Except those codes start with 1976. First generation Dura Ace came out earlier, maybe 1972 or 1973, and if the codes apply to all Shimano bicycle components, those go back far before 1976.
Regards,
Jerry Moos Houston, TX
Dennis Young <mail@woodworkingboy.com> wrote: Note the Shimano date codes page at the CR site:
http://www.classicrendezvous.com/
Z and J first generation?....Not according to the codes, way later.
Dennis Young Hotaka, Japan (what a mother of a typhoon that just visited here)
>
> I have a set of the satiny high flange Dura Ace track hubs,I believe 1st
> generation.Both hubs have a letter Z and J marking on the barrels below the
> stamped Shimano logo.Any ideas as to what these markings signify?
> Cheers,
> Todd Kielman
> Chicago Il.
> ---------------