I'm working on a '83 Miyata 610 I picked up and am having trouble with the crankset. I could see that there was a lot of chain damage to the crankset where the chain had dropped between the rings but I though I could figure it out, usually someone just installed a ring backwards. This triple has all three rings held together with the same chainring bolt, it doesn't have the separate attachment for the granny gear.
Oddly enough, the thing was assembled correctly, but the chain can still fall between the two outermost rings. I tried all sorts of combinations, but ultimately, the middle ring is set so the teeth are 'closer' to the outer ring, and i can't close the gap any more. The chainrings aren't bent.
I did get it to work by turning the outer chainring around. This moved the teeth closer to the middle ring. I know it's wrong though, because the outer ring has a recession where the chainring bolts should sit and now it's backwards and the bolts don't sit recessed.
The chain could be the wrong chain, but it really does look like a wider 6 speed chain so I doubt it's the problem.
Let me know if you all have any ideas or have seen this before. Thanks.