Originally Posted by Hollister
What would typically happen when hitting a stiffer shaft with a too low swing speed?
When hitting my regular graphite shafts, my shots get way too much height.
In purely physical terms, not much difference I think, at least between single flex codes.
1. Maybe a little less delivered loft, but less difference than you'd see bending an iron 1* or 2*. Depending on your swing, you might not see any difference at all in terms of loft. Not a big issue in middle and short irons - but less margin for error at the longer end of the set.
2. Clubhead speed should not change - unless the stiffer shaft is also considerably heavier.
3. Shots, especially mishits, are going to feel harsher with the stiffer shaft.
4. The biggest difference in performance, I think, is almost psychological, where either the feel of the stiffer shaft, or even just the idea that you're playing a harder shaft, encourages you to make a harder swing - perhaps harder than is really optimal. Timing and co-ordination are liable to suffer, and I think this is where, occasionally, you hear people saying that a change of shaft yielded a few mph of clubhead speed. Where a shaft is much too stiff, there's a danger of getting caught in a vicious circle passing through points 3 and 4.
Then again, not everyone is profoundly affected by the feel of the shaft if they don't know its actual flex. I play either R or S happily - and to be honest, I don't really perceive much difference. I've never knowingly hit an X flex, although I've had a couple of woods where I've suspected the shaft of being way too stiff for me and they were always horrible to hit and I never felt like I could put a good swing on them.
Lastly, I don't know about the 1998 vintage, but in Hogan's vintage years - their Apex 5 shaft was an out and out beast. Lots of folk considered the 4 equivalent to DG X.