the serial number on my early 80s Batavus Competition is: 8 100383
I was unaware of any serial convention as I measured the bike closer to 59cm than 58 (CTC). And the catalog picture version + spec of a 1982 matches mine to a T.
Ishiwata 022 tubing is one reason I bought it, as Columbus and Reynolds predominate my bikes.
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Vintage, modern, e-road. It is a big cycling universe.