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@gbj_tester
Not for the first time, but then everybody can make mistakes:
ftfy
Squeezing in undersized rings does depend on how bulky the spider is and how deep the chain side plates are
e.g. 30T ring roller PCD is 121.5mm
inside diameter of chain with 9.5mm deep plates (typical singlespeed chain) 112mm
outside diameter over M8 bolt threads on a 104mm PCD = 112mm
so there's an overlap unless the bolt heads actually overlap the spider arm and the spider arm itself provides the necessary padding to let the chain clear the bolt heads. That would need 8mm holes in the spider arm and exactly zero material outside the holes