Niner Jet 9 Carbon XT XC Fox – first ride review

Quick-witted singletracker

Our rating 
3.5 out of 5 star rating 3.5
GBP £4,949.00 RRP | USD $4,999.99

Our review

Positive-pedalling XC cruiser with fantastic appeal, but design niggles for more aggressive riders
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Having nailed their eponymous colours very firmly to the 29er flagpole early on, Niner can justifiably feel smug – big wheels are the way to go for increased cross-country speed, distance and control, as everything from racing to the hordes of new bikes have shown. But can the latest carbon incarnation of their long running, short-travel bike compete now the bigger brands are well in on the action?  


Niner have built their business on being different, and the Jet 9 Carbon stands out in a 29er-packed landscape – it’s a natural climber, and a quick-witted singletracker with tons of boutique identity. It’s more at home cruising rolling hills than carving berms and blasting over boulders though, so look elsewhere in the range if that’s what you’re after.

Ride & handling: Sharp, super-old-school XC climber

Niner put a lot of emphasis on the claim that their Continually Variable Arc (CVA, initialism fans) suspension is designed to pedal really well with any size chainring. We’ve tried the system with both triple and double chainrings, and can confirm that it’s much more stable and less stabby in smaller rings than competing twin-link setups, such as Santa Cruz’s VPP. That means you can leave the Jet 9’s Fox CTD shock in the smoothest (Descend) setting more often than normal, only flicking over to the extra low-speed compression of Trail when really punching power through the pedals.

Your feet sit very high compared to most 29ers we’ve ridden (the bottom bracket is a full 20mm higher than a Santa Cruz Tallboy’s, for example), which means no worries at all about crank contact on rough ground and constant, uninterrupted power even when lurching up over logs and boulders.

A steep seat angle with minimal layback on the two-bolt carbon post, plus an equally steep head angle, puts rider weight forward into an ideally poised climbing position. The quick and responsive steering – matched to long chainstays – keeps it accurately on track even up the narrowest, sketchiest lines, and the Jet 9 nonchalantly cleaned several technical test climbs we haven’t managed in ages. The low-curved top tube means we never got neutered when we did screw up and stall either.

The tall bottom bracket can feel precarious when you’re scuffing around on loose surfaces:
Russell Burton

The tall bottom bracket gives plenty of crank clearance but can feel precarious when you’re scuffing around on loose surfaces

The same fast-steering, high-clearance character works well on slow singletrack, where it nips round tight turns with noticeably less bus-like manners than most 29ers. The neutral CVA design tracks the ground well for traction, proving it’s not just about pedalling efficiency, although it slaps into bigger blocks and drops rather than soaking them up smoothly.

The Jet 9 Carbon geometry flies in the face of the current trend for low, slack-angled frames, even for this short-travel category. The tall bottom bracket can feel precarious when you’re scuffing around on loose surfaces, and having the front wheel tucked in underneath you can make the Niner shake and shimmy when you’re hard  on the brakes or getting bullied by big rocks. The frame is cleared for a 120mm fork, which slackens the angles by a degree, but raises the bottom bracket even higher – we’d stick at 100mm, enjoy the clear climbing advantages and avoid a high-heeled compromise.

The stiffness of the large main tubes is undermined by the down tube and seat tube both shrinking (for linkage and front mech clearance, respectively) before they get to the bottom bracket. This leaves power response adequate rather than amazing, and the heavy, fully-tubeless tyres of this build kit dull the dynamics. Open dropouts for a quick-release axle undermine those big rear stays and the voluptuous post-mount section of the asymmetric rear end. The Jet 9 misses the 142x12mm screw-through setup of its RDO (Race Day Only) sibling.

There are other niggles. Climb-honed calves are likely to rub on the outside edge-routed rear brake hose, which is an irritating practical oversight considering how refined the cosmetics are. The internally routed gear cables really slap and rattle inside the flat-faced down tube too, although that’s hopefully solvable with a liner sheath. It’s also undeniably expensive, although the price of frame kits and complete bike options are comparable with other boutique carbon machines.

Internally routed cables are a letdown as they rattle inside the flat-faced down tube:
Russell Burton

Internally routed cables are a letdown as they rattle inside the flat-faced down tube

Frame & equipment: Good-looking build that stands out from the 29er crowd

Niner have an edge when it comes to distinctive identity. Whether it’s their impressive collection of logos, the swagger of their ‘Pedal, damn it’ slogan, their vibrant online community or the way their seductive machines look particularly gorgeous in promo pics, they teach the rest of the industry how it’s done.

Despite being £600 cheaper than the flagship Jet 9 RDO (which gets two-tone paint, carbon linkages, Enduro bearings and a 142x12mm rear axle) the detailing of the Jet 9 Carbon is still impressive. This includes red-anodised pivot caps, a headbadge with internal cable inserts, forged linkages with logos machined into them and a nice bolted seatclamp. 

The colour-coded Niner RDO carbon finishing kit is top quality gear (the bars are £179 separately, the post £190) and the top cap is even designed so you can re-crimp your favourite beer bottle cap onto it. Perfect. None of these cosmetic details affects the way the bike rides but, as with the finest Swiss watches, when things are done this well it creates a truly aspirational appeal – and helps justify  the premium cost. Happily for both us and the Jet 9, those bejewelled and flowing lines conspire to create a sparkling, flowing ride as well. 

Niner also buck the big-wheels-aren’t-for-little-riders trend by producing the Jet 9 in an extra small frame with an impressively low 672mm (26.4in) standover. If you like the sound of the high-riding, climb-friendly geometry but your budget is lower, the 80mm travel alloy Jet 9 is £600 cheaper at £1699 for the frame only.

Great looks won’t make you ride any faster, but help ease the pain of the pricetag:
Russell Burton

Great looks won’t make you ride any faster, but they do help ease the pain of the pricetag


This article was originally published in What Mountain Bike magazine, available on Apple Newsstand and Zinio.

Product Specifications


Name Jet 9 Carbon XT XC (13)
Brand Niner

Description XS, S, M (tested), L, XL
Stem Niner alloy
Front Wheel WTB Frequency Team i19 TCS rims, Hope Pro2 Evo Niner etched hubs
Tyres Maxxis Ardent LUST tubeless, 29x2.1in
Wheelbase (in) 43.9
Top Tube (in) 23.4
Seat Tube (in) 18
Chainstays (in) 17.9
Bottom Bracket Height (in) 13.6
Weight (lb) 26.72
Weight (kg) 12.12
Seatpost Niner Flat Top RDO carbon
Brakes Shimano M785 XT
Seat Angle 74
Saddle WTB Silverado Team
Rear Shock Fox Float CTD Evolution, 100mm
Rear Derailleur Shimano M780 XT
Head Angle 71.5
Handlebar Niner Flat Top RDO carbon
Front Derailleur Shimano M780 XT
Frame Material Niner monocoque carbon fibre
Fork Fox F29 Float CTD Evolution, 100mm
Cranks Shimano M785 XT, 26/38T
Rear Wheel WTB Frequency Team i19 TCS rims, Hope Pro2 Evo Niner etched hubs