I'm rebuilding the Shimano drivetrain on an old 7 speed touring bike. Can I use a modern SG-X 8/9 sp chainring and still have it shift properly? Yes. Just be sure to adjust the derallieur height on the down tube if your new chainring is
a: the largest, and
b:a different number of teeth compared to the old one.
The new one will probably be narrower than the old, so also check the end stop positions for shifting. Yes !
As the other guy said, you will have to fiddle about with the front derailleur, but it's ok!
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