New Niner SIR9 with Custom Reynolds Tubing Proves Yes SIR-ee, Steel is Real…Modern

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube

The all new Niner SIR9 was developed with heavy collaboration from Reynolds to develop some unique tube shapes with their high end 853 chromoly.

The new SIR9 frame uses a custom bent 853 DZB (Double Zone Butting) downtube, something not typically done with that type of steel tubing, and mates it with a 631 44mm headtube. The latter lets you run either a modern tapered fork with the included external cup tapered headset, or use an internal headset with a straight 1-1/8″ steerer fork.

It’ll come stock with their Biocentric II bottom bracket system and is compatible with their CYA BB inserts, so you can run it singlespeed or with any geared-type bottom bracket design (PF30, BB30, PF92 and threaded external cup). The other major update is a Maxle 12×142 rear axle.

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube

The bent downtube isn’t new in and of itself. The magic was in Reynolds’ ability to use their top end 853 steel and do it while maintaining strength. The dual butting profiles put thicker tube walls at the headtube, then thinner butting profiles elsewhere. The benefit is the lively ride and lighter weight with improved fork crown clearance. Typical straight tubes meet really high on the headtube, in many cases joining the top tube in a conjoined section. This minimizes contact with the headtube and doesn’t allow for the strongest junction. The new SIR9 gives the frame adequate separation between tubes for a stiffer, stronger front end.

The 44mm headtube first found love among handmade builders looking to offer modern tapered forks. For Niner’s steel bike fans, this lets them run their tapered-only RDO carbon fork on the new SIR9, along with any other tapered 1-1/8″ to 1.5″ forks.

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube

The stays are custom 3D bent and shaped steel with investment cast dropouts and seat- and chainstay bridges. The shaping provides heel and tire clearance and maintains a lively ride while the 12×142 axle and strong dropouts keep it properly stiff.

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube

The geared bikes get dropouts with a derailleur hanger…

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube

And the singlespeed dropouts are extremely clean and minimal. Post mount brake tabs are located inside the rear triangle with a nice, bullet-shaped upper mount tucked into a bend in the seat stay.

There’s no adapter or spacer to let you run your standard 135mm QR wheels, so you’ll need to upgrade your rear hubs (or, hopefully, just put on new end caps) to 12×142.

2012 Niner SIR9 steel singlespeed hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube

2012 Niner SIR9 steel hardtail singlespeed and geared 29er mountain bike geometry chart

2012 Niner SIR9 steel hardtail 29er mountain bike specs

For a size Medium, claimed painted frame weight is 2,100g (4.36lbs) without any hardware. With rear Maxle, seat collar, EBB and headset is 2,390g (5.27lbs).

LIMITED EDITION IMBA FRAMES

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube and limited edition IMBA charity auction frames

Want one of the new SIR9 frames? You can wait about six 12 weeks until they start shipping, or you can bid on one of six limited edition IMBA frames and get yours much, much sooner. These custom frames are being auctioned off starting Tuesday evening, June 19, to raise money for IMBA and will ship shortly thereafter. Become a fan of Niner on Facebook to get a link as soon as the auction goes live.

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube and limited edition IMBA charity auction frames

The auction includes 1 small, 2 medium, 2 large and 1 XL and include matching RDO forks, as shown here.

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube and limited edition IMBA charity auction frames

2012 Niner SIR9 steel hardtail 29er mountain bike with custom Reynolds tubing Maxle 142x12 rear end and 44mm tapered headtube and limited edition IMBA charity auction frames

Comments

David Willcox - 06/19/12 - 10:45am

Almost Perfect……. just needed ability top split stays somehow.

DaleC - 06/19/12 - 11:06am

I love my SIR9 and this looks like a pretty decent improvement… not enough to trade, but nice to see the model has new life.

Primo - 06/19/12 - 11:29am

why can’t eccentric bottom brackets go away already

Matthew - 06/19/12 - 11:43am

Oh boy! I can already hear these frames snapping in the distance!

Denis - 06/19/12 - 12:37pm

Who cares? We wanna know if there will be new colorways for the air9 rdo frame? ;-)

Steve M - 06/19/12 - 1:48pm

Are they going to form a new company called 650b’er?

DaleC - 06/19/12 - 2:54pm

Matthew – does Reynolds have a failure problem that I, nor anyone I know, have never heard of…. and can’t find on the web?

pfs - 06/19/12 - 3:54pm

Matthew – i know niner sells in europe so ide be willing to bet these frames pass EN. thats not something most steel frame manufactures can say, at least not in the same sentence as light weight.

DJ - 06/19/12 - 8:40pm

Primo – not sure what your problem is. I wrapped the CYA with teflon tape, no creak’s, you can have a lower or higher cranks. Sweet!

Alex - 06/19/12 - 11:15pm

Newsflash – steel is STILL the best overall compromise among cost, performance, and durability. 150 years on, who’da thunk it?

fuzzbuzz - 06/20/12 - 4:15pm

Steve M – They are starting a new company called “Beiber”…should be a hit with teenage girls or men that act like teenage girls….

Joe - 06/21/12 - 12:19am

So let me see if I understand this correctly –

You take a few normal technologies that are already present on other steel production frames, make a claim that you are the first, put an outdated eccentric BB on it, and charge more for it? Derp?

Tywin - 06/24/12 - 6:48am

Look pretty nice, all my bikes are steel so I’m sold on that idea…

The rear disc caliper mounts are art in themselves too, nice touch.

DaleC - 06/24/12 - 12:01pm

Joe – and where does this article claim to be “first” on anything? This particular combination of tubes and materials, is, in fact, new. In fact, the article says “The bent downtube isn’t new in and of itself.” Derp? Yes, for your comment.

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