Use Code MEMORIALDAY20 for 20% Off One Full-Price Item

Detail Images

  • Niner - Bottom Bracket
  • Niner - Logo
  • Niner - Bottom Bracket
  • Niner - Bottom Bracket
  • Niner - Seat Tube
  • Niner - Top Tube
  • Niner - Side
  • Niner - Rear Brake Mount
  • Niner - Detail
  • Niner - 3/4 Front
  • Niner - 3/4 Back
  • Niner - Dropout
  • Niner - Chain Stays
  • Niner - Air 9 RDO Mountain Bike Frame - 2018 - CMYK
  • Niner - Bottom Bracket  -
  • Niner - Logo -
  • Niner - Bottom Bracket  -
  • Niner - Bottom Bracket  -
  • Niner - Seat Tube -
  • Niner - Top Tube -
  • Niner - Side -
  • Niner - Rear Brake Mount -
  • Niner - Detail -
  • Niner - 3/4 Front -
  • Niner - 3/4 Back -
  • Niner - Dropout -
  • Niner - Chain Stays -

Current Color

  • Niner - Air 9 RDO Mountain Bike Frame - 2018 - CMYK

Niner Air 9 RDO Mountain Bike Frame - 2018


Free 2-Day shipping on orders over $50. Learn More

Select a Size:

Find your size

Note: Actual inseam is not the same as pant inseam.How to measure

Recommended Size

We recommend a size in this bike.

EditMore details

Our size calculator is a starting point for finding the right size for you. To get personal advice talk to one of our fit experts at 1.888.276.7130 or chat now

Select options
  • Select options
    • S
    • M
    • L

    Select a Color:

    Select options
  • Select options
    • CMYK

    4 Reviews


    Get some fresh Air.

    The improved geometry of the 2017 Air 9 RDO Mountain Bike Frame is a testament to Niner’s unrelenting drive to refine the company’s crown jewel of hardtail racing. The Air 9 offers a more aggressive race fit with a lower handlebar height, and the extended cockpit and tapered headtube deliver a nimble frame with precise handling. The Air 9 also delivers the stiffness of a PF30 bottom bracket, and the 148mm Boosted rear axle spacing provides added stability and improved performance with today’s wider rims and beefier tires. To give you a more comfortable ride, Niner downsized the seatpost to a more forgiving 27.2mm. Most importantly, the Air 9 RDO is constructed with Niner’s Carbon Compaction System, which reduces excess resin build-up, allowing Niner to use less material and control the thickness of the tube wall across the frame me with the utmost precision. The result is a considerably lighter frame that is stronger and more durable.

    • Item #NNR004X

    Tech Specs

    Frame Material
    carbon fiber
    Wheel Size
    29 in
    Fork Travel
    [recommended] 100 - 120 mm
    Head Tube Diameter
    1-1/2 to 1-1/8in tapered
    Headset Included
    yes, Cane Creek 40
    Bottom Bracket Type
    73 mm PressFit 30
    ISCG Tabs
    Cable Routing
    Front Derailleur Mount
    34.9 high clamp
    Derailleur Pull
    bottom, side
    Brake Type
    Seatpost Diameter
    27.2 mm
    Seat Collar
    31.8 mm
    Rear Axle
    12 x 148mm Boost
    Recommended Use
    cross country
    Manufacturer Warranty
    5 years

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    First time on Niner and NEVER AGAIN!

    • Familiarity: I've put it through the wringer

    Long time racer / rider. Frame cracked at the seat post clamp. After paying to have it warrantied ($75 each way) the second frame cracked in the same spot. Niner is not good about warranties and not good with quality control.

    Smooth rider

    • Familiarity: I've used it several times

    I picked up this bike a few weeks ago and was finally able to hit the trails yesterday, and all I can say is wow! The Fox Float fork, Niner carbon wheels and Sram X01 Eagle performed flaslessly.

    I have not ridden a hardtail in years, and this bike blew me away at how well it handled rough terrain. The bike was stable on the steepest of descents and climbed like a goat.

    I'd be happy to assist you with your custom build or answer any questions you may have.


    Smooth rider

    Dangerously Fast

    • Familiarity: I've put it through the wringer

    Replaced a 9 year old Air 9 Aluminum. Upgraded to RDO, Industry Nine wheel set and XT brakes. This frame is great for climbing and if you are coming from aluminum it rides softer and holds a line better on the downhill. I love it.
    Just wish Niner had included a chain suck guard. Seems cheap of them not to.

    New and Improved!

      One of my favorite hardtails we offer. The new version of this bike features boost spacing making the bike very laterally stiff which equates to incredible power transfers. Its a very fast and efficient ride and highly recommended!
      If you need help configuring this frame or have quesions with it or the new boost spacing feel free to reach out to me direct.
      Wes Branham- Account Manager -Bike

      I will check with Niner on the frame weight for you. We can spec the bike with a 100mm fork as well. Send me an email on how you would want the bike spec'd and I will shoot you over a quote.

      Does anyone know the max 27.5 tire size that will fit on this frame?

      Hey Justin,

      Niner does not put a max tire width spec on this bike. On their regular builds they have their Niner Carbon XC wheels which have a 24mm internal width with a 2.2 inch Maxxis Ikon on the rear. That will give you a good starting point, If you want to reach out to me, I can contact Niner directly to give you a full answer.

      You can reach me at

      what is the weight in grams of the Air 9 RDO frame? (Why is it not posted if it's so light?)

      Hey Matthew - These Air 9 RDO frames weigh approximately 1,050 grams with hardware (seat collar and derailleur hanger, plus paint and protective tape). Feel free to contact me directly with any additional questions, especially if you are interested in ordering this frame or building a complete bike.

      - Kyle L. - Expert Gearhead - - 801-736-4337