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The award for best ride quality has always gone to steel. That’s where the Niner S.I.R. 9 frame shines. The S.I.R. 9 isn’t just steel, it’s Reynolds 853—one of the best, most respected steel alloys for bicycle frame-building. Because of this, the S.I.R. 9 has that legendary ride quality that everyone else is chasing. Sure, it may be a little heavier than your dentist’s carbon fiber frame, which costs more than your car, but it rides better. And, while we agree that the S.I.R. 9 is a little bit old-school, it isn’t behind the times. You get 142mm rear spacing, a post-mount rear caliper, and the option to run just about any drivetrain configuration out there, from singlespeed to 33-speed.
The secret behind all this drivetrain diversity is the eccentric bottom bracket. The EBB makes setup simple, unlike individual adjustable dropouts.
If you plan on going the geared route, Niner recommends doubles not exceeding 26/39 chainrings for SRAM, and 28/40 for Shimano. However, a standard triple will pose no problems. The rear triangle will accommodate a 2.4in tire, and you can run a 160mm rear rotor. You’ll need a bottom pull, high mount front derailleur with a 28.6mm clamp. The S.I.R. 9 uses a 27.2mm seatpost, a 73mm BB (only external style bottom brackets work with the EBB), and a 44mm tapered headset. The maximum chainring size varies depending on the position of the BioCentric EBB insert. At the most rearward position, the Niner recommends running no larger than a 30t chainring, and when in the forward position, it will accept a 36t ring. It comes with a Maxle rear axle.
- Reynolds 853 steel frameset
- 142mm rear spacing
- Eccentric bottom bracket
- Item #NNR0030
- Q & A
Very happy with this frame
- Familiarity: I've used it several times
I built the frame up XT 1x11 and easton wheels, coming in at around 21 pounds total for a large. I am really pleased with the way this rides, and it's trustworthy steel! The attention to detail is obvious in the welds and workmanship. If you want a lightweight but modern steel frame this is one of the few that checks all of the boxes. I am also really happy that Competitive Cyclist pays attention to detail before shipping their frames. They do prep work like reaming and facing the head tube, etc. Saves time and money on your build.
Modern-technology be damned, sometimes
- Familiarity: I've used it several times
I've loved the idea of a steel bike since the beginning. There are (literally) millions of threads and blog postings talking about why steel is still a relevant (and good) material to use for bike frames, so I won't delve into all of that. I came off a Pivot LES, and a Highball Carbon before that, so I've had my fair share of creme de la creme carbon hardtails. To feed my never-ending lust for steel, I decided to give the new SIR9 a try. The stereotypes are true - it's pretty heavy, it is really smooth (smoother in the rear than either of my previous carbon hardtails), and is relatively heavy (yep, it's like a pound or two heavier than my other frames were). But for me, especially this time of year, I don't really care all that much. I don't have to worry about damaging the frame (I suppose I need to be conscious of rusting, but FrameSaver should take care of that), and it's pretty inexpensive. And it's fun, and different. And it's easy to make it single speed or geared. I dig it - when spring rolls around and I go back to slogging up thousands of feet of vertical, my tune my change a bit, but as a cool all-around hardtail (especially for midwest riding), this thing is rad.
Does this frame come with the derailleur hanger?
WIll my S Roval 142 wheel set fit? It uses a Syntace axle not a Shimano. Thanks.
If the rear end is a 12x142 it will fit. You will just need to use the axle that comes with the Niner frame as the treads in the frame are different.