Do I Need A Crank Arm Extractor To Replace A Chainring?

EViS
EViS Posts: 48
edited October 2011 in MTB workshop & tech
I need to replace a Shimano SLX chainring. Will I need a crank-arm extractor for this? (it's been a while since I fiddled with bikes)

Comments

  • warpcow
    warpcow Posts: 1,448
    Yes, if it's the granny. No otherwise.

    It's not a 'crank extractor' you need (if you do), it's a hollowtech BB tool.
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  • EViS
    EViS Posts: 48
    Hmmm, I need to replace the outer chainring as per photo below. Do I need this tool (or this) as opposed to a 'crank extractor' tool?

    crank01.jpg
  • gilesjuk
    gilesjuk Posts: 340
    EViS wrote:
    Hmmm, I need to replace the outer chainring as per photo below. Do I need this tool as opposed to a 'crank extractor' tool?

    You won't need it for the outer ring. But will do for the granny ring.

    Such a tool is available at Halfords for less:

    http://www.halfords.com/webapp/wcs/stor ... yId_242558

    You only need the black plastic disc unless you're intending to replace the cups too.

    The plastic disc is used to put tension back onto the bearings when refitting. It is the pinch bolt on the crank that keeps them in place.
  • heliphil
    heliphil Posts: 59
    neither - you just need the tool ( could be allen key) to take off the chain rings - its easier with the crank off but either way its not difficult
  • EViS
    EViS Posts: 48
    edited October 2011
    Right, so to confirm; despite only wanting to replace the outer ring, I will still need a hollowtech BB tool, correct?
    heliphil wrote:
    neither - you just need the tool ( could be allen key) to take off the chain rings - its easier with the crank off but either way its not difficult

    Oh, so I don't need any tools other than an allen/hex key? Confused now chaps :?.
  • John Stevenson
    John Stevenson Posts: 962
    To remove the outer ring, you just need whatever tool is necessary to unbolt it from the spider. That's probably a 5mm Allen key.

    You do not need to take the cranks off, so you don't need a Hollowtech remover.
    John Stevenson
  • The Rookie
    The Rookie Posts: 27,812
    As stated, to replace the outer ring you just need an allen key, were you to want to replace the middle ring you MAY need to remove the cranks - but you may not (depends on rings/frame and cranks, to do the inner you DO need to remove the cranks.

    Simon
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • EViS
    EViS Posts: 48
    Great, thanks for confirming :).

    Whilst being on this topic, would I ever require a crank arm-extractor if I were to replace my SLX cranks?
  • schweiz
    schweiz Posts: 1,644
    You don't need a crank arm extractor/puller for Hollowtech II cranks. Just undo the pre-tension bolt then both pinch bolts on the non-drive side and the crank will come off easily. The drive side pulls through the BB shell.

    There was a video on BR a couple of weeks back IIRC. But be careful with the video. He talks about having a good long lever on the tool he does the pre-load bolt up with after re-fitting as if this is a good thing. It needs somthing like 1.5 Nm which is finger tight using the shimano black plastic disc.
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  • EViS
    EViS Posts: 48
    Thank you for all the responses chaps. This modern world of air suspension, hydraulic disk brakes and new tools is all very new to me :).

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