Niner Bikes S.I.R. 9 29er Hardtail

4.8/5 (65 Reviews)
MSRP : $999.00

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Product Description

The S.I.R. 9 is the most versatile bike in the Niner stable, fusing the ?steel is real? feel of a new Reynolds 853 DZB tubeset with the ability to run the frame as either a geared bike or single speed with Niner?s ultra-light eccentric bottom bracket. New BIO-CENTRIC II BOTTOM BRACKET SYSTEM! The Niner Bio-Centric II makes adjustments easy across a wide range of gears and eliminates the need for adjustable dropouts, giving the cleanest possible solution for singlespeed use. No bolt on hubs, no chain tensioners cluttering your ride, no brake adjustments with gear changes. While tubing upgrades are the focus of this new design, Niner has not forgotten the details. The new the S.I.R. 9 uses 142x12mm spacing with an included Maxle for added rear-end torsional stiffness, removable downtube cable guides, post mount brake bosses between the chain and seatstay for braking precision and, of course, the Niner headbadge and two great color options for that finishing touch. The S.I.R. 9 is truly a do-everything frame. Run it single speed at your local race, then convert it to a full gear set to do the Trans-Alp. Want a 1 x 10? No problem. Or, if you?re just not sure, the S.I.R. 9 will give you the option of trying it all. Features: -Sizes: S, M, L, XL -Available Colors: Hot Tamale and Arctic White -Custom-bent double-butted Reynolds 853 DZB downtube. -44mm Reynolds 631 head tube allows use of tapered or 1?1/8? forks. -Compatible with a rigid or 80 - 100mm travel suspension forks. -Niner Bio-Centric II Bottom bracket system and removable downtube cable stops for clean singlespeed or geared setup. -44mm head tube compatible with tapered steerer forks. -Rear Hub Spacing: 142mm x 12mm (Maxle axle included with frame) -Up to 2.4" rear tire clearance. Please note that if you are interested in a single speed specific build, please contact the Wrench Science Niner specialist.

User Reviews

Overall Rating:5
Value Rating:4
Submitted by S.O.B. a Cross Country Rider

Date Reviewed: December 17, 2012

Strengths:    This is not your papa's steel. This frame is relatively light for a steel frame @ ~4.5lbs (2042g). Love the clean lines of a steel framed bike.

Weaknesses:    Some might say the ebb, but I prefer this to sliders. This particular frame is set up with gears, so the ebb is a non-issue. No weakness that I can come up with and I have had this bike for almost a year now.

Bottom Line:   
I always use to joke, Steel is real...real heavy! Not so much the case with the SIR 9.
Purchased this bike as a backup/wife's bike...built up geared (1x9) to be used by me on occasion in place of my lighter (stiffer) Scandium One 9. I was impressed that the frame was only ~1.2 lb (or ~540grams) more...what was amazing is how it felt on the trail. I took it to a familiar trail, very rooty, rocky, was noticably smoother, and with the components almost identical to the One 9, it was only ~2lbs heavier. Did I notice the weight? Sure I did, when picking it up to place on the car rack, I did not feel it on the trail...I thought maybe I did on the climbs, but that could be the placebo affect of knowing you are riding a bike 2lbs heavier than your normal ride. Love the bike and will certainly use it in the future where a geared bike makes more sense (like trails with steep, grainy climbs)...other than that, it will serve as my wife's main ride (glad we ride the same size bike). :)

Expand full review >>

Favorite Trail:   286 (NC) Auburn SRA

Duration Product Used:   9 months

Price Paid:    $700.00

Purchased At:   Back Alley Bikes

Similar Products Used:   Misfit Dissent, Niner One 9

Bike Setup:   Stans, Thomson, Schwalbe, Avid, XT, Reba...

S.I.R. 9 / Niner Headset Assembaly Question...

I have a Niner headset (shown in picture) and feel that I installed it correctly however there's the slightest gap thats created by the compression ring... is that supposed to be there? I'm holding off cutting the forks until i get this figured out... thanks for anyone that can provide some insight! ... Read More »

Niner S.I.R 9 vs One 9 RDO?

The previously mentioned bikes are on my shortlist for my new single speed. Has anyone had experience with either of these bikes? Good or Bad? Any idea on stock weights? Sorry if this subject has been beaten to death but the Almighty Google is giving me nothing. [url=] ... Read More »

New S.I.R. 9 - IMBA Limited Edition Auction starts tonight!

Want the new S.I.R. 9 with 44mm head tube and 142x12 spacing? Want one of 6 that we have had painted for our IMBA benefit? The auction starts tonight - as soon as it is live we will post the link here and on our Facebook page. 100% of auction proceeds from this brand new product launch go to IMB ... Read More »

Niner S.I.R. 9 - First SS, First Build

So my first real post on mtbr, taken me a while, need to stop being such a lurker. (My first 5 were so I could post this in the SS forum, rather than general). I want to build a SS 29er, I've got some idea of the kind of bike I want, and I have the money (or will as I buy components) to put it t ... Read More »

Niner S.I.R. 9 Opinions

Hey guys what do you think of the Bio-Centric BB system? I am pretty much at wit's end for the ideal steel bike for SS and geared platform. I go either a Niner or something else. A bike I can race with but have fun with a SS, it must be steel or ti. A bike frame to end it all.Read More »

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