Shaft Flex Junior Fitting

[triguy67]

My son is a mid 80's golfer 13 years old. He had been using vt max custom junior clubs.  He is growing out of them and it's time for a new set of irons.  He is 4'11 with a 73 mph swing speed with a 7iron.  All charts point to an A flex shaft. My question is how much does cutting down the shaft change the flex.  Does a Ladies flex become an A flex when you cut down 1.5 -2 inches.  Does an a flex become a regular when it's cut to size?  I know shortening the lever will decrease the flex.  I just don't know how much.

thanks

[Jam-ez]

Hi. Shaft weight is far more important that flex. I'd recommend seeing a fitter/builder who is able to see if he strong enough to progress into an adult headweight, with a shaft of the correct weight and playing length. They will be able to make them a touch longer than necessary so they last a good couple of years, then the same head can be reshafted when he needs a heavier shaft.

[triguy67]

Thanks Jam-ez,  He has been using adult driver, 5 wood and hybrid heads with a custom junior shaft for the past couple years.

We did some initial tests with trackman and he did well with a m4 head and a shaft 55 grams or lighter. At 60g it was getting too heavy. A women's shaft showed some signs that the flex was starting to get too light.

The problem I had is finding a fitter that REALLY understands junior golfers and how their small stature applies to golf equipment.  When you find someone, they don't really stock many heads and shafts to try combinations to get an accurate fit.

[triguy67]

The 2 fitters I talked with were unable to answer the question I posed here.  How stiff would an A flex or an L flex shaft become if it were cut to size and how would that effect his ball flight.

[Jam-ez]

There a couple of very knowledgeable independent fitters in the south with a great selection of lightweight options, see who you feel most comfortable using.

As for flex, if you cut a shaft down from the butt end the CPM number will increase.  Many people assume this result in the shaft getting stiffer but this merely just a number and has no relevance to flex unless you take playing length into consideration.  Have a look at a shaft frequency chart in google images.  As a result, the frequency of the club will decrease and the club will play softer, especially of you reintroduce additional headweight to increase swingweight that was lost in cutting the club down. However, flex really is of secondary importance here and irrelevant if the shaft is too heavy or light in the first instance. A little as 5 grams out could be the difference between a shaft working or simply just not at all.

I feel the most productive way forward would be for your son to see someone who is able to identify the correct shaft weight in the first instance. The fitter will then be able to control ball flight with a combination of different shaft bend profiles and clubs specs such as measured loft, playing length and lastly  swingweight which should never! be overlooked.

In reference to flex affecting ball flight, there are too many unknown variables here - shaft weight, dead weight, swing weight, is he currently playing with something too heavy or light in these characteristics?  These will have a more dramatic effect on ball flight than flex alone.

Hope this helps.

[Adam C]

As far as flex goes with trimming, tip trimming will have a greater influence on the flex then butt trimming. Yes in theory simply making the club shorter from the butt will increase the frequency, however it is less then you might think because you are cutting from the stiffer side of the shaft. Remember, the butt end is always stiffer than the tip and continues to increase in stiffness all the way to the butt end. There are a few exceptions with certain shafts where the very end may soften again just as there are cases where the tip end softens before beginning to stiffen again in the tip mid section. This is a lot more detail then you probably need but the point is don't worry about the butt trimming so much with stiffness. If you want it stiffer, tip trim more. Just make sure you know your parallel tip length so you don't cut beyond the taper start.

But I also agree flex is less important than weight. Best rule I can give you is go as light as you can without losing control/consistency. You want him swinging the club, not the other way around.

[triguy67]

Thanks guys, this was exactly the info I was looking for..