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  1. #1
    zul
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    Bottoming Out Mojo HD 160: Tire hitting seat tube.

    Anyone else having this prob?? Ever since I got this bike it's been a problem where the rear tire rubs on impact into the seat tube where the der cable. I ride rough trails, rock gardens, drops, g-outs and small hucks. I've tried everything and still bottoming out. Tired of replacing der cables. This must be a setup issue. Here's what I've done over the past 18months:

    1. Lower volume tire (Minion instead of Ardent)
    2. Increased air pressure in the Fox RP23
    3. Purchased Cane Creek Double Barrel Air
    4. Increased air pressure in the CCDB

    If you are on CCDB Air, How much do you weigh ?? and what shock air pressure do you run????? I am 165lbs running 130lbs in the shock ... Still bottoming out ... WHAT!!?? Yes.

    5. Added one of the small volume spacer reducers. Still at 165lbs and 130 lbs air pressure ... AND Finally .... NOT bottoming out. This is not recomended online or by any of my mechanics ... ?!? But it's keeping this tire off of the seat tube. Hmmm.!?

    Feeling like this setup maybe way off ... WAY off. I know the dials have a lot to do with the situation. Any thoughts, help or suggestions PLEASE !!!

    Thx - zul
    If lovin you is wrong, I don't wanna be right

  2. #2
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    I run a ccdb air and I'm around your weight 72 Kgs I might be a bit lighter but I carry a lot of **** in my camelbak so we are probably even and ride similar terrain. I run between 100-110lbs and no spacers and don't have a problem with bottoming out. I think I probably have the old ccdb air without the hiflo inner but it shouldn't make too much difference. I only run 1x10 so I don't have to worry about the derrailleur cable.

    The only thing I can think of is that something might be little loose in the shock mount or linkages, lopes and/or lower that is allowing a bit more travel.

    Do you have the old rear end with the 135x12 axel? these HDs have less clearance in the front triangle. The latter models with 142x12 have an indentation in the seat tube for a little more travel. Also I think they route the front der. cable to the side so the tire can't hit it.
    Last edited by d3toid; 01-25-2014 at 02:34 AM.

  3. #3
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    Lose the fox. Or at very least add volume reducer kit from fox - will help

    I am loving the X Fusion vector air (DW tune)

  4. #4
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    Putting a spacer in the DB is fine. As far as pressure it does sound high for your weight, how much sag are you getting? Generally you should set air pressure for proper sag and then adjust your high speed compression to limit bottom out.

  5. #5
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    are you running 27.5 on an HD? If yes, then you need to shim. If 26...you should not be hitting the seat tube.

  6. #6
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    Post some pics. Something's not right. I've launched my hd off some big drops and have never rubbed the seat post.......accept the time I blew a monarch plus at n* 👍

  7. #7
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    Post some pictures if you can, let all the air out of the shock and fully compress it to see exactly where it is hitting. Is it hitting the front der cable or the actual seat tube?

  8. #8
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    Tons of tuning capability on CCDBA. Try a touch more low speed - assuming you are bottoming on compressions. I would go one click HSC and two clicks LSC.
    Don't make the mistake of thinking that landings to transitions are a HSC moments as they are normally low speed due to shaft travel over time.

  9. #9
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    It happens on the 135 frames with bigger tires mounted. Happened to my buddy today with a Hans Dampf on the rear. Rear shock is not going to make a difference except it won't bottom as much because of a better tune.

  10. #10
    [put something cool here]
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    Quote Originally Posted by zul View Post
    Ever since I got this bike it's been a problem where the rear tire rubs on impact into the seat tube where the der cable.
    Just to clarify: You ride a pre-2011 HD, right? Follow those tips above, but as a matter of fact Ibis reacted to this very issue with changes in frames produced from summer 2011 on: Direct mount derailleur with cable at the side, flatted are in the seat tube.

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