Sir 9 rear tire widths- Mtbr.com
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  1. #1
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    Sir 9 rear tire widths

    What is a reasonable max width tire on a 30mm internal rim for the rear of the latest 2018-2019 Sir 9? I know the website says 2.4 but with that newer wider yoke and the ability to put 27.5 x 2.8 in the rear, one thinks that it could be greater than 2.4.

  2. #2
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    This is a slight pain point for me. It comfortably fits a 27.5 x 2.8" tire on a 40mm internal rim width, but a 2.35" Nobby Nic on an Industry Nine Trail 29" 245 (24.5 internal rim width) BARELY FITS. Not a hugely aggressive tread and not on a wide rim, would say 2.4 could be pushing it. Seriously. Tried fitting my Hightower's Aggressor 2.5" fitted onto a Reserve 30 29" and no dice.

    Let me know if you have any questions, I'd personally recommend 27.5+ for it though.

  3. #3
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    I'm late here but I could use some help too. I also have 30mm internal width rim. I tried a Maxxis High Roller II 2.3 and it would pick up rocks and shove them right into the chainstay yoke, which is now extremely scratched up. I'm going to try a Maxxis Ikon 2.35 that should pick up less rocks and has a bit of a rounder profile. Niner currently specs a Maxxix Rekon 3C/EXO/TR 2.4 WT on a 26mm internal width rim, which seems like it would also be an incredibly tight fit. I'm open to suggestions! Thanks.
    Last edited by Rodmunch; 02-10-2020 at 11:16 AM.

  4. #4
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    Quote Originally Posted by Rodmunch View Post
    I'm going to try a Maxxis Ikon 2.35 that should pick up less rocks and has a bit of a rounder profile.
    Didn't work out. The clearance is still really bad. It rubbed the frame a few times. Back to the drawing board!

  5. #5
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    I also found that Niner has a spec with 30mm internal width rims and a Rekon 2.4 WT. How do they make that work?

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    I recently purchased a SIR 9 from Jenson USA. It has 29" 30mm wheels and came with 2.35 Knobby Nic's. I didn't check clearance with the Knobby Nics before replacing them with 2.35 Vittoria Mezcal. With this tire, there is not much clearance at all. It was tight enough that I replaced the rear with a 2.25" Mezcal. Clearance is still tight. I've measured the 2.35 as a true 2.35 and the 2.25 comes in at 2.3.

    I don't know how a 2.4 could be used in the rear.

  7. #7
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    Thanks! Yeah I have the Jenson SIR9 also. I'm going to try a 2.25 Maxxis Rekon and report back. For the time being I've been running a tubeless 2.35 Nobby Nic.

  8. #8
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    Quote Originally Posted by Rodmunch View Post
    Thanks! Yeah I have the Jenson SIR9 also. I'm going to try a 2.25 Maxxis Rekon and report back. For the time being I've been running a tubeless 2.35 Nobby Nic.
    The Rekon fits! But the sidewalls stick out just a bit wider than the tread making them more vulnerable. I'm happy so far until I can get a narrower rim.

  9. #9
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    Quote Originally Posted by Rodmunch View Post
    The Rekon fits! But the sidewalls stick out just a bit wider than the tread making them more vulnerable. I'm happy so far until I can get a narrower rim.
    I was thinking about one of these, so I'll be curious to hear your findings. I was hoping for at least a 2.35 in the back with no issue on stock wheels... And I like Recons.

  10. #10
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    I think a 2.35 Rekon would be pushing it. You'll have minimal clearance.

    Just checked...there's only a 2.35 available in the Rekon Race, not the regular Rekon.
    Last edited by Rodmunch; 05-24-2020 at 05:32 PM.

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