Originally Posted by
shnibop
i might have a pre-'78 crank on a post-'77 spindle which would put me 1.5mm outboard, which would certainly cause this problem.
I thought you want to be outboard. My other thought is that your taper holes are worn, or you really torqued the bejeezus out of the crank on installation. But if everything is original and in good condition...?
Is the inside plate of the FD actually preventing the chain from dropping? The only obvious difference I can see is that you have a different chain than would have been originally equipped.