Uggh. Sorry I don't have photos available...
I'm savaging an early 80's Fuji Grand SE that had a worn out Fuji-branded Sugino crankset. The type with a five-fingered swaged outer chainring. I dug out a three-fingered Sugino Maxy (52 x 40) of the same era and mounted it to the original BB spindle, after removing and repacking the BB. The freewheel is 6-speed SunRace (blech), and the chainline appears centered (that is, the large to 3rd highest cog appears straight, as does the small-to-3rd lowest cog).
The chain is a new KMC Z-series 6/7-speed.
So here's the problem: When in the inner chainring, the chain rubs against the inside of the larger chainring, when the rear is in the highest (outermost) cog, and when in the neighboring 2nd highest AND 3rd highest cogs.
The inner chainring is removable, and there are original spacers. I'm thinking that changing the spacers so that there's no rubbing in the 2nd highest - that's the right solution. Meaning that I'll allow the chain to rub the outer chainring when fully cross chained, as a reminder to the future owner not to cross chain.
I haven't measured yet, but I'm thinking that this might be a move of about 2-3mm inboard for the inner ring. So, I'm creating a gap between chainrings (I'll need to check whether the chain can get trapped between shifts).
My other option is to swap on a different crankset with smaller difference...
Thoughts on allowing the crosschain to rub, or should I move the inner chainring further?