Take yer pick.

The new Niner AIR 9 sees the bike grow longer and accept fatter tyres. An interesting mix of evolution and revolution from the cult US brand.

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2018 Niner AIR 9 need to know

niner air 9

Niner recently revamped its full suspension range to bring it up to speed with the plethora of new standards that have swamped the mountain bike world in the past couple of years.

With the new AIR 9 it’s also now doing the same revamping of its hardtail range. As well as the geometry getting a bit of an overhaul, the frame is now Boost 148 at the back and there’s also the ability to run 27.5+ tyres in there as well as Niner’s usual eponymous 29er hoops.

niner air 9

Niner’s own description is apt: “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.”

niner air 9

The new geometry isn’t massively slacker but it’s significantly longer in reach and shorter at the back than previous AIR 9 bikes. The fork travel is also now based around a longer 120mm fork – which is what most AIR 9 owners ran anyway – and we dare say you could run 130-140mm forks up front without issue so long as they’re setup suitably (lots of sag and firmly damped).

niner air 9

The head angle is not placed at a rather conservative-for-2018 68°. The target market of the AIR 9 is after all riders at the XC end of the trail riding spectrum who may not willing/able to adapt to the Brave New World of slacker-lower-longer geometry, or they’re just not sold on the idea either.

There’s provision for a front mech on there for all you Di2-ing Double chainringers out there. There are also two sets of bottle bosses on all but the small and extra-small size frames.

niner air 9

The BB is a Pressfit PF30 affair – shock horror – but this does afford the ability to run threaded aftermarket cups if you wish to or run an eccentric BB if you want to run singlespeed or hub-gear setups.

The reach numbers have up; 425mm for a medium, 445mm for a large, so nothing crazy but it will definitely handle differently than earlier AIR 9s. A relatively whopping 12mm has been hacked off the chainstay length – that’ll be the Boost 148 effect then – with the new AIR 9’s ‘stays being 427mm.

Speaking of back ends, the new Niner AIR 9 isn’t skimping or squeezing in the rubber. You can comfortably run 29 x 2.4in tyres or full-on Plus 27.5 x 3.0in tyres in there.