Shimano introduced their first Dura-Ace "gruppo" in 1974. Around 1975 they put together a hodgepodge 600 "gruppo" made up of differing qualities of components badged with the 600 logo. By 1976 it became a more cohesive product line.
*<http://tinyurl.com/yefsx48>*
Suntour and Shimano were notorious for their "vaporware". They both introduced new products and started advertising them long before they were available.
The Shimano 600 components were billed as Dura-Ace with a lesser finish. The first generation 600 parts were far from it.
In 1976 we ordered in some Shimano 600 low flange, small flange, LF hub sets to check them out. They cost us $14 with a $17 list price. It took months to get them.
The cosmetics were disappointing but the internals were far better quality than Normandy/Atom hubs which were the most common economy hubs in those days.
I still have a set of wheels that I built with those hubs and they've withstood the test of time.
Chas. Colerich Oakland, CA USA
Paul Walker wrote:
> Anyone know when Shimano 600 group was introduced? I just found a really
> clean pair of Super Le Tours that look late seventies. Sound right?
>
> Paul Walker
> Philadelphia Pennsylvania
> USA
> Keeping winter interesting...