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NinerAIR 9
Niner Air 9 RDO Mountain Bike Frame


Item # NNR006L

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Item # NNR006L

Bonafide rocketship for XC domination.

Destined for crushing miles of rolling singletrack and toeing the line on race day, the Niner 2018 Air 9 RDO Mountain Bike Frame delivers blistering acceleration and nimble handling for ripping across forest networks and blowing the doors off the competition. It's upgraded with Boost rear spacing and tweaked geometry for 2018, making it more capable at holding a line through rugged terrain without sacrificing its razor-like precision.

The most notable changes include a lower handlebar height, giving the Air 9 a nudge towards the venerable RKT 9 RDO's aggressive positioning. Paired with a longer cockpit and slacker head tube, this makes for a frame that handles deftly on knife-edge lines and jumps the second you need it to. Compared to the previous Air 9 the chainstays scrunched in by 4mm to 435mm for lightning fast acceleration and nimble handing without crossing over into jumpy, squirrely territory.

The new Air 9 RDO also sizes down its seatpost diameter to 27.2mm to take advantage of that little bit of extra flex and resulting comfort found in a narrower post. Out back, this year's model now boasts another different dimension; namely, a 12 x 148mm Boost axle width, keeping it in line with current trends for wider hubs and stiffer wheelsets. Niner also tucks the brake caliper mounts on the chainstay, neatly within the rear triangle. This makes sense from a frame building standpoint, as the seatstay is generally the burlier of the two rear stays and the placement protects the caliper somewhat in the event of a crash. We also think that particular placement just plain looks better than an ungainly bump hovering above a seatstay.

As with Niner's other RDO offerings, the Air 9 RDO is constructed using Niner's Carbon Compaction System (CCS), which gives Niner complete control over tube wall thickness across the frame. This makes for tube walls that are virtually perfect, reduces the amount of materials required, and eliminates excess resin build-up. The result is a claimed weight loss of 10%, which is a nearly unheard of leap between model years.

The Air 9 RDO’s large bottom bracket area provides stiff, efficient power transfer and sure handling, with the added bonus of versatility when choosing your bottom bracket. Opt for the standard PF30 on a geared setup, or swap it out for Niner's separately sold BioCentric 30 bottom bracket cups to go singlespeed or for compatibility with your favorite 24mm spindle cranks.

The 2017 Niner Air 9 RDO Mountain Bike Frame is designed to pair with a 100mm travel fork for race-worthy, aggressive positioning or a 120mm fork for more upright, all-day trail fun.

  • Blistering rocketship for XC racing and riding
  • Modern XC racing geometry with improved handling
  • RDO carbon frame is exceptionally light and stiff
  • 12 x 148mm Boost axle spacing for rear end stiffness
  • Optimized for 100mm forks, also works with 120mm forks
  • 27.2mm seatpost for greater compliance on bumpy trails
  • Di2-compatible internal cable routing makes it futureproof
  • Clears up to 2.4in tires for added traction, bump compliance

Tech Specs
Frame MaterialRDO carbon fiber
Wheel Size29in
Fork Travel[recommended] 100 - 120mm
Bottom Bracket Type73mm Press Fit 30 (Biocentric compatible)
ISCG Tabsno
Cable Routinginternal
Front Derailleur Mount34.9 high clamp
Derailleur Pullbottom, side
Seatpost Diameter27.2mm
Seat Collar31.8mm
Rear Axle12 x 148mm Boost
Recommended Usecross-country
Manufacturer Warranty5 years

100mm Travel Fork

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120mm Travel Fork

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Actual Weight


Actual weights are measured in-house by the Competitive Cyclist team.

Have questions? Chat with a Gearhead

What do you think about this product?



What is the max chainring for a 1x setup? and max rings for 2x setup?

Hey Jeffrey, The max chainring for a 1x setup is going to be 36T. For the max rings for a 2x set up, not entirely sure what the max will be but it is compatible with 2x and 3x systems.

>Rating: 4

Getting the Rudy

I've put it through the wringer
Size Bought
185 lbs

Between my wife and I we have owned about 10 Niners still own 5 loved the bikes but after a warranty problem I will never buy another. They have lost a good ninerd. Got the Rudy.

Curious, what was the warranty problem? Was the claim outside of the warranty window? Thanks for sharing.

>Rating: 5


I've used it once or twice and have initial impressions

Life has prevented me from getting lots of miles in on this bike, but so far I'm quite impressed. I have been pleased with how the bike handles, getting a few PR's on trails I've ridden a lot, despite getting out of shape over the winter. Bike weight with my "not a weight weenie" build is 18 lbs, 10 oz. Would not be hard to go sub 18 with this frame. I'm real exited to get to know this bike over the summer, then throw some 27.5+ wheels to carry the fun through the fall/winter.

Hi Travis, Just wondering if you've tried putting a 27.5+ tires on it? I'm really considering to get the bike as well, but I want the HT to be able to take 27.5+ 2.8inch tires as well.


Is this a tapered head tube?

Hi Luke, this is a tapered headtube and the frame includes a IS42/28.6 | IS52/40 headset which works with tapered suspension or rigid forks.


Hello, I was thinking of buying this frame and using a Lauf Trail Racer 29/27.5+ Boost Suspension Fork. Would this set up be compatible?

Hello Aidan, I have compared the axle to crown specs on a 100mm, 120mm Fox Factory 32 fork and the Lauf Trail Racer fork and I feel that the Trail Racer fork with an axle to crown length of 485 will be very comparable to a 100mm fork in a sag position. In short Yes it will be compatible with this frame.

>Rating: 5

snappy and light

I've put it through the wringer

Big fan of this frame. I've had one of these built up with XO1 Eagle out for demo for about a month now and I've really grown to appreciate the light weight, compliance, and snappy feel of this frame. For context, I've previously owned a few hardtails including an aluminum Scott Scale and steel Salsa El Mariachi. Unsurprisingly, I greatly prefer the way the Niner feels on the climbs - very efficient and tracks accurately through technical climbs - as well as the descents, where I can throw it around more playful than I'd anticipated. I'm 6'2.5" and have been riding a large. It fits decently but I would prefer it were an XL. I've been using an 120 mm fork which puts the HT angle at 69 degrees, which to me is an ideal balance between a planted, accurate feel on climbs and stability on higher-speed descents. If you want a super efficient hardtail that is light and reasonably playful for an XC bike, the Air is a great option.

Zach, I'm 6'2 and looking at the geo think I would lean towards the XL over Niner's suggested L for my size. What stem length and how many headset spacers are you runing?


Can this frame take a 27.5+ wheel/tire?

>Rating: 5

Light and Fast

I've put it through the wringer

Love it, great climbing machine and rides much softer than my Aluminum frame AIR 9. Have over 3,000 miles on this frame since I bought it and had it built up with some components from another bike and some new. Be sure you have a shop that knows about building Niner frames out since frame is best with 1X or 2X. I made the mistake of bringing over my existing 3X drive train and had some chain suck issues and ultimately had to do some minor repairs to the frame because of it. The pricing on this site beats NINER warranty pricing by a wide margin. I also purchased XT brakes and Industry Nine wheel set which gave me a tremendous upgrade to my WTB gear. One other warning which would have been handy to know is that Aluminum seat posts oxidize and freeze fast to the carbon frame which I am dealing with now. That is something that someone along the way should have mentioned.


Can this frame take a rigid fork or does it need a suspension fork? Thanks.

Hey Gregory! Thanks for the question! This frame can absolutely take a rigid fork, it is suggested to use the Niner specific fork for this frame though. Please give me a call or shoot an email over if you have any other questions! -Karissa 801-204-4567