Mike,
French bike makers frequently got around the problem by just using a piece of cable housing wrapped around to the back of the seat tube. It looks rather crude but it's worked in many cases for years.
I had a 1980 Bertin with Campy style brazed on bottom bracket cable guides. The Simplex Super LJ front derailleur had the control arm on the front side of the seat tube. The factory used some small diameter cable housing wrapped all the way around to the front of the seat tube without stops at either end. It worked without a problem for years.
When I finally got a gold anodized SLJ derailleur with a rear control arm and eliminated the cable housing, I didn't notice any difference in the shifting!
Chas. Colerich Oakland, CA USA
Michael Anderson wrote:
> Bob, John,
>
> John: I was wrong with the 22 mm. The correct french tube dimension is
> of course 28 mm, and nothing else.
>
> The bike, a Stella from the 1960s, has brazed-on cable housing stop for
> the front derailleur on the down tube. Preferably, I would like to find
> a cable stop to put on the seat tube, below the derailleur. This will
> rule out the original Simplex double cable guide model 3606-L Bob
> mentions, however.
>
> Thank you both for your help.
>
> Mike Anderson
> Gothenburg, Sweden