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Niner SIR 9 5-Star X01 Eagle Bike: Made from metal. SIR 9 is made from rugged, reliable, comfortable Reynolds 853 steel.

There’s a new bike in town. It’s built to last and not let you down. When you’re spinning up the steeps, 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.

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  Yes, SIR

  So what’s the story with our steel hardtail? For starters, it’s STEEL. This classic metal alloy from materials icon Reynolds gives us the comfortable, durable, capable, versatile, “ride it hard and put it away wet” frame that we have always wanted.
  
  To make it even more tasty, the SIR 9 is strapped with a 120mm travel FOX suspension fork, perforated with no fewer than 18 threaded, reinforced mounting points, clears 29x2.4” (or 27.5x3.0”) tires, and offers easy options for geared or singlespeed drivetrains. We’ve even got custom frame bags made by Defiant Packs in Carbondale, Colorado. No excuses - pack an extra jacket and a PBR, go farther, and stay out longer.
  
  The SIR 9 is perfect for just about any type of riding, no matter how long or short. It’s a butt-kicking, grin-inducing lunch ride launch pad when you only have 30 minutes to burn in the back lot. It’s also made for multi-day missions in the backcountry. And it’s made to make you happy the minute you throw a leg over it.

  

  Get real with Reynolds 853 steel

  This modern metal alloy is well known for its unique properties. It actually strengthens in the tube junctions when it air-cools after welding. So, we can do more with it, yet we actually can use less material. For instance, we can design intricate chainstay and seat-stay yokes to accommodate either 29” or 27.5-Plus wheels and tires, with plenty of mud clearance to spare. We also don’t need to add heavy gussets and tube reinforcements - it’s plenty strong as-is.

  

  “Trail country” geometry

  Blurring the lines between modern trail bike geometry and traditional cross-country geometry, the SIR 9 occupies a niche we lovingly call “trail country.” If you’re doing a combination of long pedaling rides, stiff climbs, extended descents, and spicy technical sections, you’ll love what we’ve done here. “Trail country” geometry translates to modern trail manners when you need them most, with no sacrifice of efficiency or agility.
  
  The roomy cockpit has a comfortable reach for short stem lengths, giving you quick handling and plenty of maneuverability to blast through rock gardens and cut hard corners. The steep 74-degree seat angle gets you centered over the BB for climbing and pairs nicely with the short 430mm chainstay length for supreme pedaling efficiency.. And of course, the slack, 68-degree head tube angle and long wheelbase contribute stability and self-confidence when you’re dropping into the steepest lines.
  
  

  Pack it up, pack it in, let me begin...

  The versatility of steel gives us the option to add accessory mounting points, and boy did we ever. There are rack and fender mounts, bottle cage mounts, frame bag mounts, and even a top-tube bento box mount. The rear rack mounts are strong enough to hold 55lbs.
  

  

REYNOLDS 853 STEEL PROVIDES THE SUPPLE, COMFORTABLE RIDE THIS LEGENDARY MATERIAL IS KNOWN FOR.
COMPATIBLE WITH 29X2.5 OR 27.5X3.0 TO OFFER THE CHOICE OF MAXIMUM ROLL OVER OR ULTRA TRACTION AND STABILITY.
REVISED GEOMETRY IS OPTIMIZED FOR MODERN TRAIL RIDING, LONG DAYS IN THE SADDLE AND ALL AROUND GOOD TIMES.
INTEGRATED BAG MOUNTS INSIDE FRONT TRIANGLE.
BENTO BOX MOUNTS ON TOP TUBE OFFER ADDITIONAL STORAGE OPTIONS WITHIN REACH.
73MM PF 30 BB SHELL IS GEARED OR SINGLESPEED COMPATIBLE WITH THE NINER BIOCENTRIC 30
148 X 12 BOOST REAR SPACING
COMPATIBLE WITH 1X (MAX RING 36T) AND 2X (26/36 OR BIGGER) DRIVETRAIN SYSTEMS
COMPATIBLE WITH 2X (26/36 OR BIGGER) DRIVETRAIN SYSTEMS, 34.9 SIDESWING FRONT PULL FRONT DERAILLEUR
73MM PF30 BB SHELL (ADAPTERS REQUIRED FOR BSA TYPE BBs)
COMPATIBLE WITH BIOCENTRIC 30 FOR SINGLESPEED USE
30.9 SEAT POST
31.8 SEAT COLLAR
1.125" X 1.5" TAPERED ZERO STACK HEAD TUBE, 44MM UPPER, 56MM LOWER, CANE CREEK DESCRIPTION: ZS44/28.6 ZS56/40
34.9 SIDE SWING, FRONT PULL FRONT DERAILLEUR
POST MOUNT DISC BRAKE - 180MM MAX ROTOR SIZE
148 X 12 REAR SPACING
ALL SIZES HAVE 2 INNER TRIANGLE BOTTLE MOUNTS, 1 MOUNT UNDER DOWN TUBE
CAN FIT UP TO A 29 X 2.5 OR 27.5 X 3.0 TIRE (TIRE SIZES VARY BY BRAND, SOME TIRES MAY NOT FIT)
COMPATIBLE WITH STANDARD 1X (36T MAX), 2X AND 3X SYSTEMS