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  1. #1
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    FSA MegaExo chainrings have broke-off tips, with 500 miles

    Hi,

    I have a new road bike the came with an FSA MegaExo crank set, 50/39/32T, 130mm. Recently I noticed that about 1/3 of the teeth on the 50/30 rings have their tips broken off. The amount of broke off is a bout 1/4 - 1/3 of the tooth height. The bike has about 500 miles on it. The rest of the rings do not show much wear off, cogs (Shimano Ultegra) look good too. The chain, a Shimano 105 CN5600 looks fine as well.

    Does this have to do with shifting gears while climbing/starting? Most of my riding is on flat roads and I do not do much hard starting. Has this happened to any of you? What could have caused such a quick wear off? Do I need to replace the rings now?

    Thanks,
    -md009003

  2. #2
    AEO
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    those are shaped and ramped teeth to aid in shifting, yes.
    Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
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  3. #3
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    Quote Originally Posted by AEO View Post
    those are shaped and ramped teeth to aid in shifting, yes.
    The teeth are made that way? In other words, what I saw now is what I always had from the beginning? That sounds plausible, even though the little ring (30T) doesn't appear to have such teeth arrangement.

  4. #4
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    maybe bad shifting habits.?

  5. #5
    Pwnerer Wordbiker's Avatar
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    Quote Originally Posted by MadBuddha1 View Post
    maybe bad shifting habits.?
    No, AEO has it right.

    The small ring doesn't need engineered ramps and pickup teeth as the chain doesn't shift up to it, nor does the chain need release gates to shift down. On a triple setup only the middle and large rings will have shifting aids.
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  6. #6
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    Quote Originally Posted by Wordbiker View Post
    No, AEO has it right.

    The small ring doesn't need engineered ramps and pickup teeth as the chain doesn't shift up to it, nor does the chain need release gates to shift down. On a triple setup only the middle and large rings will have shifting aids.
    Thanks for confirming AEO's statement.

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