New BB & gap

SCR Pedro
SCR Pedro Posts: 912
edited April 2009 in Workshop
Hey there,

I have put a new square taper BB on to my bike. It is the same size as the previous one, but this time there is a 1mm gap between the BB shell and the outer ring which the BB tool connects to.

It has threaded properly so I can't understand why it has done this. Will it be a problem, or should I just ride on it?

Cheers
Pedro
Giant TCR Advanced II - Reviewed on my homepage
Giant TCR Alliance Zero
BMC teammachineSLR03
The Departed
Giant SCR2
Canyon Roadlite
Specialized Allez
Some other junk...

Comments

  • maddog 2
    maddog 2 Posts: 8,114
    not quite sure what the "outer ring which the BB tool connects to" is but the BB unit itself should tighten up to the frame shell on the driveside so it is flush. On the non-driveside then the BB cup should take up any play in the BB but often doesn't tighten all the way in, especially the plastic cups. As lomg as the BB is snug, it's fine.

    The other possibility is that maybe the BB shell has some damaged threads or even the BB unit is hitting the bolt that often holds the cable guides in place, under the shell?
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • nicklouse
    nicklouse Posts: 50,675
    back off the left hand sleeve.

    tighten the drive side home (no gap) and then tighten the left hand sleeve.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • SCR Pedro
    SCR Pedro Posts: 912
    Thanks guys. I'm going to re-do the whole thing.

    My terminology sucks. But if you look at the diagram here, the part I am talking about is the fixed flange (the collar of the sleeve).

    So do you think I should use the metal sleeve that came off the last BB, instead of the new plastic one?

    Cheers
    Pedro
    Giant TCR Advanced II - Reviewed on my homepage
    Giant TCR Alliance Zero
    BMC teammachineSLR03
    The Departed
    Giant SCR2
    Canyon Roadlite
    Specialized Allez
    Some other junk...
  • nicklouse
    nicklouse Posts: 50,675
    makes little difference. i have swapped between both
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • SCR Pedro
    SCR Pedro Posts: 912
    Thanks. I'll mess about with both until I get it right.

    Then I can sort out the shambles that is my front derailleur...

    Pedro
    Giant TCR Advanced II - Reviewed on my homepage
    Giant TCR Alliance Zero
    BMC teammachineSLR03
    The Departed
    Giant SCR2
    Canyon Roadlite
    Specialized Allez
    Some other junk...
  • SCR Pedro
    SCR Pedro Posts: 912
    By the way, I've fixed this problem. I took the bottom bracket out, installed the right side of it first, then ditched the plastic sleeve for the alu' one.

    All is well again.

    Cheers
    PEdreo
    Giant TCR Advanced II - Reviewed on my homepage
    Giant TCR Alliance Zero
    BMC teammachineSLR03
    The Departed
    Giant SCR2
    Canyon Roadlite
    Specialized Allez
    Some other junk...
  • maddog 2
    maddog 2 Posts: 8,114
    the alu cup certainly goes in easier than the placky one.

    what I used to do with the placky one is:

    - tighten BB unit in flush on the driveside
    - tighten in the placky cup, until it was fairly snug but not tight
    - undo the BB unit about 1 turn (IIRC)
    - tighten the placky cup 1 turn
    - tighten the BB unit flush again

    This way, the unit is tight against the placky cup, but you use the metal BB unit to do the tightening, not the placky cup, which is pretty weak.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer

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