I’m adding 1/2″ extensions to iron shafts KBS Tour 105 parallel tip in Stiff. I know this will change the swing weights by +2.5pts but how may this affect the shaft flex? Thanks in advance.
Frequency will decrease slightly (I would guess a couple of CPM). This would be for the overall shaft stiffness (Butt). I doubt if that would be a discernible amount to most individuals.