Niner’s SIR 9 is back!

The classic steel hardtail is back and more versatile than before

Niner’s classic steel hardtail is back and more versatile than before.

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Niner SIR 9 highlights

  • Compatible with 29in and 27.5+ wheels and tires
  • Slacker geometry than the previous version
  • Reynolds 853 steel front triangle
  • Boost axle spacing
  • 18 mounting options for bottles, bags and other accessories
  • Redesigned chainstay yoke claimed to improve stiffness
  • Complete bikes pricing from $3,000 to $6,000 (UK and Aussie pricing TBC)
  • Frame-only pricing at $1,200 (UK and Aussie pricing TBC)
  • Available now
The SIR 9 can roll on 27.5+ (shown) or 29er wheels and tires
Niner Bikes / Ian Hylands

This ferrous-framed 29er still relies on high-quality Reynolds 853 steel for the main frame but with more trail-oriented geometry than its predecessors. It appears that Niner blended elements ROS 9 into the latest SIR 9.

“The new frame is really a fusion of the SIR with the high quality 853 steel, the ROS geometry, and the ROS 9 Plus versatility,” said Brad Cole, Niner’s marketing manager.

Unlike its cross-country focused predecessor, the new SIR 9 is designed around a 120mm travel fork. The 68-degree head tube angle is approximately three degrees slacker.

Reach numbers grow longer across the four-bike size range, while chainstay length shrinks by 13mm to 427mm/16.8in.

The SIR 9 is slacker than the previous version
Niner Bikes / Ian Hylands

Versatile frame design

Integrated mounts for frame bags make the ROS 9 look very clean in bikepacking mode
Niner Bikes / Ian Hylands

The new SIR 9 checks off a lot of boxes for a modern steel hardtail. It’s compatible with a 30.9mm dropper seatpost and can be built up for a multitude of uses.

The frame uses a 73mm PF30 bottom bracket shell. Riders can convert the frame for singlespeed use by installing Niner’s Biocentric 30 bottom bracket system.

The SIR 9 uses a PF 30 bottom bracket shell
Niner Bikes / Ian Hylands

Many full suspension designs are now 1x-specific, but this hardtail still offers the option to run a 2x drivetrain with a side-swing front derailleur. 

Despite the big-wheel brand name, Niner has also embraced 27.5+ wheels and tires. The SIR 9 has clearance for 29×2.4 or 27.5x3in tires.

In addition to wheelsize versatility, the frame offers a pair braze-ons on the top tube for an integrated bento box.There are additional mounts in the mainframe so bikepackers can run a strapless frame bag. Lastly, a trio of mounts on the bottom of the down tube allow for an additional water bottle or cargo-carrying possibilities.

SIR 9 Pricing and availability

The SIR 9 is available as a complete bike or as a frame
Niner Bikes / Ian Hylands

Niner offers the SIR 9 in nine different built kits with your choice of 27.5+ or 29er wheels. The options start with the $3,000 SLX kit and top out with the $6,000 XO Eagle build. (UK and Australian pricing have yet to be announced.)

The SIR 9 is available now. The frame-only version of the SIR 9 retails for $1,200. 

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