Niner Bikes Updates New AIR 9 With 27.5+ Compatibility

Niner Bikes has been rolling through several key updates across it’s entire mountain bike lineup, including the move to Boost hub spacing, a wholesale rework of frame geometry, and the option to run 29in or 27.5+ wheels and tyres. It’s rolled out these changes with full suspension models like the JET 9 and RIP 9, and now it’s doing the same with its hardtail range too.

Hot on the heels of the release of the steel SIR 9 hardtail, the latest AIR 9 encompasses many of the same updates, but encompassed in a lighter and stiffer hydroformed alloy frame. Also built around a 120mm travel fork and a versatile PF30 bottom bracket shell, the new AIR 9 looks to offer a ‘cross country plus’ vibe with plenty of different setup options.

The new AIR 9 from Niner Bikes offers 27.5+ compatibility for those like a little more cushion.

“If a cross country bike met a trail bike out in the woods, they fell in love and had a child, what would that bike be? How about Niner’s new AIR 9? The perfect blend of cross country quickness, mixed with a rowdier attitude. Run it geared. Run it singlespeed. Comfortable enough for all day riding and quick enough to pin it at the races, the new AIR 9 handles what you throw at it. Genetically engineered? Maybe not. But it sure is fun to ride” – From Niner Bikes.

Regardless of wheel setup, the AIR 9 is built around a 120mm travel fork and new geometry that goes longer up front, and shorter out back.

Niner AIR 9 Features

Hydroformed alloy frame
Compatible with 29in and 27.5+ wheelsizes
Max tyre clearance: 29×2.4in or 27.5×3.0in
Tapered zero-stack head tube
Designed for 120mm travel forks
68° head angle
74° seat tube angle
427mm chainstay length
148x12mm Boost rear spacing
73mm PF30 BB shell
Setup geared or singlespeed with the Niner Biocentric 30 bottom bracket (included)
Compatible with 1x and 2x drivetrains
Sizes: X-Small, Small, Medium, Large, X-Large

Niner AIR 9 frame geometry.

Geometry mirrors the latest steel SIR 9, which means the AIR 9 also slackens out to a 68° head angle, and also increases the front centre length across the board. That means you’re looking at a reach measurement of 425mm for a Medium, and 445mm for a Large. Also noteworthy is the 427mm chainstay length, which shortens down from the previous AIR 9 alloy frame’s 439mm chainstay length. Impressive given that the new AIR 9 will fit up to a 29×2.4in wide tyre, or in plus setup, a 27.5×3.0in wide tyre.

The new AIR 9 shortens the chainstay length to just 427mm, while offering tyre clearance for 29×2.4in or 27.5×3.0in wide rubber.

The AIR 9 is now built around a 120mm travel fork and features longer and slacker geometry for a more trail-friendly vibe.

Each frame size is optimised around using a 50mm stem and 780mm wide handlebars.

Niner’s 73mm wide PF30 shell can take a PF30 or threaded BB. And with the eccentric BioCentric II cups, it can also provide a singlespeed setup.

Also available as a frame on its own to build it up as you like. The frame is front derailleur compatible, and there are two water bottle mounts inside the front triangle on the Medium and above frame sizes.

Just like the SIR 9, only more aluminum.

To get further information on the new AIR 9, get all the details you need directly from the Niner Bikes website.

David Hayward

David started mountain biking in the 90’s, by which he means “Ineptly jumping a Saracen Kili Racer off anything available in a nearby industrial estate”. After growing up and living in some extremely flat places, David moved to Yorkshire specifically for the mountain biking. This felt like a horrible mistake at first, because the hills are so steep, but you get used to them pretty quickly. Previously, David trifled with road and BMX, but mountain bikes always won. He’s most at peace battering down a rough trail, quietly fixing everything that does to a bike, or trying to figure out if that one click of compression damping has made things marginally better or worse. The inept jumping continues to this day.