Finally finishing up the "renovation" (cleanup) of an early 70s Supercycle Tour de France (a very lightly respec'ed Motobecane Nomade). The buildup went really well until the very last piece - setting up the front Alvit derailleur. Two problems:

First: while it seems obvious how to put in the cable (and I have another bike with the same front to compare), when I put it together the cable slips easily. Here are some pictures of the setup before cable applied and after. Can anyone point out what I am doing wrong? If I flip the funny washer over, run the cable over it and tighten the nut I get better grip but a) its clearly not supposed to be done that way, and b) it still slips fairly soon.

Second: I have the low limit screw backed all the way off and while the cage is clearly to the inside of the chain on the small ring, shifting to the small ring almost always doesn't work - the chain only moves enough to drop down on top of the teeth of the small ring where it quickly jams. Is there a recommended height off the large ring and angle of the cage to make these work really well?

Before cable attached - clearly a channel/flat for the cable to run in.

"Logical" (to me) way to attach.....

Your threaded bit is broken - look at this:




Yours is missing the section outboard the V.

Took me forever to dig out a Huret and photograph it, so even though I'm late to the party, maybe this photograph will yet be of some value?
Your "base" should have a slot, not a ledge.
Perhaps you could cut a slot in the base on the other side of the threaded post?

oneclick : thanks - that is clearly what is wrong. Not sure why it was working before unless it was cracked and fell apart when I removed it several months ago to start the cleaning process. Is the assembly in your picture still available from some specialist shop? If not, I am thinking perhaps drilling a hole through the threaded portion for the cable and just squeezing the cable between the arm and the nut.....if all else fails look for a replacement derailleur.....

machinist42 : didn't see your picture but that seems to me to be a great idea. If I am not mistaken the part with the slot in it is removable so I could try that on the opposite face.

machinist42 - it worked great! I cut a vey shallow slot on the other side and filed the threads flat so the keyed washer fit; flipped the shaft over and it all went together really well. Not sure how long it will last!

It's a good day when there is a machinist around while you're trying to fix old bike components!