gxp to shimano shim adapter

02gf74
02gf74 Posts: 1,171
edited December 2013 in MTB workshop & tech
the left side of gxp chainset is 22 mm whereas right side is 24 mm, shimano chainset being 24 mm both sides.

does anyone know where I can buy the adapter shim to allow the gxp to be fitted to shimano bb bearing?

I have bought a gxp bb which is basically a shimano bb but has the shim fitted on one side - I am after just the shim on its own.

Comments

  • Rightarmbad
    Rightarmbad Posts: 216
    What's wrong with simply using the GXP BB you bought?
    The bearing preload on Shimano and GXP are organised differently.
    Shimano uses the little butterfly cap to set it like a headset, the GXP uses wavy washers and a torque setting.

    They are basically incompatible in every way.
    Just use the proper thing and not jig up a creaky wobbly thing from bits.
  • nicklouse
    nicklouse Posts: 50,675
    Rightarmbad wrote:
    What's wrong with simply using the GXP BB you bought?
    The bearing preload on Shimano and GXP are organised differently.
    Shimano uses the little butterfly cap to set it like a headset, the GXP uses wavy washers and a torque setting.

    They are basically incompatible in every way.
    Just use the proper thing and not jig up a creaky wobbly thing from bits.
    GXP does not use any Preload.

    OP I would not bother.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Rightarmbad
    Rightarmbad Posts: 216
    If the GXP has play, then you change/add a washer or tighten on the high side of the torque spec, so yes it does use a preload, it's just not as obvious as the Shimano system.

    One of the main reasons new GXP BB can seem to fail early is using the high torque spec when it is not required and setting the bearing too tight from new.

    See it all the time.
  • nicklouse
    nicklouse Posts: 50,675
    Rightarmbad wrote:
    If the GXP has play, then you change/add a washer or tighten on the high side of the torque spec, so yes it does use a preload, it's just not as obvious as the Shimano system.

    One of the main reasons new GXP BB can seem to fail early is using the high torque spec when it is not required and setting the bearing too tight from new.

    See it all the time.
    Wrong. GXP HAS NO PRELOAD. It is not held at all on the drive side and clamps on both sides of the inner race on the non drive side. There is no preload on GXP bottom brackets, there are no wavy washers on a GXP.

    There are on other BB types but not on the GXP.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Rightarmbad
    Rightarmbad Posts: 216
    Interesting, because I had an Argon 18 E118 on the stand this afternoon and removed the crank for access to sort out a brake problem and it had a preload washer.
    Argon is a BB86.
    This was not a spacer, but a thin preload washer.

    I also have a new boxed pressfit ceramic XX GXP BB for my Scott Spark RC MTB sitting here, complete with frame spacers, axle spacers and preload shims in the instalation kit.
  • nicklouse
    nicklouse Posts: 50,675
    Rightarmbad wrote:
    Interesting, because I had an Argon 18 E118 on the stand this afternoon and removed the crank for access to sort out a brake problem and it had a preload washer.
    Argon is a BB86.
    This was not a spacer, but a thin preload washer.

    I also have a new boxed pressfit ceramic XX GXP BB for my Scott Spark RC MTB sitting here, complete with frame spacers, axle spacers and preload shims in the instalation kit.
    exactly thast is not GXP is it.


    Again GXP does not use any washers or anything it just clamps on the ND bearing.

    GXP PF "press fit" has a wavy washer as there is nothing to hold the cups in place.

    they are not the same set up at all. wavy washers are also used on other set ups as well.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Rightarmbad
    Rightarmbad Posts: 216
    OP never specified whether pressfit or threaded.
    My Scott is certainly GXP, they only take Shimano pressfit or GXP pressfit.
  • mmacavity
    mmacavity Posts: 781
    http://www.youtube.com/watch?v=NufgDt2zwXk
  • lynnsaunders
    lynnsaunders Posts: 6
    What is missing from the youtube video above is what to do if the drive side crank is not on the chain line from the center of the rear cluster. This can be adjusted by moving the non drive side outward with spacers such as Wheels MFG BB-0.7, 1.8, or 2.5. The drive side typically needs spacers to prevent the chain ring assembly from "floating" on the drive side splines. Wheels MFG sells a pack of 10 2mm spacers with a 24mm ID for this purpose as well as thinner ones.
  • lynnsaunders
    lynnsaunders Posts: 6
    Regarding the above comment, the outboard spacers for the drive side crank that allow alignment to the chain line from the rear cassette are made by Wheel MFG and the part number is SRAM-SPACER-PK
  • JBA
    JBA Posts: 2,852
    @lynnsaunders You didn't look at the dates of the posts above, did you?
    I suspect the OP has sorted it out during the last 7 years.
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Giant Revolt Advanced 2 2019 ¦ Giant Toughtroad SLR 1 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • david37
    david37 Posts: 1,313
    JBA said:

    @lynnsaunders You didn't look at the dates of the posts above, did you?
    I suspect the OP has sorted it out during the last 7 years.

    These bottom brackets can be confusing. the OP may well still be staring with red eyes and his head in his hands.

    Someone tell the op about dub :D
  • steve_sordy
    steve_sordy Posts: 2,453
    edited January 2021
    Never mind Lynn, we've all done it! :)

    Well I sure have!
  • lynnsaunders
    lynnsaunders Posts: 6
    This thread came up in a search for a better understanding of how the GXP BB goes together. I added my comments assuming others would be looking for similar info and hoped the part numbers would be useful.
  • steve_sordy
    steve_sordy Posts: 2,453
    A noble cause. I salute you! :)

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