The New Niner Sir 9 Hardtail MTB is made from Reynolds 853 Jun 19, 2017

Niner just resurrected the popular SIR 9 hardtail MTB and it was well worth the wait. Use this bike as a 29r or 27.5+ shred sled, or load it up with bikepacking bags, by utilizing its 18 mounting options. These boosted bikes are available as completes or as framesets. Holler at your local Niner dealer for ordering and see more information at Niner! If you’d like to see the fully gallery of images, check them out below.

  • This looks great!

  • Erik_A

    When is All-City coming out with the geared descendant of the Log Lady. I am sure it will be a bit heavier than this Niner SIR 9, but that is what I have my fingers crossed for.

    • Jon B.


      • Erik_A

        Yeah, any All-City insiders know when the geared Log Lady is coming?

  • Davey Struthers


  • Michel Van Aar

    That bottom toptube gusset…..

  • Frank

    This looks great …
    … only I’d prefer a threaded bottom bracket. Am I being too fussy?

    • boomforeal


    • Smithhammer

      I put a Chris King PF on my steel hardtail and it’s been awesome. Not a peep out of it and butter smooth. PF BBs don’t have to suck.

    • Christopher David

      You can still use a threaded BB by using their CYA BB insert.

  • boomforeal

    i appreciate the versatility of this frame: eccentric bb for single speed, light enough for xc riding, progressive geo for trail shredding, tonnes of mounts for bikepacking, etc. a part of me worries that because it tries to do so many things it many not do any of them particularly well, but that’s the part i dislike and am trying to kill


    No threaded BB! I’m out! Sorry Niner, but thats a bad spec right there.

    • Francisco Alvarez

      I always defer to threaded BSA BB but it’s definitely not a deal breaker. I’ve seen plenty of bikes that are running just fine with an eccentric BB

  • Good looking bike – tho very similar to the ROS9 which they’ve seemed to discontinue – wonder why?

  • Eric

    beautiful bike, was super sad when this was delisted from the niner site, wound up pulling the trigger on a older el mariachi instead. so nice to see steel hardtails get love (and attention from mfrs) regardless.

  • Jonathan Gresley

    That bike looks great! But, what’s wrong with the BB, looks like they forgot to put threads in there

    • Armand

      They have an eccentric bottom bracket that gets installed then.

  • Christopher David

    Unfortunately, you can’t run this new Sir 9 as a single speed using Race Face 30mm spindle cranks. The only way to run this bike single speed is to use a crank that has a 24mm spindle.

    • Armand

      Incorrect, Race Face makes a BB that can be used with a 30mm spindle and a standard 74mm shell (found on their EBB setup). Been running this for a couple years.

      • Christopher David

        True. The unfortunate part is that the new Sir does NOT allow for the use of the EBB that allows both 30mm spindle AND running single speed. If you were to set up the new Sir as a geared bike than you could easily run the 30mm spindle. Basically, if you want to run the new Sir as a SS, you will need to use a 24mm spindle with their EBB for 24mm spindles.

  • bicycle640

    I also think this is pretty sweet. I’ve had an old SIR 9 for years, and really like it. Never had issues with the b.b. insert.

  • hiro11

    Why, why, why go with press fit on a steel frame?

    • joshhh

      It also allows eccentric BB use for singlespeed. Not sure if that’s their primary motivation, but it is a definite perk.

  • Mars Marx

    This is NOT a PF bracket, its a EBB, secured with twin hex bolts. On installation put teflon tape on it (as in the instruction) and you never have to pay attention to it again (been using it for three years now)

  • jtbadge

    Anyone picked one of these up yet? There’s not a ton of options for a complete build 29/27.5+ in steel with modern geo between Surly and custom. On paper, it seems like this hits all of the marks.