Preview: Niner Bikes S.I.R. 9

Sure, steel is real, but who said it has to be retro? Niner proves with its S.I.R. 9 that it doesn't have to be.

Niner Bikes S.I.R 9
$999 (frame-only) / ninerbikes.com

By Kevin Rouse

Niner Bikes is looking to prove that steel has a solid spot on the list of modern mountain-bike building materials.

Their argument for ferrous fabrication?

Look no further than the completely redesigned Niner Bikes S.I.R 9. Centered around a proprietary steel tubeset that includes a custom-bent Reynolds 853 downtube, the S.I.R. 9 promises to be as unique as one of Sir Elton John’s custom-tailored suits, but, since it is indeed steel, as classy as Sir Ian Fleming, and, equipped with host of modern accoutrements, as innovative as Sir James Dyson (think vacuums, people).

Sure, steel carries a definitively retro vibe to it, and it isn’t without reason. Thanks to the Bessemer process steel first became commercially feasible on a large scale back in 1856, not too long before the first chain-driven bicycle was introduced. Now, with the SI.R. 9, Niner is looking to give steel a bit of a technological makeover. With welcome additions to their venerable steel hardtail, such as tapered fork and through-axle compatibility, the Niner S.I.R. 9 can now boast the latest and greatest in mountain-bike frame technology.


The Niner SI.R. 9 promises to be a popular offering.

The Niner S.I.R. 9 ships with dropouts for both singlespeed and geared use, and every frame comes standard with Niner’s Bio-Centric II bottom bracket which offers plenty of adjustability for singlespeed applications, making gear changes a much less labor-intensive affair.


Keeping the material current, Niner Bikes equips its S.I.R. 9 steel hardtail with a 44-millimeter headtube that will work with either a 1-1/8″ steerer (with an internal headset), or with a tapered steerer and the Niner-supplied external cup headset.


The Niner S.I.R. 9 rear triangle utilizes proprietary, custom-bent steel that is shaped in 3-dimensions to allow for finely tuned ride characteristics.


The SIR 9 also features post-mount brake mounts in addition to 142×12 through-axle compatibility. The Niner SIR 9 ships with a Maxle through-axle already included.


Investment-cast seat and chain stay bridges allow for increased clearance—up to 2.4-inch treads.

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Add a Comment

  • Boneal

    Would really like to see this with sliders, alternator dropouts or track ends.

    - Single speeder

  • http://www.muskokaoutfitters.com Peter

    Sweet upgrade on the frame but is that a Niner RDO Carbon Stem?

  • jcitizen

    A beautiful ride without a doubt, but wonder what their take is on belt drives at Niner?

  • Mike

    Won’t happen with the SIR since it is designed to be versatile as a geared or SS frame. I think the MCR will get discontinued soon since the new SIR9 also accepts Niners CYA BB inserts to run whatever flavor BB type you want, so no reason to offer a geared only steel frameset.

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