6 speed chains, even the Shimano ones, are wide enough that you can
just do your normal break and repin, to my knowledge. I specifically
stopped using the bastards when they got to the two or three different
colored replacement pin depending on chainwidth stage, because I had
a friend or two who did significant damage to rear D and dropout with
a moving fast chain separation using a Shimano chain.
8 cog rear is as much as I own, so not really an issue for me. With regard
to those twist grip shifters, In my lifetime at the coop, I've tried to recable
about twenty of them. I think I successfully managed two of the earlier
ones (came apart by loosening an allen set screw).
So try not to personalize it. I usually tell people if they want to go at it,
here's how it comes apart and there's where the cable goes, good luck.
