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2018 Niner

SIR 9 2-STAR

A 27.5″ steel frame hardtail trail bike with high-end components.
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Manufacturer Price

$3,200
FrameSteel
SuspensionHardtail, 120mm
ForkFox Rhythm Float 34
Wheels27.5″
Drivetrain1 × 12
GroupsetGX Eagle, Truvativ Stylo
BrakesSRAM Guide R Hydraulic Disc
SeatpostDropper
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Gearing

A bike with lower gearing will be easier to ride up steep hills, while a higher top end means it will pedal faster down hills.

Lowest gear

(climbing)

26 mph

SIR 9 2-STAR

26 mph

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Highest gear

(descending)

Reviews

Summary

The Niner SIR 9 is a versatile cross-country bike praised for its durable Reynolds 853 steel frame, modern geometry, and ample bikepacking features. It offers a comfortable and stable ride, with handling that inspires confidence both uphill and downhill. The bike's compatibility with multiple wheel sizes and drivetrain options adds to its appeal for a wide range of riders.

Pros
  • Durable Reynolds 853 steel frame

  • Modern geometry for confident handling

  • Ample bikepacking features and mounting options

  • Compatible with multiple wheel sizes and drivetrains

  • Comfortable and stable ride quality

Cons
  • Initial feel of 27.5+ wheels as heavy and slow to accelerate

  • Requires adjustment period for those used to super-light 29er race bikes

  • 73mm PF30 BB shell requires adaptors for BSA type BBs

Key Quotes
A lively, modern geometry suited to challenging trails, both up and down.
BIKEPACKING.com
It’s a solid, well-built machine that really does make you feel like you can head out for days.
Mountain Flyer logoMountain Flyer
Niner’s new shred-ready hardtail can accommodate 29er or 27.5+ wheels.
MTBR logoMTBR

Feedback?

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Mountain Flyer
Tested: Niner SIR 9

Oct 2018

I have to admit — I am somewhat of a crusty old dude and sometimes resist change until it has been thoroughly tested by others. This being the case, I was a bit doubtful when I first climbed on the Niner SIR 9, a steel hardtail that can run 27.5-plus or 29-inch wheels. The 27.5x 2.80 tires seemed like overkill compared to my super-light 29er race bike, and the thought of riding a bike that wasn’t fully suspended had me questioning my sanity.

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BIKEPACKING.com
Niner SIR 9 Review, Tested on the Colorado Trail

Oct 2017 · Cass Gilbert

Like steel hardtails? We test the Niner SIR 9, boasting a modern, slack geometry, room for 27.5+ tires, and a host of bikepacking-friendly details.

Lows
  • Although its gear range is excellent, SRAM XO1 Eagle feels built for racing rather than bikepacking. It’s fiddly to set up and sensitive to cable stretch.

  • Press fit bottom bracket requires specialist tools that may be hard to find in the backcountry.

  • While an eccentric insert is available, none of the standard builds include it.

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BIKE Magazine
Niner Updates the SIR 9

Jun 2017

The Niner SIR 9 gets the longer, lower, slacker treatment

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MTBR
Niner SIR 9 trail bike launched

Jun 2017 · Mtbr

News out of the Niner camp today. The Colorado-based bike maker has re-released its original steel classic, the SIR 9, in a redesigned, ready for anything form. - Mtbr.com

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Geometry
Specs
Build
Frame

SIR 9 - SLATE BLUE/ORANGE

BB StandardPF30, Press Fit

Tire Clearance2.4"

Fork

FOX 34 FLOAT RHYTHM GRIP EVOL, SWEEP ADJUST, 120MM, 110X15MM

Travel120mm

Spring TypeAir

Shock

N/A

Bottom Bracket

SRAM%20PF30

Headset

NINER INTERNAL ZS SHIS DESCRIPTION ZS44/28.6|ZS56/40

Stem

RACE FACE AEFFECT R 50MM, 35MM CLAMP

Handlebar

RACE FACE AEFFECT R 780MM WIDE, 20MM RISE, 35MM CLAMP

Saddle

NINER CUSTOM TR WITH CR-MO RAILS, PRINTED NINER GRAPHIC

Seatpost

KS LEV SI

TypeDropper

Grips

NINER GRRRIPS L/O NYLON FLANGED

Groupset
Crank

SRAM STYLO 7K EAGLE PF30 32T

Shifters

SRAM GX EAGLE 12SP

Cassette

SRAM EAGLE XG 1275, 10-50T

Chain

SRAM GX EAGLE 12SP

Brakes

SRAM GUIDE R

TypeSRAM Guide R Hydraulic Disc

Brake Levers

SRAM GUIDE R

Wheels
Tires

29" MAXXIS ARDENT F60 SC 2.4 or 27.5+ MAXXIS REKON+ DC/EXO/TR 2.8

Rider Notes
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First added March 30

Last updated March 30

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