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Niner Sir 9 2 Star SS Bike

Item #: BI226A04
Availability Please make a selection
Quantity   Out of stock.
Untitled Document

Note: Photos are for illustration purposes. You will be shipped a complete bike with the specifications listed below.

Niner SIR 9 2 Star Single Speed Bike

The Niner SIR 9 demonstrates steel is real! Steel bikes are as relevant today as they were 50 years ago. With that said, all steel is NOT created equal. The Niner SIR tubing is a custom selected set that utilizes the best tube options for each application within the frame. The front triangle is comprised of new Reynolds 853 DZB (Double Zone Butting) tubing. Developed for mountain bikes, more specifically 29ers, Reynolds 853 DZB offers two significant advantages. Historically downtube fork clearance on 29ers has been tricky because of the relatively high head tube to bottom bracket height. A straight downtube needs to be welded high on the back of the headtube to achieve fork clearance, often requiring either a gusset between the headtube and the downtube or a thicker heavier downtube to achieve the desired strength. The Reynolds 853 DZB tube overcomes this limitation by incorporating two different butting profiles on the same downtube. The superior strength is combined with a butting profile in the rest of the tube that maintains ride quality, and keeps the weight down. Secondly, the 853 DBZ tube is the proprietary bend. Niner worked with Reynolds to shape the tube for the SIR 9 so the tube can attach lower on the headtube, which reduces front end torsional flex, and increases steering precision, while adding strength.

Like the rest of Niner's bikes, the SIR 9 utilizes Niner's tried and true geometry. There are plenty of nifty features that you’ll find in the SIR 9. The Niner SIR 9 features the BioCentric bottom bracket system. The BioCentric makes adjustment easy across a wide range of gears and eliminates the need for adjustable dropouts, giving the cleanest possible solution for singlespeed use. The BioCentric offsets the bottom bracket spindle 8.5mm from center, offering greater range of adjustment compared to a more traditional EBB setup. Conventional EBB units mounted with set screws that can become tricky to finely adjust over time, or expansion wedges that can warp the bottom bracket shell of the frame, while split BB shells that clamp an EBB can stretch or ovalize. The BioCentric II shuns these quandaries by using two bolts to apply a clamping force on the outside edges of the BB shell, eliminating the likelihood of ovalizing or indexing the shell itself. The BioCentric II will certainly have you seeing singlespeed living in a whole new light.

Highlighting the Niner SIR 9 2 Star Single Speed build is Niner’s Cogalicious Single Speed Cog. Constructed from 7075 T-C aluminum, the Cogalicious reflects Niner’s dedication to bring quality to those who are seduced by the suffering that comes from having but only one gear. The Cogalicious is slightly offset so you can fine tune your chainline by flipping the cog, while the thick offset base prevents the damage of alloy freehub bodies under heavy loads. The Truvativ AKA cranks feature OCT hollow forged arms, keeping weight to a bear minimum without sacrificing strength and stiffness. Speaking of stiffness, The Niner RDO rigid carbon fork mates perfectly with Rock Shox’s 15mm Maxle for race-dominating power transfer and vibration dampening. Stan’s No Tubes and Schwalbe combine forces to offer a tubeless wheel set up that can corner, accelerate and climb. SRAM Elixir 5 brakes and brake levers inspire confidence in your braking to keep you descending like a sinned soul. Niner components rounds out the cockpit with a carbon seatpost and an alloy bar and stem. Not to mention, the ultra flashy head badge and dazzling paint is enough to make you swoon.

2014 Niner SIR 9 Frame Features

  • 73mm BB width (with BioCentric installed)
  • BioCentric is compatible with external bearing cranksets only
  • 27.2mm seat post size, 400mm length recommended
  • 28.6mm front derailleur, high mount, bottom pull
  • 29.6mm seat collar size
  • Tapered headset with internal (ZS) top cup and 1.5" external bottom cup. Cane Creek standard description: ZS44/28.6 | EC44/40
  • Small frame has one bottle mount inside the front triangle. Medium, large and XL have two bottle mounts inside the front triangle
  • Replaceable derailleur hanger or SS insert
  • 12 x 142mm Maxle rear spacing
  • Can fit up to a 2.4” tire (tire size varies by brand, some tires may not fit)
  • Niner head badge

Frame SIR 9
Fork Niner RDO Fork, 15MM
Wheelset NOTUBES 3.30 SS/RAPID, 15MM FRONT, 142 X 12MM Rear
Tires Schwalbe Rapid Rob EVO TL 2.40/Racing Ralph EVO
Brakes SRAM Elixir 5 with 180/160MM G2 Rotors
Brake Levers SRAM Elixir 5
Shifters N/A
Front Derailleur N/A
Rear Derailleur N/A
Crankset Truvativ AKA, 32T
Bottom Bracket SRAM GXP
Cassette Niner Cogalicious 20T
Chain SRAM PC 1
Pedals N/A
Handlebar NINER Flat Top Alloy, 710MM, Red Niner
Stem NINER Alloy Stem, Red Niner Graphic
Grips NINER Grips
Saddle WTB Volt Race with Cr-Mo Rails, Niner Graphic
Seatpost NINER Carbon Seat Post, 400MM, Red Niner Graphic

Note: Components are subject to change without notice.

Size Small Medium Large Extra Large
Effective Top Tube Length 592mm 609mm 628mm 647mm
Seat Tube Length 393mm 419mm 483mm 546mm
Standover Height 716mm 736mm 790mm 842mm
Stack 620mm 637mm 652mm 671mm
Reach 395mm 409mm 423mm 436mm
Head Tube Length 100mm 110mm 125mm 145mm
Head Angle 69.8° 70.3° 70.3° 70.3°
Seat Angle 72.3° 72.3° 72.3° 72.3°
Wheelbase 1085mm 1096mm 1115mm 1135mm
Chainstay Length 440mm 440mm 440mm 440mm
BB Drop 49mm 49mm 49mm 49mm
Front Center 651mm 664mm 684mm 701mm

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Free Shipping Offer

Get free Standard Shipping with your $50 purchase today! Just choose Standard Shipping during checkout.

Please note this offer is only available to physical shipping addresses in the 48 continental United States (no PO Boxes), and oversize charges still apply on some heavy/large items.