FSA chainring removal - what size the nuts??

pep.fermi
pep.fermi Posts: 330
edited May 2023 in Workshop
Just wanted to remove my front chainring, FSA, on my Cannondale Synapse.
Found out the metric Allen keys don't fit: 4mm too big, 3mm too small.
No wonder, after all Cannondale is American (I guess FSA too), so they probably use metric sizes.
So I tried imperial Allen keys, 5/32 (=3.97mm) too big, and 9/64 (=3.57mm) too small.
What is the right size???😳🤯😭

Comments

  • pep.fermi
    pep.fermi Posts: 330
    I understand from the FSA own instructions, the holding nuts supposedly need T30 torx tool, but definitely these are hex, not torx....😭
  • wilberforce
    wilberforce Posts: 295
    Are they not T30 but from the other side of the chainring from that which you have taken the photo?
  • pep.fermi
    pep.fermi Posts: 330
    Good point, thanks, I will check the other side (which is much less comfortable to access).
  • pep.fermi
    pep.fermi Posts: 330
    Thanks. Yes, I will remove the crankset and the BB and I will report.
  • pep.fermi
    pep.fermi Posts: 330
    oxoman said:

    Your BB won't need removing just the cranks, unless it's foobarred of course.

    Well, yes of course you're right.

    But the story is longer: I want to remove the BB, to change it, it's nosy. And in the process of studying the whole thing I came to notice the little nuts holding the chainrings do not look as I was expecting them....