The new AIR 9 RDO is a product of the [R]Evolution of our classic twenty-niner hardtail. We’ve learned so much since the early days and applied that knowledge of geometry and materials to meet the ever-changing demands and riding styles of the modern mountain biker. What we’ve created is undoubtedly the best race and high performance hardtail we’ve made to date, one that will give you all the versatility, durability and performance you’ve come to expect from Niner.
The new frame’s identity has been refreshed with a bold design aesthetic. Continuing the lineage that began with RKT 9 RDO the strong, overbuilt shapes that define the meat of the frame let you know it’s got plenty of horsepower under the hood. But to keep the ride smooth, the sleek tubes that comprise the length of the cockpit and seatstays are designed to dissipate racetrack roughness, helping keep your wheels glued to the ground for great off-the-line acceleration. All you have to do is pedal damn it!
The [R]Evolution geometry of the AIR 9 RDO caters to the racer and rider who places a premium on a snappy, race day whip. Following the lead of the redesigned RKT 9 RDO, the new AIR drops the handlebar height to put the rider in the attack position and ready to charge. Lengthening the cockpit and slackening the head angle further lends to that race-ready feel and adds to the razor sharp handling when slashing singletrack at speed. If you’re a rider looking to increase the fun factor, yet still want the lightest, fastest hardtail we offer, the all new Air 9 RDO is now compatible with 120mm travel forks. The 120mm fork will transform the Air 9 RDO from a racetrack taming weapon into a comfortable, all day trail ripping machine by bringing the bars up and shortening the reach to a more neutral position. And out back, the chainstays were shortened up, but not too short making the bike twitchy. Instead they shed 4mm to a targeted 435mm, so you still get lightning fast acceleration without giving up the balanced handling and on-the-fly stability you need in a race day rig.
For a carbon structure to be as light, strong and durable as possible, the layers of carbon cloth need to be properly aligned with as few voids and extra resin as possible. This is why the AIR 9 RDO frame is built using our Carbon Compaction System. By wrapping carbon around an EPS foam internal mandrel and then compacting the entire system inside a mold, we are able to control wall thickness throughout the frame and force out any excessive resin while the frame cures. What we achieve is a 10% reduction in frame weight with a fully-engineered carbon layup that delivers everything you want in a hardtail race bike.
Originally lauded to improve the geometry and kinematics of full suspension frames, Boost 148 has similar benefits for the humble hardtail as well. Widening the spacing of the rear dropouts creates a structure more able to resist twisting, but just as importantly, it enables stronger wheels because of improved spoke bracing angles. This crucial geometry revision also allows the engineers to tuck the rear wheel closer in to the bottom bracket while maintaining ample tire clearance and the ability to run up to a 38-tooth chainring.
Versatility is one of the attributes that has become a Niner signature feature over the years and it finally gets the full carbon, RDO treatment. The oversized bottom bracket area of course provides a robust platform for pedaling and overall handling, but now it also gives you the choice to run almost any crank and bottom bracket combination imaginable. The PF30 can be run standard for the lightest race day power plant option available, but if single speeding is your gig, then no worries. Easily install the patented Niner BioCentric 30 bottom bracket cups to give you chain tension and geometry adjustability for your single speed setup, or do it even if it’s just because you prefer running 24mm spindle cranks. Never before has a full carbon race bike given you so many options.
In this age of internal routing and ever-changing drivetrain options, the AIR 9 RDO features a window under the bottom bracket for easy service. Pull the plate off the window and get instant access to any wires and cables routed through the downtube, all without the need to remove the cranks and pull the bottom bracket. Replacing cables and routing Di2 wires has never been easier.
It’s no mystery that a seatpost can add greatly to the ride feel and comfort of any bike. In an effort to provide you a compliant perch atop the AIR 9 RDO we turn to a smaller seatpost diameter. The 27.2mm post allows a strategic measure of sway, especially when it’s our RDO carbon fiber post, tuned to add a targeted amount of flex.
The only metal in the AIR 9 RDO is found in the brake caliper mount on the chainstay. Threading the calipers on here provides them an amount of protection from the occasional tumble, but more importantly it puts them on the stronger of the two stays. The chainstay is already pretty stout and doesn’t require a lot of added material to securely deal with the added braking forces. That leaves us free to keep the seatstay slender, save precious grams and maintain the intended ride quality.