Fitted xtr crank and bb. Hope its right?

steve9uk
steve9uk Posts: 126
edited April 2011 in MTB workshop & tech
Hi Guys.
I fitted my new xtr crank and bb today and followed everything by the book. Torque here, grease this tighten that etc
When its was all assembled i spun the crank and it turns ok but does not spin free. There is a little resistance there.
What i would like to know is this because its new and needs bedding in or should it spin freely straight away?

I would appreciate your ideas.
Thanks

Steve

Comments

  • supersonic
    supersonic Posts: 82,708
    There will always be a little resistance due to the nature of the seals and bearings, but they tend to loosen up. The system works rather like a headset: so you need to makesure the adjustment bolt is not too tight, but not too loose that there is play.
  • steve9uk
    steve9uk Posts: 126
    Thanks supersonic.
    as i say everything was tourqued up and greased up. The crank does run smooth and there is no play just a little resistance.
    My heart was in my mouth as i thought i did it wrong. Think i leave it to the lbs in furture :)
  • Anonymous
    Anonymous Posts: 79,667
    A properly greased bearing should not "spin free" unless there is a significant mass on it, supplying inertia.
    As long as the rotation is smooth, it's fine.
  • joshtp
    joshtp Posts: 3,966
    why leave it to the LBS? you did it, and did it right... getting someone else to do it is just throwing money at the fire..
    I like bikes and stuff
  • supersonic
    supersonic Posts: 82,708
    The frame was faced though?
  • steve9uk
    steve9uk Posts: 126
    Thanks guys.
    I'll be able to sleep now tonight :D
  • steve9uk
    steve9uk Posts: 126
    Faced? :?
  • supersonic
    supersonic Posts: 82,708
    Ah. If the bottom bracket shell has not been 'faced' (this makes sure that the shell surfaces are flat and parallel so the bearing cups are aligned) then it is very possible you will wear the bearings down a lot more quickly. It could cause it to feel tighter too.
  • steve9uk
    steve9uk Posts: 126
    is this a big expensive job to be done? its a carbon frame also
  • supersonic
    supersonic Posts: 82,708
    15 quid or so. But worth doing.
  • steve9uk
    steve9uk Posts: 126
    Thanks super.
    I'll think i'll take your advice. I'll book it into my lbs. i hope it will be ok for a few weeks as they are busy until 16th april.

    Thanks for all the good advice guys

    Steve
  • cooldad
    cooldad Posts: 32,599
    Something I always wonder (external bb's are fairly new to me) if the bike came with an external bb, I would have assumed the frame came out of the factory faced?
    Just changed mine after about 18 months of hard riding, wasn't bad but I managed to trash the non drive bearing cover (plastic top hat shaped jobby) digging around to see what was inside and whether I could open the bearing and add some grease. (Worked fine on the drive side).
    I was just changing the cassette and chain, but decided to fiddle.
    Ended up with a new crankset as well just for the hell of it, but to get to the point, I'd had no problems with the bearings except for gunk, so assumed (correctly I hope) I could just fit the new bb.
    I don't do smileys.

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  • Anonymous
    Anonymous Posts: 79,667
    cooldad wrote:
    Something I always wonder (external bb's are fairly new to me) if the bike came with an external bb, I would have assumed the frame came out of the factory faced?
    You would hope so, yes, but sadly it's not always the case. QC at some manufacturers / shops is not the best, unfortunately.

    (as a perfect example of bike manufacturers doing something they shouldn't, consider Orange selling tons of bikes with Hope aluminium freehubs, and cheap non spidered cassettes)
  • steve9uk
    steve9uk Posts: 126
    Well i'm going from xt deore hollowtech 2 to xtr. so i presume nothing has changed?
    Like for like. same bb and same length etc.
    Would i still need it faced?

    Thanks guys
  • cooldad
    cooldad Posts: 32,599
    But Orange are Speshul, like using old bridges to build frames, so they can be excused.

    Anyway the original lasted long enough, if the new one lasts as long I guess it's ok, if not they are cheap enough.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • cooldad
    cooldad Posts: 32,599
    steve9uk wrote:
    Well i'm going from xt deore hollowtech 2 to xtr. so i presume nothing has changed?
    Like for like. same bb and same length etc.
    Would i still need it faced?

    Thanks guys

    As Yeehaa said, maybe, maybe not.
    I stuck a Deore on so it's a cheap replacement, XTR - ouch if it only lasts a few rides.

    My BB was nice and shiny, with no paint or anything so hopefully it was ok.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • steve9uk
    steve9uk Posts: 126
    Think i might let the lbs have a look? peace of mind. :?