Typically too old to tour North America (2,7)
I believe the answer is:
on average
'typically' is the definition.
(I've seen this before)
'too old to tour north america' is the wordplay.
'too old' becomes 'overage' (I've seen this before).
'to tour' indicates putting letters inside (to tour can mean to go around).
'north america' becomes 'na'.
'overage' going around 'na' is 'ON AVERAGE'.
(Other definitions for on average that I've seen before include "Usually" , "typically speaking" , "Generally" .)