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  1. #1
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    Fox RPL Mounting Issue

    I have a '05 XC104 that I have been upgrading lately. Just put on a new TORA 318 and recently got a smoking deal on a RPL to replace the stock coil spring shock. My issue is that after ordering the part #'s listed in the Fox shock thread the top spacer is perfect but the bottom spacer is too short. I hope the pics come across clear enough, my question is can I simply use something (aluminum tube cut to length, etc) to fill the gap or do I risk damage to shock?


  2. #2
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    No
    Get the right size spacers.
    The spacers keep the shock loads from bending the bolt.
    You risk breaking the bolt and/or ruining your frame. The spacers bridge the load out to the side plates. The bolt should only take shear loads.

    As it is now the bolt is in bending load case which causes much higher stress in the bolt and in your frame.
    Buying the right size spacers is cheaper than a broken bike and injuries.

  3. #3
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    Quote Originally Posted by mtnbeer
    No
    Get the right size spacers.
    The spacers keep the shock loads from bending the bolt.
    You risk breaking the bolt and/or ruining your frame. The spacers bridge the load out to the side plates. The bolt should only take shear loads.

    As it is now the bolt is in bending load case which causes much higher stress in the bolt and in your frame.
    Buying the right size spacers is cheaper than a broken bike and injuries.
    I'm not sure I agree with your description. To me, the spacers keep the shock centered so there are flat surfaces touching between the bolt/shock to spread the load. If it weren't centered then the force would be concentracted at one point where the edge of the shock is hitting.

    For the spacers to transfer any load, they would have to be compressed between the outer frame plates.

    Regardless, you need to space it properly.
    KHS
    Motobecane
    Fisher
    Kona

  4. #4
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    Revised part of my post. New parts in CAPS

    The spacers bridge the load out ALMOST to the side plates. THE BOLT THEN TRANSFERS THIS LOAD IN SHEAR TO THE SIDE PLATES. The bolt should only take shear loads. CLEARANCE BETWEEN THE SPACERS AND SIDE PLATES SHOULD BE MINIMIZED. LARGER THE GAP, THE THE LARGER THE BENDING STRESS.

    Ideally, the bolt should be in what the engineering books call double shear loading. Look it up.

  5. #5
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    Quote Originally Posted by mtnbeer
    Revised part of my post. New parts in CAPS

    The spacers bridge the load out ALMOST to the side plates. THE BOLT THEN TRANSFERS THIS LOAD IN SHEAR TO THE SIDE PLATES. The bolt should only take shear loads. CLEARANCE BETWEEN THE SPACERS AND SIDE PLATES SHOULD BE MINIMIZED. LARGER THE GAP, THE THE LARGER THE BENDING STRESS.

    Ideally, the bolt should be in what the engineering books call double shear loading. Look it up.
    Gotcha, that makes sense.
    KHS
    Motobecane
    Fisher
    Kona

  6. #6
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    That was my issue. evidently the old shock has stressed the side plates by coming loose. i "massaged" the bent plate back and got wider spacers/bushings at the lbs today. All issues solved, my concern was the sheering forces as well. The old shock had cheap plastic spacers on either side of the coil and that was it.

    Thanks for the help.

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