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When pushing in bearings , grease or loctite?

Discussion in 'Downhill & Freeride' started by soft-compound, May 25, 2014.

  1. soft-compound

    soft-compound Monkey

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    Just wondering what is the best to use when pushing bearings in?
    Grease or loctite for bearings?
    As i know the loctite makes them solid and really hard to get out without heating them.
    But then i dont want to push them in with grease and they start to ovalise or loosen?
     

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  2. Udi

    Udi RM Chief Ornithologist: “I Brake for Birds”

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    There definitely isn't a blanket answer here. The rule of thumb is to play it by tolerances, which in the MTB world vary greatly. You'd generally use retaining compound on a loose bore, anything where you could push the bearing in by hand or with very little effort on a press. For everywhere else a light coat of grease is fine but if there is any concern about movement I'd avoid it.

    There is unfortunately plenty of grey area. For example, a lot of frames (and occasionally even parts) will have out-of-round bearing bores, and thus what is initially judged as a tight press fit could in actual fact be an ovalised bore putting localised loads in the bearing. In these cases I'd attempt to open up the bore a little to prevent premature bearing wear, and use retaining compound to fill the gap and retain the bearing.

    Keep in mind that "loctite" is a misleading term - retaining compound is a specific loctite product (eg. 609) and is not a thread locking compound (eg. 242). The former has a far higher strength.
     
  3. yd35

    yd35 Monkey

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    I propose the addition of an "Ask Udi" pop-up chat window on this forum for when you need a real, helpful response. Basically a Ridemonkey Bat-Signal.
     
  4. DMdh

    DMdh Monkey

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    +1 :rofl:
     
  5. HardtailHack

    HardtailHack used an iron once

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    Yeah if the bore is round I think just the tiniest bit of grease is the way to go.

    I have to work out a way to stop my pressfit BB from moving, it really should be a warranty claim but international postage pretty much rules it out. As I have a spacer tube between the bearings it is stupidly difficult to remove the BB so I may need to use a filler instead of a retainer or a filler then a retainer?
     
  6. Kanye West

    Kanye West 220# bag of hacktastic

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    Press fit = grease.

    Slip fit w/o mechanical retention = retaining compound/get new ****.


    I can't think of any legitimate spot to use retaining compound on a bearing on a bike. That's pretty much emergency use only, and is generally a permanent "solution".
     
  7. nowlan

    nowlan Monkey

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    Just to amplify on Udi's comment. It would not be a regular loctite you use to hold the bearing in place. Its a specific loctite meant to be used when tolerances are out. I had to use it on my Socom Frame a few years back in one area and it worked perfectly. It wasnt very hard to find either from what I remeber.
     
  8. HardtailHack

    HardtailHack used an iron once

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    Regular Loctite will hold a bearing in, it's goes off when there's no oxygen present that's why a loctite bottle is never full.
    I tried medium thread locker on a front hub bearing on a car and it worked fine, would have the proper retainer worked better? Probably.
     
  9. soft-compound

    soft-compound Monkey

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    Yeah i have special type of compound for bearings by delta called 22 which is specifically for bearings.
    So yes i have had bearing were they just push in with your thumb.
    So thanks for the replies everyone as i just wanted to be clear about this.
     
  10. nowlan

    nowlan Monkey

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    On the same topic, do most of the new Carbon Frames use alum inserts to house the bearings?