I have a Biopace triple that is 50 - 44 - 28 and I would like to go to a 22 inner ring for touring. Should I go to a smaller middle as well to ease shifting? what are the considerations?
If your cranks have 110/74mm BCD (bolt circle diameter) like I suspect, the smallest chainring that will work will be a 24 tooth.
You'll also need a front derailleur that can handle that wide a difference in chainring sizes.
ditch the Biopace. Go to round rings. your knees will thanks you