I’ve been noticing an odd knock/click in my drivechain when the driveside crank is parallel to the downtube. I can’t find a stiff link in the chain and I’ve checked that the BB is running smoothly, so it’s not a BB bearing. I’ve noticed that this only happens when I’m in the middle ring (yes I’m still riding a triple) so I’m assuming that it’s a worn or bent tooth.
There’s nothing obvious to my eye and, watching from the non-driveside, I can’t see movement in the chain when the click occurs so is there anything else I should be considering before trying a new chainring?