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  1. #1
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    homemade crank flex fixes?

    im a big dude at 280 and im riding a GT avalanche 3.0

    the first crank lasted a couple days (suntour XCT) then it started to rub in the hard gears.


    So i take it back to the shop (the bike only being two days old) and paying for a new crank installed.

    New crank is a truvativ five D and it is rubbing within the first couple hours of ridding.

    im either going to take the bike back for a full refund or fix it myself somehow.

    So any of you guys/girls have a crank flex fix that would like to share it with me?


    i have been thinking of maybe adding little washers on the spider at the parts whee its rubbing but ill wait for some suggestions.

    Thanks

  2. #2
    Hardbooter
    Reputation: KingCrimson's Avatar
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    Specifically where is it rubbing? Are the cranks bent inwards and hitting the chainstays?

  3. #3
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    it is rubbing in front 3 back 7,8 gears

    the arms themselves are straight.

    It rubs when im pedalling "hard" . When my right foot is on the downstroke the chainring is rubbing on the front derailleur cage.

    i mean i dont even have to pedal hard to get it to rub.. im stumped

    i feel like asking for my money back and putting more money down on something better.

  4. #4
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    Generally, chainrings aren't perfectly concentric, and yours may be a little bit out of true so to speak.

    My guess is the force you're putting on the ring is amplifying that flaw. I'd assume they reused your chainrings when they replaced the crankset. Tell them to throw a new large chainring on the bike.

  5. #5
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    its a whole new set of chainrings along with a new rear cassette. Now the old chainrings that were on the suntour crank were pretty bent out of true. The current truvativ ones look pretty true but its still rubbing or flexing (whichever ay you like to look at it)

  6. #6
    Shortcutting Hikabiker
    Reputation: Acme54321's Avatar
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    Quit buying crappy cranks. You are 280lbs, anything like that is going to flex. You need something external bearing with a big old axle. Try some XTs. Or even LX.
    "Listen here you beautiful *****, I'm about to **** you up with some truth"

  7. #7
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    I don't know why the shop sold you the Five D's, you should get away from a square taper BB and go with a two piece external BB crankset, best bang for the buck is Shimano LX Hollowtech II

  8. #8
    All 26.5" all the time!
    Reputation: Zanetti's Avatar
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    Quote Originally Posted by bigCgt
    im a big dude at 280 and...

    the first crank lasted a couple days (suntour XCT) then it started to rub in the hard gears.


    So i take it back to the shop (the bike only being two days old) and paying for a new crank installed.

    New crank is a truvativ five D and it is rubbing within the first couple hours....

    Two words -- tubular cro-moly. (Profile Racing and copies)

    At your weight, it's easy to determine if the cranks will rub. If the arms are made of aluminum, then yes, they will flex and rub.

    I weigh 110 lbs less than you, but at that weight even I can tell the difference between cro-mo cranks and wimpy aluminum ones.

  9. #9
    ups and downs
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    I'd even look for a set of Hone cranks on clearance at that weight.

  10. #10
    ≈ > ♥
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    Get Saints, or Profile Racing chromo's.

    You won't have to worry about breaking anything after that...

    Jenson has the single Saints on for $150. Put your rings on those, and you're set.

  11. #11
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    thanks for all the answers guys

    guess what it was? the god damn front derailleur being bent from the factory.. bent it out some and bam its fine now

  12. #12
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    are you sure it wasnt just out of adjustment and now you bent it?

  13. #13
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    yeah because it wouldnt adjust anymore without the chain falling off.


    so far so good.. no rubbing after he bent the front derailleur out more

  14. #14
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    It might not have been lined up properly on the seat tube...

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