Niner ROS 9 review

Leftfield steel trail slayer

Our rating 
5.0 out of 5 star rating 5.0
GBP £900.00 RRP

Our review

Pricey, but an intoxicating and addictive blend of enduro attitude, steel smoothness and build quality
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A steel frame at this price might seem outrageous, but we’d open our wallets without hesitation for Niner’s unbelievably smooth yet full-gas, grinfest-fast trail terror.

  • Highs: Genuinely floats like a butterfly but stings like a whole damn hive
  • Lows: Expensive, heavy and not as rigidly accurate as some bikes
  • Buy If: You can afford a sublime mix of trail melting steel alchemy and bomber belligerence

Frame and equipment: a beauty

Part of the price justification comes from some truly beautiful bits of workmanship on the ROS 9. The custom double-butted main tubes are subtly curved to manipulate ride character while the seat tube curves back over the wheel from the adjustable Biocentric II eccentric bottom bracket block.

The double-butted (with identical wall thickness) and gusseted top and down tube are strong enough to handle up to a 140mm fork:
Russell Burton

The double-butted (with identical wall thickness) and gusseted top and down tube are strong enough to handle up to a 140mm fork

A machined chainstay yoke still means tons of clearance and stealth dropper post routing, optional front derailleur hanger, 140mm tapered fork capability and 142x12mm axle boxes are all ticked.

Ride and handling: a beast

What would make us buy a frame that costs this much, however, has little to do with features and cosmetics – it’s the ride. Thanks to what we can only describe as chromoly steel alchemy the rear stays give an incredibly – in the true sense – supple and smooth ride. In fact traction and ground connection are more like a short-travel suspension frame in ‘pedal’ mode than a hardtail. We lost count of the number of times we checked the Maxxis CrossMark rubber under our back end because we presumed it was punctured but no, it really does melt the trail and glue the tread to the ground.

RockShox’ revelation fork twinned with a 67-degree head angle means you can go barrelling into dicey corners and emerge unscathed:
Russell Burton

RockShox’ Revelation fork is twinned with a 67-degree head angle

That crazy level of traction and go-with-the-flow smoothness is the same at the end of the Revelation fork too. Add a super-slack 67-degree head angle and potentially belly scraping centre of gravity and you can pile the ROS 9 into sketchy corners or straight line rocky, rooty carnage like a fully-sprung enduro bike and come out still inflated and elated.

Despite the impact shrugging insolence it still instinctively puts the front end exactly where it needs to go. As the front end grabs grip it then chops or slides the short back end through to exit way tighter and faster than you’d believe. The tight rear lets it pop the front wheel up without hesitation whether you’re sending a drop or manualling a treacherous wet root spread. The only time it gets caught out is trying to sneak it down super-steep switchbacks where the front end can be too long and not quite stiff enough to get round every time. Somehow there’s no obvious softness or spongy loss of pedal power though.

The ros 9’s ride is incredibly supple, smooth and planted:
Russell Burton

The ROS 9’s ride is incredibly supple, smooth and planted

As a fairly hefty machine we’re not saying this is a fire road climb dragster, but it holds its own surprisingly well on more techy climbs. In fact, the fluid rear end and unholy grip saw us first-time clean and then nonchalantly multi-repeat a super-ugly stepped climb we’ve been trying to bag for 20 years. While the Niner bars and stem are spot on and the SRAM X01 11-speed kit is perfect for the ROS 9, it rides this well with distinctly ordinary WTB wheels – so an upgrade to a proper pair of premium hoops is likely to unleash even more superlative adulation.

Specifications as tested:

  • Size Tested: M (also available S, M, L, XL)
  • Weight Tested: 12.95kg / 28.54lb
  • Frame: Niner custom butted chromoly
  • Fork: RockShox Revelation RCT3, 130mm
  • Shock: N/A
  • Max Tyre Size: 2.4in


  • Chainset: SRAM X01, 34T
  • Shifters: SRAM X01
  • Derailleurs: SRAM X01 (R)
  • Chain: SRAM XX1
  • Bottom Bracket: SRAM X01
  • Cassette: SRAM X01, 10-42T


  • Front: WTB i19 TCS rim, Hope Pro 2 Evo hub
  • Rear: WTB i19 TCS rim, Hope Pro 2 Evo hub
  • Tyres: Maxxis High Roller, 29×2.3in (F), Maxxis CrossMark, 29×2.2in (R)


  • Brakes: Shimano XT, 180/160mm rotors
  • Bars: Niner alloy, 780mm
  • Stem: Niner RDO, 70mm
  • Grips: Hope, lock-on
  • Seatpost: KS Lev Integra
  • Saddle: WTB Volt Race
  • Headset: Hope
  • Pedals: N/A

Product Specifications


Name ROS 9 (15)
Brand Niner

Description Hardtail Frame - Niner custom butted chromoly
Seat Tube Angle 73
Head Tube Angle 67
Top Tube (in) 23.54
Top Tube (cm) 598
Seat Tube (in) 16.97
Seat Tube (cm) 431
Chainstays (cm) 428
Chainstays (in) 16.85
Wheelbase (in) 44.21
Wheelbase (cm) 1123
Bottom Bracket Height (cm) 310
Bottom Bracket Height (in) 12.2
Standover Height (cm) 733
Standover Height (in) 28.86