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  1. #1
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    My Rear Derailleur is broken, looking for a new one

    I ride on Specialized Stumpjumper expert 29" 2008 that came with
    SRAM X0 rear derailleur mid cage and Shimano HG-50, 9-speed, 11-34t.

    Yesterday I managed to break it down and I'm looking to replace it with
    SRAM X9,

    The questions is: Should I stick with the med cage? or go directly to large cage?

    I've been reading the great post about rear derailleurs on this forum.

    Till now I enjoyed smooth shifting and almost no chain drops .

    Thanks

  2. #2
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    Quote Originally Posted by embedded View Post
    I ride on Specialized Stumpjumper expert 29" 2008 that came with
    SRAM X0 rear derailleur mid cage and Shimano HG-50, 9-speed, 11-34t.

    Yesterday I managed to break it down and I'm looking to replace it with
    SRAM X9,

    The questions is: Should I stick with the med cage? or go directly to large cage?

    I've been reading the great post about rear derailleurs on this forum.

    Till now I enjoyed smooth shifting and almost no chain drops .

    Thanks
    If the mid cage X0 worked well, there's no reason to believe that a new X9 mid would work any different. So stick with the mid cage, you like it, you're used to it, and it works for you. Why mess with success?

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  3. #3
    local trails rider
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    A Long cage gets closer to the ground and other things that like to grab it....

    Is your derailer hanger bent or broken too?

    Edit:
    What is your chainring setup? 1, 2 or 3?
    With 3 chainrings, a Long cage makes sure you have enough range to handle all the possible chainring/cog combinations.

    "it IS possible that you are faster or slower than anybody else who is having at least as much if not more or less fun"

  4. #4
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    Quote Originally Posted by perttime View Post
    A Long cage gets closer to the ground and other things that like to grab it....

    Is your derailer hanger bent or broken too?

    Edit:
    What is your chainring setup? 1, 2 or 3?
    With 3 chainrings, a Long cage makes sure you have enough range to handle all the possible chainring/cog combinations.
    My chaining setup is 3.

    I think that what ruined my X0 is bad combination.
    The X0 bent over and was on top of my cassette.

    My concern about the long cage is for chain drops and loose on low gears.

  5. #5
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    You have three chain rings? Usually w/three rings, one needs a long-cage derailleur. What are you ring sizes?

  6. #6
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    Quote Originally Posted by JonathanGennick View Post
    You have three chain rings? Usually w/three rings, one needs a long-cage derailleur. What are you ring sizes?
    22S/32A/44A, 4 bolt 104/64mm

    I don't know why the bike came with medium cage where all the signs point to large cage.

  7. #7
    local trails rider
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    The chainrings are just the usual sizes.

    I did not find SRAM's specifications for what sort of "range" their rear derailers have but - as has been pointed out - long cage is usually considered the safe thing when running 3 chainrings.

    People sometimes run shorter cages to minimize chain slack but then the combination of big ring and big cog is a serious no-no. Those extreme right to extreme left chainring-cog combinations should be avoided anyway, but us being human...

    "it IS possible that you are faster or slower than anybody else who is having at least as much if not more or less fun"

  8. #8
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    That what happened to me, by mistake I did the combination of big ring and big cog.
    I think I'll get a large cage and hope for the best - no chain drops and smooth operation as I had with the mid cage.

  9. #9
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    44+34 - 11+22 = 78 - 33 = 55. Did I get all that math right? I think so. SRAM doesnt seem to list their chain wrap capacities on their website though.

    Edit: Oops! 78 - 33 = 45. And the wrap for an X9 long cage is exactly that, 45 teeth. You need a long cage.

  10. #10
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    Found it. This manual:

    http://www.sram.com/sites/default/fi...nual-rev-a.pdf

    Page 40 shows the chain wrap capacity for a long cage X9 derailleur at 45 teeth. And 78-33=45. So you need a long cage.

  11. #11
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    Quote Originally Posted by jonathangennick View Post
    44+34 - 11+22 = 78 - 33 = 55. Did i get all that math right? I think so. Sram doesnt seem to list their chain wrap capacities on their website though.

    Edit: Oops! 78 - 33 = 45. And the wrap for an x9 long cage is exactly that, 45 teeth. You need a long cage.
    78-33=45

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