External BB shell spacer, which side?

dazzawazza
dazzawazza Posts: 462
edited March 2009 in Workshop
As per installation instructions I have installed the shell spacer on the left hand (non drive) side BB cup. This is a FSA MegExo Bottom Bracket with a 10spd Gossomer compact chainset.
The problem I have is that when in the small-small gear combination the chain is rubbing on the inside of the largest chainring. This rub doesn’t stop until I’ve changed to the 4th smallest cog on the cassette.
Now it makes sense to me that the spacer should actually be on the right hand (drive) side of the BB so that the chainset is further away from the frame? Is this a correct assumption?

I’m not worried about the chain rubbing when on the smallest cog, but not the 3rd smallest.

Comments

  • nicklouse
    nicklouse Posts: 50,675
    i am supprised that you have a spacer with a road set up.

    what is the BB part number?

    and the cranks the Plain gossamer or the pro version?
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  • dazzawazza
    dazzawazza Posts: 462
    It's either a BB-6000 or BB-4000, I can only guess from the instructions as there are no markings on the BB. The cups are a copper colour and I think the chainset is the plain Gossamer (it's alloy).
    The spacer is only thin rubber, but probably wide enough to cause the rubbing when on the non drive side and the 3rd smallest cog. The frame is a small Planet-X Pro Carbon.
    Should I remove the spacer altogether?
  • nicklouse
    nicklouse Posts: 50,675
    copper as in brown?

    sounds like you may have a MTB triple bb set. ( it is the spacer that makes me think this)

    But to be honest i have kept away from any of the FSA bb stuff as they have made it too complex.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • redddraggon
    redddraggon Posts: 10,862
    dazzawazza wrote:
    This rub doesn’t stop until I’ve changed to the 4th smallest cog on the cassette.

    That's pretty much normal when using a 50/34 setup to be honest. The shorter the chainstays the worse it is, and I know you got a small P-X.
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  • dazzawazza
    dazzawazza Posts: 462
    It is a bit odd that it has the brown MTB cups, but there were no larger alloy shell spacers in the box (for MTB), only a thin rubber spacer.
    I think I'm going to leave it as I have just read at the end of the instructions that there can be contact with the large chainring when on the last three cassette cogs.
    Another concern I have is that the turning of the cranks is quite stiff. Not as free as the Octalink and square taper BBs on my other bikes. Is this an external BB trait that will free up after putting some miles on? Or could it be the rubber spacer causing the stiffness, in which case I should remove it?
  • redddraggon
    redddraggon Posts: 10,862
    dazzawazza wrote:
    Another concern I have is that the turning of the cranks is quite stiff. Not as free as the Octalink and square taper BBs on my other bikes.

    That's quite normal, I had the same with Gossamer crankset when I installed it.
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  • dazzawazza
    dazzawazza Posts: 462
    The shorter the chainstays the worse it is, and I know you got a small P-X.

    Thought so :shock:
  • topdude
    topdude Posts: 1,557
    Hi, i have just fitted an FSA Gossamer MegaExo compact this weekend to replace my old Tiagra compact and i have noticed the same problems as you :(

    I think the colour of the BB is called "Titanium" sort of brownish silver so should be the correct one for your chainset.

    I also find the chain rubs the inside of the large ring on the last three cogs as the large ring is quite fat compared to the old Tiagra one. I didn't fit the spacer as according to the instructions it is for the Carbon chainset and goes on the non drive side. It might help a little to fit it on the drive side cup or maybe a slightly thicker alloy spacer would be better :?:

    And yes, the cranks are quite stiff to turn by hand, probably due to tight seals in the bearing cups.

    Anyway i'm off to give it a test ride today (nice and sunny here in Hampshire) :D
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  • topdude
    topdude Posts: 1,557
    Ok, test ride went well, i found i could use the first 6 rear cogs while on the inner 34 chainring without the chain rubbing on the large ring. When changing to No 7 the rubbing starts but is just about bearable. Nos 8 & 9 are definitely not usable.
    Other than that it all ran quiet and smooth, so very pleased :D
    He is not the messiah, he is a very naughty boy !!
  • dazzawazza wrote:
    It's either a BB-6000 or BB-4000, I can only guess from the instructions as there are no markings on the BB. The cups are a copper colour and I think the chainset is the plain Gossamer (it's alloy).

    dazza - check out this page.

    http://www.fullspeedahead.com/downloadf ... on2007.pdf

    sounds like you do have the 6000 though.

    just installed one of these myself this weekend. interesting to hear others having issues. the instructions actually say that you should install an o-ring on either side of the bb but mine only came with one which i installed on the drive side. cranks dont turn very easily but hoping they will loosen up as per red dragons input.