I haven't been able to find a bottom bracket tool for this specific spline count/pattern. It looks like it might fit a standard 20-spline one, but I'm not sure since there are actually only 16, but with larger gaps in between groups of 4:

enter image description here

  • Apologies if I am saying the obvious but could you buy the cheapest possible 20 tooth tool just to check the pattern, and if it fits then buy a proper one? Only the male bits are missing in your photo so I can't see an obvious reason it wouldn't fit.
    – pateksan
    Sep 27, 2020 at 21:04
  • 2
    I wanted to make sure that this isn't actually a different pattern. Yes, it does seem like a 20 tooth tool might work, but can't really tell for sure whether the spacing between the 4-groups really is equivalent to 2 normal spacings + 1 spline. That's what I'll be trying anyway if no-one else here points out otherwise - I just didn't want to wait a couple days for the tool just to find that it doesn't fit, and then have to get another one. Plus, someone else might be wondering the same at some point, so thought it would be useful to document through this question :).
    – Cody-G-G
    Sep 27, 2020 at 22:22
  • Get some Silly Putty and make a mold of the teeth. See if it matches when you span a gap. Sep 27, 2020 at 22:34
  • Are there any identifying marks on it?
    – mikes
    Sep 27, 2020 at 23:30
  • 1
    @Criggie yes, that's a fair point, I will most definitely need it in the future anyway.
    – Cody-G-G
    Sep 29, 2020 at 9:23

1 Answer 1


It's just the regular old 20-spline cartridge type tool, i.e. Park BBT-22. I have seen a few like this, although I don't really know what the deal is with them.

While there are now an enormous number of outboard type BB tool spline patterns, internal cartridge BBs pretty much exclusively use either the Shimano-originated 20-spline tools or the smaller Campy spline pattern.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.