Charlie,
On page 199 of Frank Berto's book, "The Dancing Chain", there is a drawing of the first generation Simplex retro-friction shifter with a caption which begins "1973-95 Simplex Retrofriction shift levers...."
So, perhaps Mr. Berto has it on good authority that 1973 was the year of introduction.
My '73 Raleigh RRA was equipped with Simplex SLJ derailleurs, however the shift levers were not the retrofriction variety. That deficiency has since been corrected, however. :-)
The shifters would probably be period correct on a bike from 1975, but who'd fault you for putting them on even if they weren't?
The older and original style retro-friction levers with the trade mark Simplex "S" in a star might be nearly impossible to find, however.
Ed Braley
Falmouth, Maine
> Folks:
>
> Could someone inform me of the approximate introduction of the Simplex
> retrofriction shift levers? I recall having read that they were a favored
> substitution for Campagnolo NR shifters in the peleton around the '80s.
I'm
> wondering if they showed up a bit earlier than that and whether they would
be
> period correct for bicycles from around 1975 on.
>
> Thanks,
>
> Charlie Young
> Honeybrook,
> PA