Niner Bikes has continually pushed development of the 29er hardtail category and the Air 9 Carbon RDO Frameset now features Boost 148mm rear spacing. In the carbon fiber category alone, Niner has steadily improved these frames year after year. Some of these advances come from rider and consumer feedback, and some from technological advances. The new Air 9 Carbon RDO has elements of both. Niner's Carbon Compaction System (CCS) has delivered substantial improvements in stiffness, durability and ride characteristics, while dropping 100 grams from the previous version. The CCS process uses rigid internal molds, which increases the level of compaction and precision in wall thickness. This reduces resin build-up from the compaction process and the end result is a frame that is internally clean and clear of excess material, and much greater control over the construction itself. The frame now features a Boost 148mm/12mm rear drop out, with a replaceable derailleur hanger and increased lateral stiffness from the bottom bracket to the rear axle, resulting in better power transfer. The headtube also benefits greatly from CCS, creating an overall stiffer interface at this crucial junction.

Increased stiffness and power transfer haven't come at the expense of the Air 9 RDO's excellent ride qualities. The tube shapes and sizes are maximized for torsional stiffness but optimized for vertical compliance and vibration attenuation. The flat profile of the tubes actually act like minute travel suspension, giving just enough to take the shock and impact from the rider. If that isn't enough, the new frame offers enough room for a 2.4 inch wide tire for great grip and a smooth ride at lower pressures. The Air 9 RDO was designed with the understanding that the vast majority of riding time is going to be spent pedaling from the saddle, so the frame has offer enough comfort to manage the physical stress of long hard efforts. Not all carbon hardtail's are the same, and Niner builds the frame to be buttery smooth (their words). Despite the minimalist carbon lay-up and overall lightweight, Niner's RDO level frames meet the most rigorous EN standards for carbon mountain bike safety in strength and impact protection.

The Air 9 RDO geometry is informed, by it's lineage, but not limited to it. This design, with it's increased headtube strength, can accommodate forks with up to 120mm of travel without losing the stable ride, precise handling, and speed you have come to expect. Your headtube angle with a 100mm fork at standard sag will be 70 degrees, and 69 degrees with the 120mm. The resulting slightly quicker handling and increased bottom bracket clearance running a 120 will favor the rationale for more travel- increased descending and technical trail capability, such as that found in marathon racing or multi-day epic events. Check the variations in the geometry chart for the 100/120 set-ups for more detail. Overall the XC race geometry holds true and consistent with the RKT9 RDO when set-up with 100mm travel.

If you haven't ridden a newer Niner carbon hardtail you are missing out, and the Air 9 RDO is the best yet. You'll love the move back to the 27.2mm seatpost for more flex and overall comfort. The option for a 120mm travel fork opens up this speed merchant to longer distance, more technical riding. The ride quality is one of the best we have ever experienced, and you don't sacrifice power, handling, or overall performance in any way. Progress in frame development means continual improvements and we are sure Niner will top this frame eventually, but if you are XC racer or just a flat out fast trail enthusiast who prefers the rolling speed, contact patch, and incredible stability of a 29er hardtail, you owe it to yourself to experience the Air 9 RDO.