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  1. #1
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    Idea! how to convert to 2x8 drivetrain?

    My Cannondale is from 1996, fully rigid, non-disc brakes. I'm wanting to upgrade the crank to 165mm & the bottom bracket, but all I see online are 2x9 & 2x10 cranks. Are cranks really manufactured for certain gear systems like 9 speed & 10 speed? I thought any mtb crank can be used, regardless of your gear system. Also wanting to upgrade front & rear derailleurs. Current components below.

    shifters: XTR M910, 8 speed
    cassette: XT CS-M737, 8 speed, 11-28
    crank: Shimano Altus 170mm, chainrings 24/32/38
    (
    chainrings are permanently factory attached to the crank)

    bottom bracket: Shimano BB-LP26
    bb shell width: 68mm English (square-tapered)
    chain: KMC X9SL Superlite 9 Speed Chain Ti Nitrate " x 11/128"
    front derailleur: Shimano AceraX top-swing, bottom-pull
    rear derailleur: Shimano AceraX
    wheels: Mavic Crossride UB 26" 2013
    frame size: 16 inch

    If I had a better triple chainring crank & removed the granny gear, would I need a bashguard?

    Would I need new front/rear derailleurs on a 2x8 drivetrain?


    When looking at online bike shops for cranks, it asks for BB Type:
    68MM / 73MM
    83MM
    External Cup
    PF30 83MM
    Standard

    No other types will work?

    Thank you very much

  2. #2
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    8 and 9 speed crank sets/rings are the same.

    The crank arms on a (Shimano) 10spd and 9 spd crank set are the same. 10spd rings are different to 9 spd rings. When 10spd rings are mounted on a crank set they are slightly closer together than 9 spd rings will be. Many on here claim a 10spd crankset/rings work fine on a 9spd system.

    10spd mixed with 9 spd there is a big "sticky" thread on it.
    Duct tape iz like teh Force. It has a Lite side and a Dark side and it holdz the Universe together.

  3. #3
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    9spd shimano F&R derailleurs will work with your 8 speed shimano shifters.

    To fit a bash guard you normally mount it in the big ring position on the crankset.

    You can remove your square taper bottom bracket and fit a external type bottom bracket. You might need to get the frame "faced" at a LBS.

    A 68mm bottom bracket uses 3 spacers and a 73mm uses only 1. You will most likely have a 68mm BB

    A lot of information can be found at Sheldon Browns site.
    also have a read here
    Repair Help and Education
    Duct tape iz like teh Force. It has a Lite side and a Dark side and it holdz the Universe together.

  4. #4
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    Quote Originally Posted by mitzikatzi View Post
    8 and 9 speed crank sets/rings are the same.

    The crank arms on a (Shimano) 10spd and 9 spd crank set are the same. 10spd rings are different to 9 spd rings. When 10spd rings are mounted on a crank set they are slightly closer together than 9 spd rings will be. Many on here claim a 10spd crankset/rings work fine on a 9spd system.

    10spd mixed with 9 spd there is a big "sticky" thread on it.
    Ahh i see@closer together

    Originally my bike was a 7 speed. Still have the stock Altus crank. I can really buy a 2x9 crank & all will be compatible?

  5. #5
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    yes
    Duct tape iz like teh Force. It has a Lite side and a Dark side and it holdz the Universe together.

  6. #6
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    Quote Originally Posted by mitzikatzi View Post
    9spd shimano F&R derailleurs will work with your 8 speed shimano shifters.

    To fit a bash guard you normally mount it in the big ring position on the crankset.

    You can remove your square taper bottom bracket and fit a external type bottom bracket. You might need to get the frame "faced" at a LBS.

    A 68mm bottom bracket uses 3 spacers and a 73mm uses only 1. You will most likely have a 68mm BB

    A lot of information can be found at Sheldon Browns site.
    also have a read here
    Repair Help and Education
    Tyvm mitzikatzi@9spd shimano F&R derailleurs will work with your 8 speed shimano shifters.

    And ty for the education. I'm saving that link in my favorites

  7. #7
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    Idea!

    Understanding the new component standards can get really confusing. To help simplify things for me, will this crank work on my bike? I chose 165mm with 68/73mm BB
    Race Face Atlas Mountain Bike Crankset : Amazon.com : Sports & Outdoors

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