Greetings..

I have not posted in a while as I have had other things going on. However, I have been working diligently on the 1981 Centurion Super Tour 15 I obtained at a garage sale and have basically made it ridable again. As I have come down to the final adjustments it has come to my attention that POSSIBLY a previous owner altered the triple chainring by adding a very small inner ring for very low speed climbing but left the original front derailleur on it. When I got the bike the whole section that moves the chain side-to-side was literally torn off and I wondered how that could have happened. Fortunately, I found an exact replacement on eBay and mounted it up but the same situation came up for me - the chain drops so far down on the lowest cross-ring that it rubs on the rear cross-piece. Possibly the thought was to remove that cross-piece entirely resulting in the shifter being caught in the chain???
The difference in diameter between the large and middle rings and the smallest is considerable. Is there a derailleur that would better shift to all three or can I 'modify' this one to work?

Thanks in advance for your suggestions!

Wil