's at, and the 2016 Niner Air 9 Carbon Mountain Bike Frame is a steed that'll charge smooth, fast trails with plenty of power and a surprising amount of forgiveness. Carbon's known for being stiff and light, so it's the most efficient material when pedaling speed is of the essence. Modern layups are far more durable than traditional carbon constructions, too, so one spill won't spell the end of your frame. Niner uses a special computer based finite element analysis when designing its frames, and in this case the end result is a series of optimized weaves, layups, and tube shapes that save weight and increase strength. The Air 9 Carbon isn't as space shuttle light as the Air 9 RDO, but it will still have you blasting up climbs and leaving your buddies in the dust. The elegant lines of the chainstays and seatstays look great, but they're actually designed to reduce chatter and guide stresses to the strongest parts of the frame, and the chainstays and bottom bracket have a hefty design that sends torque straight to the back wheel without losing power through excessive flexing. There are even titanium plates incorporate into key spots to prevent chain slap and rock chips. To max out the Air 9 Carbon's capabilities, Niner recommends mounting up an 80 to 100mm suspension fork, or a rigid unit preferably from Niner. You'll need a 31. 6mm seatpost and a 35mm seat clamp. The rear triangle offers clearance for tires up to 2. 4 inches, although there are variances across tire manufacturers, so some of the largest 2. 4s may not fit.