Niner 2021 SIR 9 2-STAR Hardtail Mountain Bike (Cement/Black/Copper)

Price: $2,550.00
Discontinued Online
This item is discontinued and no longer available for purchase. You may want to search our site for a similar item.

There’s a new bike in town and it’s built to last, not let you down. When you’re spinning up steep climbs, bombing down the backcountry and grinding out the final miles as the sun sinks into the horizon, you need a bike you can trust. A comfortable, capable, hand-built bike made from proven, air-hardened, heat-treated steel. That’s right, steel. Because Steel Is Real and it’s fully optimized in the SIR 9.

The classic steel frame construction gives you the comfortable, durable, capable, "ride hard, put away wet" mentality that you have always wanted in a frame. No fewer than 18 threaded mounting bosses for racks, fenders, frame bags, bottles, and even a top-tube bento box. "Trail country" geometry delivers optimum performance on long pedaling rides, stiff climbs, extended descents, and spicy technical sections. With clearance for up to 29 x 2.4' tires or 27.5 x 3.0, you can go farther and stay out longer.

SRAM does it again with this 2-Star SX Eagle parts kit. It's a wallet friendly, yet high-performing parts kit. Mated to the SIR 9 frame and Marzocchi suspension, every feature of this adventure-seeking singletrack slayer is fully optimized.


  • Reynolds 853 steel frame construction because "steel is real"
  • 2-Star SRAM SX Eagle components
  • No fewer than 18 mounting bosses for bags, racks, bottles, and more
  • Niner alloy wheels, 30mm internal width
  • Marzocchi Bomber Z2 rail suspension fork, 120mm travel
  • Biocentric 30 bottom bracket gives you the freedom to run whatever drivetrain you desire
  • Trail ready geometry provides a longer top tube and slacker head tube for more stability at speed
  • Integrated dropper post routing for a clean setup
  • Tire clearance for up to 29 x 2.4" or 27.5+ tires
  • Niner Alloy seatpost

Due to availability issues during manufacturing, build specifications are subject to change. Please contact us if you wish to verify build specs before purchase.

Colors: Cement Grey/Black
Frame: Hand Welded Reynolds 853 Steel; External Cable Routing; Integrated Bottle, Bag, Rack And Fender Mounts; 12 x 148mm Thru Axle
Fork: Marzocchi Bomber Z2 Rail, Sweep Adj, 120mm, 110 x 15mm, 44mm Offset
Shock: N/A
Tubes / Sealant: Stans No Tubes Sealant (2 x 2oz Bottles)
Front Wheel: Niner Alloy, 30mm Internal Width, 110 x 15mm
Rear Wheel: Niner Alloy, 30mm Internal Width, 148 x 12mm
Front Tire: Schwalbe Nobby Nic EVO Super Trail TLE Addix SpeedGrip 2.6"
Rear Tire: Schwalbe Nobby Nic EVO Super Trail TLE Addix SpeedGrip 2.35"
Brakes: SRAM Level
Brake Levers: SRAM Level
Brake Rotors: SRAM Level
Chain: SRAM SX Eagle 12 Speed
Front Shifter: N/A
Rear Shifter: SRAM SX Eagle 12 Speed
Front Derailleur: N/A
Rear Derailleur: SRAM SX Eagle 12 Speed
Cassette: SRAM PG 1210 11-50T
Crankset: SRAM 1x 1K Eagle DUB, 32T
Bottom Bracket: SRAM DUB PF30
Saddle: Niner Custom TR w/ Chromoly Rails, Embossed Niner Graphic
Seatpost: Niner Alloy, 370mm
Handlebar: Race Face Aeffect R 780mm Wide, 20mm Rise, 35mm Clamp
Stem: Race Face Aeffect R 40mm, 35mm Clamp
Headset: Niner Internal ZS SHIS ZS44/28.6 | ZS56/40
Grips: Niner Grrrips Lock-On Nylon Soft Compound
Approximate Weight: 28.8 lbs

Frame Mounts And Fittings: 2 Inner Triangle Bottle Mounts, 1 Mount Under Down Tube, 1 On Top Tube, Rack And Fender Mounts.
Rear Suspension Travel: N/A
Maximum Front Suspension: 120mm
Fork Offset: 44mm
Shock Size: N/A
Shock Mounting Hardware: N/A
Suggested Shock Sag: N/A
Seatpost Size: 30.9mm
Seat Collar Size: 34.9mm
Cable Routing: External
Front Derailleur Type: 34.9mm Clamp Side Swing, Front Pull
Pivot Bearing Specs: N/A
Chainring Compatibility: Compatible With Standard 1x, 2x, & 3x Systems
Maximum Chainring Size: 1x Max Chain Ring Size: 36T - Boost Chainring Recommended
Q-Factor: 168mm
ISCG Compatibility: No
Bottom Bracket Type: 73mm PF30 BB Shell (Adapters Required For BSA Type BBs); Compatible w/ Biocentric 30 BB
Brake Mount Type: Post Mount
Maximum Rear Rotor Size: 180mm
Rear Wheel Spacing: Boost 12 x 148mm
Rear Wheel Through-Axle Spec: M12 x 1.75P x 182L
Front Wheel Axle Spacing: Boost 15 x 110mm
Front Wheel Through-Axle Spec: -
Max Tire Size: 29 x 2.35" or 27.5 x 3.0" Tire (Tire Sizes Vary By Brand, Some Tires May Not Fit)

This product was added to our catalog on April 27, 2021

Sizing Recommendations for Riders Who Fall Between Sizes:

  • Sizing down will provide a more maneuverable ride while sizing up will provide more stability
Rider Height (Feet)Rider Height (Meters)
XS5' - 5'5"1.53 - 1.65m
S5'3" - 5'9"1.6 - 1.75m
M5'8" - 6'1.73 - 1.83m
L5'11" - 6'3"1.8 - 1.91m
XL6'3" - 6'7"1.91 - 2.01m

Note: All sizing recommendations are provided by the manufacturer and may differ for each rider.


Fork Travel120mm120mm120mm120mm
(A) Top Tube Length595mm603mm627mm652mm
(B) Seat Tube Length396mm421mm485mm533mm
(C) Chainstay Length Actual430mm430mm430mm430mm
(D) Horizontal Chainstay427mm427mm427mm427mm
(E) Front Center693mm711mm737mm764mm
(F) Wheelbase1118mm1136mm1162mm1189mm
(G) Bottom Bracket Drop52mm52mm52mm52mm
(H) Headtube Length100mm110mm125mm145mm
(I) Headtube Angle68.0°68.0°68.0°68.0°
(J) Seat Tube Angle74.0°74.0°74.0°74.0°
(K) Standover Height721mm739mm791mm830mm
(L) Reach410mm425mm445mm465mm
(M) Stack611mm620mm634mm652mm
Fork Travel120mm120mm120mm120mm
(A) Top Tube Length23.4"23.7"24.7"25.7"
(B) Seat Tube Length15.6"16.6"19.1"21"
(C) Chainstay Length Actual16.9"16.9"16.9"16.9"
(D) Horizontal Chainstay16.8"16.8"16.8"16.8"
(E) Front Center27.3"28"29"30.1"
(F) Wheelbase44"44.7"45.7"46.8"
(G) Bottom Bracket Drop2"2"2"2"
(H) Headtube Length3.9"4.3"4.9"5.7"
(I) Headtube Angle68.0°68.0°68.0°68.0°
(J) Seat Tube Angle74.0°74.0°74.0°74.0°
(K) Standover Height28.4"29.1"31.1"32.7"
(L) Reach16.1"16.7"17.5"18.3"
(M) Stack24"24.4"24.9"25.7"