Dura-Ace history can be found here:
http://dura-ace.shimano.com/
Angel Garcia Verona, IT
On 10/12/06, Tom Dalton <tom_s_dalton@yahoo.com> wrote:
>
> It sounds like Rick is describing the first type of DA hub, which I
> believe dates back to around 1974. I first saw the later hubs that John
> describes, the later fully-polished hubs that were engraved "Dura Ace," in
> the spring of 1984. In between Shimano introduced the Dura Ace EX, the EX
> Direction 6 and the AX hub sets. I don't know the exact years for all of
> those, but my point is that there are more than two major variants on DA
> hubs. There are 4 in the CR timeframe and 6 beyond it. Then there are at
> least a couple of track hubs.
>
> There is one date I remember. I can remember seeing an ad for the new EX
> cassette hubs in Bicycling while in my elementary school library, which
> would have been late 78 or 79. Without seeing your hub, and assuming that
> Shimano discontinued fist gen. Dura Ace production once EX came out, your
> hubs are no later than 1979.
>
> Tom Dalton
> Bethlehem PA USA