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  1. #1
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    Rim width and Tire size

    What is the minimum recommended rim width for me? I am running Easton XC Two 29er wheelset with Maxxis Ardent 2.4 up front and Panaracer Rampage in the rear.
    I am a clyde at 230lbs with gear and am 6'3" tall. I have an aggressive riding style.
    I usually run 28 PSI in the front and 33 PSI in the rear.

    I have heard many good things about wider rims, but how narrow can I go without "squirrely" handling or high risk of the tire coming off the rim?

    Here is Easton's profile of the rim, I added in the red and blue measurements (close approximation).

    I welcome any information or opinion, thanks!
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  2. #2
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    For a 2.4 tire, I'd choose a 28mm rim or larger. I run the Ardent 2.4 on 28mm and 35mm wide rims. I run mine at 22 psi or 25 psi depending on the rim size. I'm 170 + gear.
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  3. #3
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    Do you mean 28mm outer diameter on one set of wheels and 35mm outer diameter on another set of wheels? If so, what are the inner diameters?

  4. #4
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    I run 2.4 Ardents on Stans Flow rims & run as low as 18 psi on the front.

    I'm 6 ft & 173 lb

    I also have a set of stans Arch rims & I like the wider flow's more.
    I have a 6 Berth Motorhome that I rent out . It is based in Tauranga, New Zealand

  5. #5
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    A rim with a 23mm internal width would be ideal. You could go wider with no problems.
    Tire Design & Development Engineer. The opinions expressed in this forum are solely my own.

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    I'm gonna miss me when I'm gone.
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  7. #7
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    Quote Originally Posted by kona29er
    Do you mean 28mm outer diameter on one set of wheels and 35mm outer diameter on another set of wheels? If so, what are the inner diameters?
    Sorry, yes, those are two different wheelsets. The 35mm is the P-35 from Velocity, likely a 30mm inside width. The 28mm is the DT Swiss 5.1D/EX500 which has an inner width of around 23mm. The P-35 rim is really nice - I'm thinking about replacing the DTs with them if I ever fold the wheels.
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  8. #8
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    I'm on a MC29 with DH19 rims and was wondering the same thing, but about a month ago put the Ardent 2.4 up front and have been riding the $h!t out it. I'm running tubed and found the sweet spot to be 22-25psi and had no problems at all even through stuff I would have pinch flatted for sure on my 26in tires. I'm 175, so it sound like 28psi should be fine you.

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  9. #9
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    Thanks for the info, guys. Does anybody feel that I pushing my luck in terms of safety with the PSI I am at? I am half looking for a reason to ditch my XC Two wheels in favor for something that doesn't need truing.
    Let me know if anybody wants an XC Two wheelset for uber cheap, lol.

    John, your words offer some relief, except that I have been gathering that wider really is better, and I would like to drop my PSI a bit. It would be nice to throw on a WTB Dissent without feeling like a tool (DH tire on XC rim.)

  10. #10
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    Put some flows on it & be done with it.
    You will love it.
    Do the easyest test there is,grab a broom handle & mark it in inchs from the centre with 17 in (your rim is 17mm ) then 24 in then 65 inchs.Get your wife or someone small to hold it out on the tire marks & you hold it in on the narrow rim marks & see how little control you have when they push on each end of the handle,now put you hands out to the 24 inch mark & see how much more control you have.

    Wider rims will help your speed heaps.
    I have a 6 Berth Motorhome that I rent out . It is based in Tauranga, New Zealand

  11. #11
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    Ardent 2.4's are squirmy for me and can't run them soft enough on 21mm internal rims, I'd really like 25mm internal rims.

    I run with my 26" setup, 29mm internal with RQ2.4 on the front and thats amazing.

    Careful though, wider rim makes for a squarer profile which on the rear especially really slows the bike down, so stick to 21mm max in the rear, but front 29 is fine.

    There is generally 7mm's difference between internal and external, give or take 1mm.

  12. #12
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    Thanks for the insight, I have a an Ardent 2.4 on my WTB Laserdisc Trail 29 rims up front on my Monocog Flight. I think it is 21mm inside, which certainly feels better than my Easton XC Two at 17mm. I'm trying to save money for Mikesee's wheels with the Sun Ringle MTX-33. Then I can just forget...
    I usually run a smaller tire in the rear anyways (currently a Rampage 2.35, so its still pretty big.) Although I can't really say I've noticed much squirm, I can certainly feel that both tires on both the Flight and my Hei Hei 2-9 with the Easton wheels don't want to bite when cornering. I've slid out more than a couple of times on dusty stuff.

  13. #13
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    would a xking 2.4 still stay on a 20mm inner diamiter rim thogh?

  14. #14
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    Would it be better to run a narrower rim in the rear than front if sold on 2.0 rear and 2.4 front?

  15. #15
    Carbon & Ti rule
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    I have always liked running the same.

    Quote Originally Posted by party_wagon View Post
    Would it be better to run a narrower rim in the rear than front if sold on 2.0 rear and 2.4 front?
    I have a 6 Berth Motorhome that I rent out . It is based in Tauranga, New Zealand

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    zombie thread, but the best search result. I'm confronting the same issue; I want to be able to run 3" tires on my 29er wheelset, but also want compatibility with 2.5, 2.6" range tires in case 3" fades.

    a few data points:

  17. #17
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    I find your info dated. And it's not that simple.
    Different tires the same width can require different width rims for max performance from each tire.
    A high volume very rounded tire can make use of a wide rim say 35mm for a 2.3-4" tire with a 120 tpi flexible sidewall. 50mm for a 2.8-3.0 tire with similar characteristics.
    At the other end a thick sidewalled heavy tread low volume tire meant for dh speeds or cut prone tech terrain can need a 25-30mm rim so it doesn't get too squared off.
    So look at the weight and construction of the tire you need for your terrain to choose the rim.
    Be aware that wider tire rim combos run at low pressures may not need big knobs because of the larger footprint they create.
    So if you need a big knob tire for enough traction on a skinny rim the same tread pattern my not be needed when you look at wider tires and rims. Faster rolling lower tread height small knob tires may work better overall when you've got more tread on the trail in curves.
    And you have to play around with pressure because 1-2 psi can make a noticeable change.

  18. #18
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    Quote Originally Posted by eb1888 View Post
    I find your info dated.
    as do i; thats why i included Dates I don't know how things have changed, though; hence the question

    I think what you're saying is that current thinking actually use _narrower_ rims than when mid-fat first came into vogue?

    inner-width == ~~50% tire width for flexible tires in less-sharp terrain; reduce from their for heavier tires and nastier riding?

  19. #19
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    I'm not saying that.
    I'm not saying a 2.8 71mm tire should get a 35mm inner rim. I'm saying 45-50.
    Rounded/flexy 2.35-2.4 can use a 35 or maybe a little wider rim.
    Some tires will perform better on wider rims. Some won't.
    Some 2.3-2.4 tires that were designed originally for 19mm inner width rims get too squared off with a 30mm rim. Or you have to use too high psi to keep them from being too squared. The same size tire designed more recently with more volume and a more rounded profile will outperform those tires by making use of a wider rim and lower psi to create a bigger footprint in cornering. This mostly applies to 2.3-2.4" tires or some WT Maxxis where they just moved the knobs.
    2.5 and 2.6 tires that are coming should be looked at based on tire volume, tread width/knob size, rounded profile and sidewall thickness/flexibility.
    There are more and more tuning options. One tire and rim size won't be your best choice for everything.