Originally Posted by
juvela
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this set is the second generation "G2" or "Mk.II" edition created by Ets. Verot-Perrin reworking the original in 1981
the outer C/W is mis-mounted in that the small hole is supposed to go under the crank arm, it is threaded and takes a small bolt with spacer/sleeve which is designed to keep the chain from wedging between the arm and chainwheel in derailments to the outside
here is the manufacturer's catalogue page showing the model 99BIS of 1982. the holes are just there for lightening/appearance.
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99 triple for ref. Correct mounting puts the Stronglight mark opposite the crank arm. Agree that the larger holes prob for weight / looks.