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  1. #1
    goes well with tea
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    Outboard bearings and facing BB's

    I just installed a brand spanking new MegaExo (it's one of the style where the bearings sit outside the BB shell, thus it's supposedly a lot stiffer, but also apparently very sensitive to axial loads).

    The cranks, with no chain connected, do not spin freely at all. I can give 'em a nice push, and they stop spinning within a single rotation. My old square taper BB with semi-rusty cartridge-style ball bearings (you know the $15 kind) spun way better.

    In reading this: http://www.velonews.com/tech/report/...s/11607.0.html (scroll down to "Faced, spaced, or both") I learned that should visit a bike shop at some point and get by BB shell faced so I don't damage my bearings, and take a little of the friction out of the system. It's pretty obvious that my BB shell *isn't* faced since I can even see paint from the frame that has dripped down onto the BB shell. No way that can be there and everything still be perfectly aligned right?

    So my question: Do you guys think it's ok to ride the bike for a while, or should I uninstall the crank and BB immediately and go get the BB shell faced (or risk destroying my BB). I'm not sure how critical of a problem this is.

  2. #2
    mtbr member
    Reputation: Joules's Avatar
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    it will accelerate wear on the bearings, they won't suddenly fail after 5 minutes or catch fire or anything. If you rode it for a couple months that would be one thing, a couple of days nothing really to worry about.

  3. #3
    mtbr member
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    The critical thing is that the shell is faced to the threads in the BB. Many of the facing tools i've seen don't use the threads to centre so IMO not worth doing. Worth checking what type of tool your LBS use before getting this done. Otherwise, you might as well just scrape the paint off yourself.

  4. #4
    Old school BMXer
    Reputation: Blaster1200's Avatar
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    The bearings and seals are probably simply just new and tight. I'd ride it.

  5. #5
    3 "fiddy" for short
    Reputation: be350ka's Avatar
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    check your bearing preload.

  6. #6
    thecentralscrutinizer
    Reputation: mopartodd's Avatar
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    Quote Originally Posted by Joules
    they won't suddenly fail after 5 minutes or catch fire or anything. If
    I don't know about that....I had a set of RF bearing catch fire just that way.
    2014 Giant Anthem 27.5
    2013 DeVinci Leo SL
    2009 SE Racing SoCal Flyer
    2008 SE Racing lil Ripper
    2003 TiSport Gman

  7. #7
    goes well with tea
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    Quote Originally Posted by mopartodd
    I don't know about that....I had a set of RF bearing catch fire just that way.
    Haha. Quit using petroleum jelly to grease your bearings.

    But seriously, thanks for the responses. I think the consensus here is for me to take it to a bike shop and have some professionals take a look.

  8. #8
    thecentralscrutinizer
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    Quote Originally Posted by scone
    Haha. Quit using petroleum jelly to grease your bearings.

    But seriously, thanks for the responses. I think the consensus here is for me to take it to a bike shop and have some professionals take a look.
    That's the best thing. I did go through 2 sets of RF bearing do in part to not having the facing done.
    2014 Giant Anthem 27.5
    2013 DeVinci Leo SL
    2009 SE Racing SoCal Flyer
    2008 SE Racing lil Ripper
    2003 TiSport Gman

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