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I have never worked with bottom brackets or crank arms before. What keys do I need if I want to remove these FSA ones? BBenter image description hereenter image description here

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    Is there any chance you can tell what model it is?
    – Weiwen Ng
    Commented Aug 12, 2021 at 13:33
  • Can you show a photo from the right side? And not just the bottom bracket, but the whole crank. Commented Aug 12, 2021 at 13:43
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    Isn’t that just a self-extracting bolt with a 10mm hex key head? For the bottom bracket itself I think you need a Hollowtech 2 bottom bracket tool/adapter. parktool.com/blog/repair-help/…
    – Michael
    Commented Aug 12, 2021 at 13:56
  • @WeiwenNg the model seems to be Omega. Sorry, should have thought about that from the start.
    – Ivan
    Commented Aug 12, 2021 at 14:09
  • @VladimirF I have now attached the right side photo.
    – Ivan
    Commented Aug 12, 2021 at 14:10

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There are some general principles for removing cranksets with the spindle integrated into the crank. I'm not sure if there is a generic term for this type of crank, as opposed to older square taper, ISIS, or Octalink cranks where the spindle is integrated into the bottom bracket.

First, you clearly have a fastening bolt in the non-drive side. Usually, this type of bolt takes an 8mm or 10mm allen key. Undo the bolt, then slide each crankarm out of the bottom bracket - but note point two first. Sometimes you access the bolt from the drive side (e.g. Quarq and some SRAM cranks). Shimano cranks lack a main fastening bolt per se - there's a splined top cap that you would remove with the proprietary tool, then you undo the 2x 5mm bolts that clamp the non-drive side arm to the spindle (in a similar fashion as removing a threadless stem).

Second, many cranks have some sort of system to maintain bearing preload. Preload is a term for how much side load there is on the bearings. In some cranks, there's some sort of system to push one or both arms outwards. The FSA Omega (link to the parts documentation here) has a wave washer on the non-drive side. Campagnolo does similar, SRAM and Quarq have an expanding collar on the non-drive side plus a set of spacers. Shimano's system doesn't need this feature. Whatever the case, take note of what you have and retain it for reinstallation. If you had a collar (you don't), you'd need to loosen it and remove it.

Third, you can now deal with the bottom bracket. I believe that the FSA BB you have uses a standard tool that uses the same spline pattern as Shimano's BBs. Shimano was the first major drivetrain manufacturer to release an integrated crankset with outboard BBs, so their spline pattern may have stuck with at least some aftermarket manufacturers. The compatibility description for the Park Tool BBT-9 claims compatibility with Shimano and a number of other manufacturers including FSA. Press fit BBs are another story.

For installation, reverse this order of operations, but do pay attention to the preload system. I believe that this FSA crank should be pretty simple, just put the wave washer on the non-drive side when you are installing the non-drive arm. Campagnolo cranks have a wave washer like FSA, plus an additional bearing retaining clip on one side. For SRAM and Quarq cranks, you need to pay attention to which spacers and how many to use, and on which side of the crank. This varies by BB shell type. Additionally, you need to manually set the preload using the preload ring.

In all cases, do be aware that many commentators upload videos to YouTube. You can try to search for a specific model or type of crankset. This may be complicated with FSA, because they have a number of models, and I'm not sure if the procedures are all identical (but I'm not familiar with FSA's whole lineup). I think that all SRAM/Quarq (same parent company) cranks use the same procedure (but I'm not 100% certain if the older GXP spindle cranks conform); Campagnolo has two standards (Power Torque and Ultra Torque) that should be broadly similar but may have some particulars differing; all Shimano non-square and non-Octalink cranks should be the same.

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  • To tack onto this, threaded BB cups can have one of a few diameters for the 16-notch splined ring (which interfaces with the tool): 39 mm, 44 mm, and 48.5 mm (that I know of; there is also apparently an 8-notch spline pattern). You can find single tools that have two openings. There are flat tools (like the Park tool linked above) and socket-style tools. The socket tools are easier to use in my experience.
    – Adam Rice
    Commented Aug 12, 2021 at 15:44
  • @Adam Rice There is also 41mm for Ultegra/XT BB
    – MaplePanda
    Commented Aug 12, 2021 at 18:26
  • Note that the latest Shimano XTR cranks have moved to a single bolt type retention system, so the Shimano 2-bolt system is no longer universally the case.
    – MaplePanda
    Commented Aug 12, 2021 at 18:27
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    @MaplePanda I love standards. Can't get enough of them.
    – Adam Rice
    Commented Aug 12, 2021 at 19:42

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