1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
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    Which bearings for my XT crank/bottom bracket?

    Hi, New guy around these parts..

    Recently bought a used Marin 2011 Rift Zone XC8.

    Looove this bike, but as it was used heavily before I bought it, there's wear and tear all over the drivetrain.

    Just replaced the cassette, chain and and changed it from a three chainring to a two chainring setup, up front.

    While removing the crank for installation of the small chainring the bearings in the bottom bracket as well as the crank "tube" showed heavy signs of wear.

    Here's my problem. How do I figure out which bearings to buy? Or do I just buy a new XT M770 bottom bracket?



    I also need a new crank, and I've found a replacement XT set on "chain reaction cycles", but they all come with chainrings installed, I don't need that I just need the crank arm (is that even the right name for it?)

    If anyone could help me out, I'd really appreciate it.


    With regards
    /Anders

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    Last edited by Coach-Z; 06-06-2014 at 01:53 PM. Reason: just learned something new :-D

  2. #2
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    Are you sure that the crankset you're looking to buy doesn't come with the BB as well? Also, whats wrong with the current crank that you need a new one? Spindle bent, crank arms cracked, stripped pedal threads?

  3. #3
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    This is what I'm looking at buying:


    Bottom bracket:
    Shimano XT M770-SLX M660 Bottom Bracket | Chain Reaction Cycles

    Can I get just the bearings or is it sealed unit?

    crankarm
    Shimano XT M770 Triple Chainset | Chain Reaction Cycles

    Can I get it somewhere without the chainrings, don't want to pay for something I don't need.

  4. #4
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    Quote Originally Posted by jetboy23 View Post
    Also, whats wrong with the current crank that you need a new one? Spindle bent, crank arms cracked, stripped pedal threads?
    The tube (spindle??) that goes through the bottom bracket has clear signs of wear... its been shaved down at one end right where it touches the bearing... or thats what it looks like at least.

  5. #5
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    You might be right... this is what the website says:

    Shimano XT M770 9-Speed Chainset Features:

    Hollowtech II crank arms offer unrivalled strength to weight ratio
    SG-X chainrings offer a precise gear shift and are compatible with HyperGlide Chains and cassettes.
    Rigidity and hardness increased with an advanced design due to more separated bearings and wide axis
    9 speed chainrings with ratio 44/32/22
    Supplied with bottom bracket bearings suitable for shell sizes 68 and 73mm
    Weight: 853 gr for the M770 in 175mm
    Please Note: BB included
    68/73mm BB Shell

  6. #6
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    Most of the time, the chainrings come with the crankset as a package. Also, the link you provided states "Please Note: BB included". You don't need to buy any new bearings or a new BB. The crankset will come with it.

  7. #7
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    Sweet... Thanks for your help :-)...

    Sendt fra min GT-N7100 med Tapatalk

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